Let’s begin with a quick explanation of what lockers do. Simply put, a locker is a device that controls power distribution to your tires and control how power is redistributed to the tires in different situations, such as changing terrain and tire spin. Housed in the differential case, lockers come in two options, Selectable and Automatic. We’ll divide these into two sections for simplicity’s sake:

Selectable Lockers: These types of lockers allow the driver to control when the locker is engaged and when it disengages, hence the name “Selectable”. These lockers are controlled either pneumatically by an air compressor, or electronically by the use of magnetically charged currents.

Animation of ARB Air Locker courtesy of www.arbusa.com

Air-actuated Selectable Lockers: Air actuated lockers are usually controlled by a switch mounted on the dash. The switch controls an air solenoid that in turn sends pressurized air down a pneumatic air line to the axle housing and into the air locker in the differential. The compressed air actuates the piston and clutch gear, moving the gear into the “locked” position. The side gear is locked to the housing providing 100% traction lock-up between the two axle shafts.
The locker is deactivated by a flip of the switch, forcing the solenoid to release the air pressure. In turn the piston springs return to the pistons and the clutch gear returns to its original open position. The best example is an ARB Locker like the one in the animation to the right.

The benefits of Air Actuated Selectable Lockers:

100% traction on demand without driveline wear
Easy to install, operate, and maintain
Simple design with minimal moving parts, making it ultra-durable
No extra tire wear
Option to disengage in places that an automatic locker could not such as hill-sides or rocky areas where an open diff would perform much better than a locked one.

The disadvantages of Air Actuated Selectable Lockers:

High initial cost
Must have an air compressor
Require air hoses and fluid to work

Electronic Selectable Lockers: Electronic Lockers operate very similarly to their air counterparts, with the exception that instead of using compressed air they use electromagnetic pulses to engage and disengage the locker mechanism. These electronic signals are also controlled by a switch that the driver can easily control. An example would be an Eaton ELocker.

The benefits of Electronic Selectable Lockers:

No compressor noise
100% traction on demand without driveline wear
Easy to install, operate, and maintain
No extra tire wear
Can disengage in places that automatic lockers would self-engage, such as hill-sides or rocky areas where an open differential would perform much better than a locked one.

The disadvantages of Electronic Selectable Lockers:

High initial cost
More moving parts
Requires electricity to operate

Oxlocker: Functions the same as an Electronic locker, except using cabling to control the locking mechanism instead of electronics.

The benefits of an Oxlocker:

Does not require electricity or air to operate
Less costly

The Disadvantages of an Oxlocker:

Cheaper material
Cable malfunctioning, or getting caught on something

Automatic Lockers: This type of locking system is not user controlled; rather, it is controlled by certain conditions such as speed, torque, and tire spin. There are several different types of automatic lockers, which vary in cost and usability.

Torque Actuated: A torque actuated locker is automatically controlled by the amount of twisting force exerted on the differential. This type of automatic locker is essentially always engaged, as the driver has no direct control over the components. The locker can sense turns and it will disengage itself when going around corners, as long as you aren’t giving it gas, allowing the wheels to spin at different speeds to properly turn the vehicle. Examples include Eaton’s Detroit series Locking Differentials.

Gleason-Torsen: Similar to a Detroit Trutrac. Was more popular 15-20 years ago but they aren’t seen anymore.

The benefits of Torque Actuated Automatic Lockers:

Never have to worry about when to engage your locker.
No extra components such as switches or air lines are required.
This is the only automatic locker that can work when one tire is completely off the ground.

The disadvantages of Torque Actuated Automatic Lockers:

Almost always engaged
No way to control, completely automated
Increased tire wear

Limited Slip: Limited slip lockers are a good bridge between your standard differential and a full locking diff. These lockers are not capable of 100% full lockup; however they provide a lot better traction when off-roading than an open carrier.

The benefits of a Limited Slip Automatic Locker:

More cost-efficient to manufacture
Never have to worry about engaging it
More forgiving on the street than a Torque Actuated Locker

The disadvantages of a Limited Slip Automatic Locker:

Do not provide 100% lock-up
Requires special oil friction modifier

Spools: Spools are the simplest way to lock your differential. Simply put, a spool is a solid carrier that allows for no wheel speed differentiation. Spools are always engaged. This type of locker is usually seen in competition and drag racing.

The benefits of Spools:

Extremely cheap
Permanently locked
Allows no change in wheel speed differentiation

The disadvantages of Spools:

Tire wear
Low turning radius
Additional stress applied to shafts

Mini-spools: Mini spools replace the spider gears in an open differential into a full non-differentiating diff that locks both shafts together. This would make it just as strong as the stock carrier is.

The benefits of a Mini-Spool:

Most cost-effecient locker available
Can use the same stock carrier

The disadvantages of a Mini-Spool:

Like all other automatic lockers, cannot control when engaged
Prone to break

That’s it for almost all of your options for lockers for your Jeep. Choosing which works for you will depend on what you are planning to use your Jeep for. Will it be a daily driver as well as an off-roading machine? Do you want to control when the locker is engaged or would you rather not have to worry about it? How much are you willing to spend on the proper equipment? Just a few examples of questions you should ask yourself when making a decision. Give us a call if you still have questions and we’d be happy to help figure out what works the best for you and your build up!

A few weeks ago I got a call from my good buddy Adrian. He had blown his clutch in the middle of the desert and wanted to give me a heads up as to what happened, so I could warn/ remind others of a potential hazard of low gearing. Adrian is no dummy; he was the crew chief of one of the most technologically advanced racecars in the world. And understands exactly what caused his premature clutch failure, but a fraction of a second laps caused it all.

The scenario

You’re driving down a steep hill.  You “wisely” shift in low gear to allow the engine to do the work.  The hill gets steeper, and the engine RPM’s start to increase to redline speeds.  Quickly you dump the clutch to reduce engine speed and prevent damage.  Still in 1st gear with the clutch in, the engine RPM’s begin to drop and so does the hill.  The Jeep picks up speed…

Do you see a problem here?

1.  Engine RPM:  It’s good, the clutch is pushed in, it’s idling.

2. Steep Hill:  Ya, but it flattens out in a few yards…you’re only going 15 mph anyway, no problem

3. You’re too tired to put the transmission in neutral, and besides, it’s only a little way to flat ground, all you need to do is coast a few more feet, let the clutch out, and go.  What could go wrong?

This is exactly what Adrian thought while driving his 513-geared JK down a steep sand wash.  Here’s the problem-

Without working through all the intense math equations, here’s what happened. The rear wheels are turning one revolution to every   5 revolutions of the driveline, assuming a 513-gear ration.  The driveline now spins the tcase output shaft.  Because you’re rockin a 4:1 low, the shaft speed on the input side of the transfer case is now 20x faster than the wheel speed.  The transfer case drives the transmission, which in this case is still in 1st gear. Using the gear ratio of the transmission, the input is being spun at a staggering or should I say grenadine rate! The clutch disc is riding on the transmission input shaft, and because of the clutches diameter, centrifugal force comes into play and the disc, designed for about a 6,000 rpm max, reaches speeds of 10,000 rpm or more. Not Good.

This all happens in about 2 seconds, there is a sound, much like a formula one car just before it shifts.  The clutch hits warp speed and the term “big bang”, takes on a whole new meaning. The clutch completely disintegrated, and he was walking. It took about .5 seconds for Adrian to realize his injudicious actions,  (the word of the day on my phone app, I was dying to use it) and start berating himself. It’s a lot less painful, and not to mention less costly, to learn from the experience’s of others. Thanks for sharing your pain with us, in an effort to too help others avoid the same fate.

So what do we do to avoid the above from happening to our Jeeps?

Don’t coast in a low gear with the clutch depressed.

If you are dying to know what your clutch rpm would be, >>this is a good web site I visit<<

Wood out

First off, lets address the biggest factor in determining what you’ll need to be able to utilize the High Steer Kit effectively, that is, your suspension.

The High Steer Kit was originally designed to be used with the TeraFlex TJ MAX-LCG suspension system.  This system, which utilizes a front 4-link triangulation, requires a High Steer Kit in order to properly align the drag link and tie rod to be parallel to each other.  There is no other option since the MAX system does not use a trackbar.

The benefits of a High Steer system installed quickly leaked over to owners of the PRO-LCG suspension system, which is a 4-link trackbar system (sometimes called a 5-link system).  The important thing to know for using a High Steer Kit with a PRO suspension system is that you’re going to need a couple extra parts that aren’t included in the regular High Steer package in order to correctly install it, as well as a minimum 4″ lift; however, we strongly recommend 5″+ to allow for proper clearance.  Because the system gained so much popularity with PRO suspension systems, a separate kit called the High Steer Kit for LCG Suspensions was designed that includes a few more necessary parts which are: 1) 4″ quick disconnects and 2) left and right swaybar mounts.

The swaybar mounts and disconnects are crucial for proper installation of the High Steer Kit on a PRO system because it is necessary to move the swaybar away from the drag link and tie rod so they don’t come in contact.

Let’s take a look at the diagram on the right (click on it to enlarge).  This contains three different alignment configurations; we’re going to focus on the top and middle sketches. The top sketch shows a high steer kit installed with a stock track bar (notice the angle the drag link makes with the track bar). The key to proper installation of the high steer system is to have the trackbar and drag link as closely parallel as possible. As you can see in the top sketch instead of being parallel the two make a very acute angle.  This alignment would result in horrible handling and a dramatic increase in bumpsteer.  In order to correct this, three additional parts are needed which are not included in the package.  These are a custom trackbar and both frame and axle side trackbar brackets.

Until recently, you had to buy all of these separately.  We’ve finally come around to bundling them all together in a nice little kit- p/n 4923200.  This kit is crucial on a PRO-LCG system because it allows the trackbar to align parallel with the drag link of the High Steer kit.

Now, lets go back to the diagram. If you look at the middle sketch, you’ll see two orange brackets that have been installed to the track bar. The top bracket attaches to the frame while the bottom attaches to the axle. With these brackets in place the trackbar is parallel to the angle the drag link makes.  Now, you might not always be able to get the two exactly parallel, but the goal is to get them as close as possible for maximum efficiency and control.

One thing to be aware of is the caster alignment of your vehicle after installation of all these mod’s.  Having too much negative caster will cause the bracket from the trackbar to come in contact with the front differential…and that wouldn’t be a very fun experience to have happen.

Here’s more or less what a correctly installed system would look like with all the equipment we talked about here. Notice how the trackbar and drag link run parallel to each other:

That about sums it up for the High Steer Kit.  If you have any more questions or concerns feel free to contact customer service at (801) 713.2303 for more information.

How to measure the backspace: First, lay the wheel on a flat surface, front side facing down so the part of your wheel that touches the axle is exposed.
Second, Take a yardstick and lay it across the top of the rim, from one side to the other. If there is a tire on the wheel, you need to lay a flat edge the correct size of the rim, from one side to another, allowing it to lay flat onto the top edge of the rim, and not on the tire.

Next, measure the distance from the inside mounting surface of the wheel (where the wheel mounts to the axle hub on the car) to the lower edge of your flat ruler/stick lying across the top edge of the rim. For example, the distance from the mounting surface of the rim to the top edge in our picture is about 4.5″. The distance measured is your backspace measurement!

How to fix it: Now, lets say you’ve figured out you have a problem with backspacing, either your tire is too close or too far away, how do you fix it?

If your tire is too close, meaning it’s probably tearing up your fenders and wheel well, then you know you have too deep of a backspace, the easiest way to fix this problem is to buy some wheel spacers to shorten the distance from the axle hub to your wheel.

If your tire is too far away, meaning that you’re throwing dirt, mud, rocks, small animals, etc into the air…then you know you have too shallow of a backspace. Sadly the only true fix to this problem is to buy some new wheels that fit better onto your vehicle.

After a Jeep has been lifted past a certain height, ride quality and handling issues may be noticed. There is no set height as to when these issues may occur and will vary from Jeep to Jeep. At this point the owner may choose either long arms or short arms to be put in place of the stock control arms. The higher a jeep is lifted, the more the axle end of the control arm is pointed to the ground. The steeper that angle is, the harsher the ride and the worse the handling can become.

Refer to the TeraFlex Control Arm Comparison on the TeraFlex Suspensions Website for more detailed information on the different types of control arms.

Short arms: Generally a full set of eight control arms may be installed within a few hours. No welding is needed because the short arms use the factory brackets. One benefit of short arms is that you can now adjust the caster angle, which is the correlation between upper and lower ball joints on a vertical plane. Alignment angles are very touchy so please don’t try to adjust your caster, take it to a well known off road shop that deals with alignment angles on lifted vehicles. Another benefit to adjustable short arms is that you can also adjust your pinion angle. Pinion angle is the angle of your pinion to the drive shaft. You want your pinion angle to be in straight line. Short arms can be installed and purchased in pairs at a time. This can help keep the owner from a larger up front cost by purchasing the front lowers first, then rear uppers. Followed by the front uppers and rear lowers. Higher lift jeeps will not have as nice a ride compared to shorter lifts. This is due to the angle of the control arms.

Long Arms: Typical installation of a Long Arm upgrade kit or complete Long Arm kit can be up to 19 hours if installed by a qualified technician. Installations may involve cutting off factory brackets, cross members, drilling new holes, welding and grinding. Some kits are a bolt-on design. The installer will have to drill multiple holes for installation. Other kits are a weld-on kit, requiring a skilled welder. Either case can lead to higher installation cost and labor times vs. a Short Arm installation. Generally a long arm kit is installed all at once. However it is possible to install either the front or rear at different times. The big benefit of Long Arms is that the control arms are more horizontal, this makes ride quality and handling improve greatly for higher lifts. A jeep with a long arm kit can travel faster off-road. The street ride is not compromised but enhanced. This is a major benefit over a Short arm kit when on any trail. With a Long Arm, you can get more flex and travel out of your suspension.

For further information or if you have any questions call us at (801) 288-2585.

There’s an awful lot of confusion out there when it comes to vehicle warranties and installing after-market products on your car. Simply and briefly, this article is meant to inform you about your rights in regards to your vehicle’s manufacturer warranty and the ability to modify or upgrade your vehicle with after-market parts.

In 1975, the Supreme Court passed a law called the Magnuson-Moss Warranty Act. Among countless other things, this law included the standards to which companies offering warranties had to comply in relation to 3^rd party or after-market products. First off, I’ll give you the technical version:

15 USC 2302(c) Prohibition on conditions for written or implied warranty; waiver by Commission.

No warrantor of a consumer product may condition his written or implied warranty of such product on the consumer’s using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade, or corporate name; except that the prohibition of this subsection may be waived by the Commission if –

(1) the warrantor satisfies the Commission that the warranted
product will function properly only if the article or service so
identified is used in connection with the warranted product, and
(2) the Commission finds that such a waiver is in the public
interest.

So what does all that mean? After a little bit of in-depth research, we figured out what it’s saying in layman’s terms:

The company providing the warranty (warrantor, as they call it in the legal system) cannot require the customer to use only company-branded parts on their product for it to retain its warranty. For example, if I own a JK Wrangler and decide to put an after-market suspension system underneath, the manufacturer’s warranty still applies to all original parts left on the Jeep. The warranty cannot be voided just because I did not use a Jeep branded suspension system.

Now obviously if I added an after-market suspension kit my suspension system would no longer be covered by the warranty, because the original parts are no longer there. So be careful that the aftermarket products you are installing come from a reliable company and include their own warranty.

Also, many times dealers will try to tell you that if they install after-market parts onto your vehicle the warranty will remain intact, but if you go to a 3^rd party to get it installed they will void your warranty. This is what is called a ‘tie-in-sales provision’ and is also illegal according to federal law.

That’s the basic idea of what to expect in regards to your vehicle’s warranty. To sum it up:

1- YES! You have the right to install after-market additions to your vehicle while retaining your original warranty for all stock components.

2- The company offering the warranty cannot void the contract simply because the parts you use are not company-branded parts or because someone else installed the parts for you.

3- Although the warranty will still apply to all stock parts, additions and after-market parts are NOT covered by the vehicle’s warranty.

For more information visit the FTC website HERE.

Many of you know Dave Call as Doc, but after this article, you may know his Yellow Unlimited better than you’ll ever know him…

Doc’s 06’ Jeep Rubicon Unlimited utilizes a 6-speed manual transmission and flexes through incredible obstacles with a TeraFlex 6” MAX-LCG 4-link Long Arm Suspension Kit incorporating the TeraFlex High Steer Conversion and TeraFlex Quick Disconnect System.

Doc runs 37” Toyo MT’s on Champion Bead Locks. For rescuing his friends, he bolted on a Warn HS-9500 Winch, and for rescuing himself… he has a RockHard bolt in roll cage and Poison Spyder Rocker Knockers. Not forgetting his undercarriage, Doc has the full TeraFlex brand skid plate line protecting the engine, transmission and gas tank.

Doc has a built drive train with a Dana 44 in the front with Alloy USA Chromoly axle shafts, a Dynatrac diff cover and 4.88 gears. As far as the rear axle, this was Doc’s only weak spot. After breaking his Rubicon 44 rear axle multiple times he brought it in to TeraFlex PLUS to be replaced with a TeraFlex CRD60R – unbreakable even by the toughest of rock crawlers. The beefy CRD60R bolts right on and with extended brakelines, Doc was ready just in time for last weeks trail run to Five Mile Pass.

On the trail run Doc was asked if he felt any difference with the new Tera CRD60R. He said his confidence was”through the roof!” No more walking on eggshells; it’s game on for the Unlimited. Doc has always been a ‘no fear’ guy, but now his drive train will hold up to his conquer-all driving style.

Along with the new CRD60R, Doc had a new Tattons driveline installed. The higher pinion on the 60 helped with his pinion angle problems. Now even with his 6″ lift, he has no driveline vibration. He also had a 1350 u-joint put in on the differential side and changed the yoke on the front to 1310 in order to run u-bolts instead of straps offering more security to the yoke.

With a Rubicon 4 to 1 transfer case, Doc is now ready to hit the trails with even more confidence.

Photos courtesy of Dave “Doc” Call and his jealous friends.

TeraFlex PLUS is the latest evolutionary stage of a company that started life almost 50 years ago in 1959 as MEPCO, which was an acronym for Military Equipment Parts Company. MEPCO (MEPCO Jeep, MEPCO 4×4), was a parts supplier for Jeeps® and other military vehicles for many years, with the focus being primarily Jeeps. MEPCO’s ability to access hard-to-find parts, and the knowledge contained behind the parts counter earned them a reputation that was second to none. MEPCO charged along as the resident Jeep parts expert along the Wasatch Front for many years. To add to the package, they added a full installation shop to provide product installation in the late 1990’s.

In mid 1996, with the introduction of the 1997 Jeep TJ Wrangler, and its smooth-riding 5-link coil suspension, MEPCO saw an opportunity to design a suspension that would meet the needs of the first-ever coil sprung Wrangler. So, with years of MEPCO expertise behind it, the company Tera Manufacturing, Inc. was created. Tera Manufacturing began producing its first TJ suspension kits under the “TeraFlex” brand name. TeraFlex quickly became an innovator in the industry, being the first to provide a production lift kit with flexible arms for the TJ’s. They were the first to have a slip-yoke eliminator for the NP231 transfer case, and TeraFlex was also the first (and now only) company to produce a 4:1 low-range kit. The TeraLow 4:1 was even used as a platform for Jeep engineers to help design the NP241-OR case that is used in 2003 and newer Wrangler Rubicon editions.

The end of 2003 brought more changes to MEPCO with the addition of their All-Terrain Service Center, which expanded their service knowledge and abilities. MEPCO gained the capability and equipment to perform more services on more vehicles, and were also able to expand their custom fabrication department.

MEPCO’s focus has changed dramatically over the years. With the scarcity of military Jeeps and 4×4’s, the dwindling supply of parts for them, and the addition of a sister company that built mainly Wrangler components, MEPCO’s concentration was shifted towards suspension systems and off-road accessories for late model Jeeps. With this shift in business, a face-change was in order to communicate to the public their new dedication to be the source for all late model Jeep vehicles.

In September 2005, MEPCO’s name was updated to TeraFlex PLUS – Jeep Adventure Outfitters, to reflect this new mission. Along with the name change, a more refined list of parts and services is offered to cater to the growing crowd of late model Jeep owners.

We at TeraFlex PLUS continue to serve the off-road community much the same way as MEPCO did in its history, as the resident Jeep experts along the Wasatch Front. TeraFlex PLUS continues to grow and expand and is proud to offer online sales on our website, in addition to our serving customers in our showroom and full-service shop. Our staff has grown and continues to have a reputation for up-to-date knowledge and skills. You can’t find a better source for Jeep aftermarket products. We are continually focusing our efforts in order to best serve the active off-road Jeep® market.

Bryson Tsujimoto

The current laws were revamped in 2001 with the help of the Utah 4 Wheel Drive Association—the previous version was extremely hard to understand and limited lift height on short wheelbase vehicles (like most Jeeps) to approximately 2” TOTAL.

I’ve listed the pertinent sections in full below for those who wish to read them, but I’ll summarize the “nuts and bolts” first:

• Allowed frame height varies between 24” and 28” from the ground to the bottom of the frame, and is determined by the vehicle’s Gross Vehicle Weight Rating (GVWR), which is usually listed on the driver’s side door or doorjamb.
24” if your rig’s GVWR is under 4500 lbs (most Jeeps).
26” if it’s between 4500 and 7499 lbs (some small to midsize trucks, full size light trucks).
28” if it’s 7500 lbs and up (most full size, heavy-duty trucks).
• Tires need to be covered by fenders or fender flares fully, as viewed from above the vehicle.

• As viewed from behind, rear tires must be shielded by fender flares or mudflaps, at least the top 50% of the tire.
• Body lift is limited to 2”. (3” total distance between the top of the frame and body, usually the factory body mount bushing is about 1” tall)
• Any suspension or axle modification or replacement needs to equal or exceed the strength and durability of the stock parts.

It’s a good idea to familiarize yourself with these laws and compare them to your vehicle to ensure you won’t have any compliance issues at inspection time, or if you happen to get pulled over. Also, there is a lot of power in the following phrase:

(a) All replacement parts and equipment used in a mechanical alteration shall be designed and capable of performing the function for which they are intended and shall be equal to or greater in strength and durability than the original parts provided by the original manufacturer.

Especially for those who choose to do their own modifications, keep that in mind. Shoddy workmanship is not acceptable, and will (and should!) fail inspection. By the same token, just because you changed the stock setup does not necessarily mean it’s illegal.

Printing a copy of the full text below and carrying it with you can never hurt, either.

Happy trails!

Carl Whitmore

http://www.le.state.ut.us/~code/TITL…m/41_04196.htm
41-6-148.29. Vehicles subject to Sections 41-6-148.29 through 41-6-148.33 — Definitions.
(1) Sections 41-6-148.29 through 41-6-148.33 apply to all motor vehicles with an original manufacturer’s gross vehicle weight rating of 15,000 pounds or less operated or parked on a highway within the state.
(2) As used in Sections 41-6-148.29 through 41-6-148.33:
(a) “Commissioner” means the commissioner of the Department of Public Safety.
(b) “Frame” means the main longitudinal structural members of the chassis of the vehicle or, for vehicles with unitized body construction, the lowest longitudinal structural member of the body of the vehicle.
(c) “Frame height” means the vertical distance between the ground and the lowest point on the frame. The distance is measured when the vehicle is unladen and on a level surface.
(d) “Gross vehicle weight rating (GVWR)” means the original manufacturer’s gross vehicle weight rating, whether or not the vehicle is modified by use of parts not originally installed by the original manufacturer.
(e) “Manufacturer” means any person engaged in manufacturing or assembling new motor vehicles utilizing new parts or components, or a person defined as a manufacturer in current applicable Federal Motor Vehicle Safety Standards (FMVSS).
(f) “Mechanical alteration” or “mechanical lift” means modification or alteration of the axles, chassis, suspension, or body by any means, including tires and wheels, and excluding any load, which affects the frame height of the motor vehicle.
(g) “O.E.M.” means original equipment manufacturer.
(h) “Original equipment” means an item of motor vehicle equipment, including tires, which were installed in or on a motor vehicle or available as an option for the particular vehicle from the original manufacturer at the time of its delivery to the first purchaser.
(i) “Wheel track” means the shortest distance between the center of the tire treads on the same axle. On vehicles having dissimilar axle widths, the axle with the widest distance is used for all calculations.
(3) The provisions of Sections 41-6-148.29 through 41-6-148.33 do not apply to the following vehicles:
(a) implements of husbandry;
(b) farm tractors;
(c) road machinery;
(d) road rollers; and
(e) historical vehicles or horseless carriages that have been restored as near to original condition as is reasonably possible.

Amended by Chapter 47, 2001 General Session

http://www.le.state.ut.us/~code/TITL…m/41_04197.htm
41-6-148.31. Standards applicable to vehicles.
(1) The following standards apply to vehicles under Sections 41-6-148.29 through 41-6-148.33:
(a) All replacement parts and equipment used in a mechanical alteration shall be designed and capable of performing the function for which they are intended and shall be equal to or greater in strength and durability than the original parts provided by the original manufacturer.
(b) Except for original equipment, the use of spacers to increase wheel track width of any vehicle is prohibited.
(c) The use of axle blocks to alter the suspension on the front axle of any vehicle is prohibited.
(d) The stacking of two or more axle blocks of any vehicle is prohibited.
(2) (a) In doubtful or unusual cases, or to meet specific industrial requirements, personnel of the Utah Highway Patrol shall inspect the vehicle to determine the road worthiness and safe condition of the vehicle and whether it complies with Sections 41-6-148.29 through 41-6-148.33.
(b) If the vehicle complies, the Utah Highway Patrol shall issue a permit of approval that shall be carried in the vehicle.
(3) (a) Upon notice to the party to whom the motor vehicle is registered, the Department of Public Safety shall suspend the registration of any motor vehicle equipped, altered, or modified in violation of Sections 41-6-148.29 through 41-6-148.33.
(b) The Motor Vehicle Division shall, under Subsection 41-1a-109(1)(e) or (2), refuse to register any motor vehicle it has reason to believe is equipped, altered, or modified in violation of Sections 41-6-148.29 through 41-6-148.33.

Amended by Chapter 47, 2001 General Session

http://www.le.state.ut.us/~code/TITL…m/41_04198.htm
41-6-148.32. Prohibitions.
(1) A person may not operate on any highway within the state a motor vehicle that is mechanically altered or changed:
(a) in any way that may cause the vehicle body or chassis to come in contact with the roadway, expose the fuel tank to damage from collision, or cause the wheels to come in contact with the body under normal operation;
(b) in any manner that may impair the safe operation of the vehicle;
(c) so that any part of the vehicle other than tires, rims, and mudguards are less than three inches above the ground;
(d) to a frame height of more than 24 inches for a motor vehicle with a gross vehicle weight rating of less than 4,500 pounds;
(e) to a frame height of more than 26 inches for a motor vehicle with a gross vehicle weight rating of at least 4,500 pounds and less than 7,500 pounds;
(f) to a frame height of more than 28 inches for a motor vehicle with a gross vehicle weight rating of at least 7,500 pounds;
(g) by stacking or attaching vehicle frames (one from on top of or beneath another frame); or
(h) so that the lowest portion of the body floor is raised more than three inches above the top of the frame.
(2) If the wheel track is increased beyond the O.E.M. specification, the top 50% of the tires shall be covered by the original fenders, by rubber, or other flexible fender extenders under any loading condition.
(3) A person who violates the provisions of this section is guilty of a class C misdemeanor.

Amended by Chapter 47, 2001 General Session

http://www.le.state.ut.us/~code/TITL…m/41_04199.htm
41-6-148.33. Bumpers.
(1) Every motor vehicle shall be equipped with a bumper on both front and rear of the vehicle, except those that were not originally designed or manufactured with a bumper or bumpers.
(2) (a) On all motor vehicles under 15,000 GVWR, bumpers shall be:
(i) at least 4.5 inches in vertical height;
(ii) centered on the vehicle’s center line; and
(iii) extend no less than the width of the respective wheel track distance.
(b) Bumpers shall be securely mounted, horizontal load bearing, and attached to the vehicle’s frame to effectively transfer impact when engaged.
(3) When any motor vehicle is originally or later equipped with bumpers, the bumpers shall be maintained in operational condition and shall comply with this section.

Amended by Chapter 47, 2001 General Session

A. Bumpsteer: most noticeable when cruising down the freeway at high rates of speed. You drive over an overpass; the quality road work causes a gradual bump in the highway. As you hit the bump, the steering wheel shifts to the right, then just as suddenly it goes back to the left as the jeep rebounds from full suspension compression. This scenario causes an unwanted and unexpected lane change. Yeah, it’ll get your attention as well as those to either side of you on the freeway.

A quick safe way to test for bump steer is to drive to a parking lot or somewhere you can stop and start without causing as accident. Start with the steering wheel straight. Nail the throttle, then immediately stand on the brake. As the front end drop, hit the gas again. This will cause the front end to drop, compressing, then lifting the front suspension. Take a look at the steering wheel while performing the whole brake/gas thing. If it is rotating or turning side to side, welcome to the world of bump steer. If it stays pretty much centered you’re probably good to go.

B. Wandering: noticeable at any speed, but generally worse at higher speeds. While maintaining the steering wheel in straight and level flight position, the vehicle darts and follows every rut and crack in the road. Trying to correct for the “wandering” vehicle often results in over steer or over compensation with a disastrous outcome. This wandering condition is often symptomatic of tight steering. Turn to the left, let go of the wheel, it keeps going left. Turn right; it keeps going to the right, with no return to center properties evident. Extremely loose steering will also cause wandering due to the inability to control the front tires movement. We’ll discuss causes and remedies in future articles.

C. Death Wobble: (My personal favorite) There’s really nothing like having a soccer mom describe what happened to her Grand Cherokee when she hit a dip in the freeway while in a slight turn at 65 mph. It’s like she is reliving the sheer terror of the event as beads of sweat build on her forehead and her voice shakes with emotion. “The steering wheel started to jerk violently from side to side. I tried to hold to it but there was nothing I could do. I hit the brakes and it got worse. I knew I had to stop, so I stayed on the brakes. I thought it would break my arms. It finally subsided when we came to a complete stop in the middle of the freeway.” I then say, (sympathetically), oh, you’ve just experienced “death wobble”, she nods knowing and replies, “yes, that is exactly what it was! We were nearly killed.” Most people who experience Death Wobble for the first time think they are the only one to have had this horrific experience. Surely an event of this magnitude would have been on the news if anyone else had experienced it. But alas, it’s quite common. If you’ve had death wobble, you know it. If you have to ask, you haven’t experienced it. This condition is very hard on front end components, not to mention the driver’s nerves. Some vehicles “go off” unprovoked and at random. Others require a small bump, just the wrong speed, or just the right combination of speed, turn, bump. This condition can be corrected. Sometimes easily, often times with much trial and tribulation.

D. Pulling: This one is easy. Let go of the steering wheel. You wind up in the ditch. Constant pressure is required on the steering wheel to compensate for the continuous annoying drift or pull of the vehicle to one side or the other.

E. Vibration: No you don’t need an alignment. We’ll address this in another article.

Dennis Wood