WJ Suspension Info Thread
Well since I feel like it I am going to try and maintain a thread of info pertaining to WJ suspension information - and maybe later I'll add some drivetrain specific information.
Control Arm lenghts:
(Measured from center of eye to eye)
Stock Front UCA: 15"
Stock Front LCA: 15 3/4"
At 4.5-5" I have the following measurements on my front CA's and don't have any DW - very very minor bump steer so this is a good place to start off from (I have RE front & Teraflex rear control arms):
RE Front UCA: 16"
RE Front LCA: 17"
Teraflex Rear LCA: 18.5"
LCA Bolts: 21mm (Both nut and bolt)
UCA (Axle side) 17mm ***
UCA bolt (Frame side) 13mm
UCA nut (Frame side) 15mm (Don't need to hold this nut since it has an anti-spin washer on it)
*** This is the size of the metric grade 10.9 bolt that Kevin ships with his lift kit. The stock bolt is a T50 I believe, possibly T55:dunno:
Even though all of the bolts on my front suspension were already metric grade 10.9 (which is slightly weaker then SAE grade 8 bolts) I decided to upgrade to Grade 8. They are slightly bigger diameter and stronger + cheaper.
Upgraded UCA axle bolts to: 2.5" x 7/16"
Upgraded UCA frame bolts to: 2" x 7/16"
Upgraded LCA axle & frame bolts to: 4 1/2" x 9/16"
I then added appropiatly sized washers to both sides.
Torque specifications from 04 WJ FSM:
LCA Frame: 115 ft/lbs
LCA Axle: 120 ft/lbs
UCA Frame & Axle: 45 ft/lbs
Trackbar Frame & Axle: 74 ft/lbs
Front shocks upper nut: 26 ft/lbs
Front shocks lower nut: 250 in/lbs (21 ft/lbs)
Hub bearing knuckle bolts (the 3 12 pt 13mm bolts holding the hub bearing assembly to the knuckle): 75 ft/lbs
Main hub nut: 175 ft/lbs
Lower Ball Joint: 80 ft/lbs
Top Ball Joint: 75 ft/lbs
Rear shocks upper bolt: 80 ft/lbs
Rear shocks lower bolt: 85 ft/lbs
Upper A-arm Ball Joint nut: 105 ft/lbs (enjoy getting a torque wrench up there!)
Upper A-arm frame bolts: 74 ft/lbs
Ball joint plate bolts (3 of them): 100 ft/lbs
LCA Axle side bolt: 120 ft/lbs
LCA Frame side bolt: 115 ft/lbs
Pitman Arm Shaft Nut: 185 ft/lbs
Drag Link Pitman Arm Nut: 65 ft/lbs
Drag Link Knuckle Nut: 35 ft/lbs
Drag Link Clamp Nut: 30 ft/lbs
Tie Rod Knuckle Nut: 35 ft/lbs
Tie Rod Clamp Nut: 30 ft/lbs
Steering Damper Axle Bolt: 65 ft/lbs
Steering Damper Tierod Nut: 30 ft/lbs
That is based off of stock hardware so if you upgrade to grade 8 you can probably get away with some added torque on them - especially if you have some clunks from them. This is what happens if you torque down grade 8 hardware too much:D
Note on torquing down suspension components:
Always torque down anything with bushings when the hardware is at its normal position. For control arms that means don't torque them down until you have your Jeep back on its wheels sitting on the ground @ ride height. This is VITAL to ensure the integrity of your bushings. This is what happens if you torque it down without any weight on the control arms after 3-4 months of use.
Short guide on HOW TO replace the front wheel bearing hub assembly or a front axle shaft:
Speciality parts needed:
Sometimes removing TRE's (Tie Rod Ends) from tapered holes is easy, and sometimes you'll curse the man who invented tapered holes. The easiest solution is to use heat. I banged away at this one for hours until I applied heat and after 2 minutes of heat it practically fell off after I destroyed the head of this puller. A little burning never hurt anyone
Kevins/Kolak's 2.5" lift consists of:
An all too commonly asked question is whether you need to get new shocks. Short answer: no, you don't need them. But you'll certainly WANT them very quickly. The shocks will wear out quickly and going over bumps they will max out and make the ride very poor. I ran RE (Rubicon Express) Twin Tube shocks and they are stiff, no getting around that. The Mono Tubes are better and are worth the upgrade if you plan on sticking with the BB for a while. Bilstein & MX6 shocks are the "pimp" shocks of choice:thumbsup:
Another frequently asked question is at which point do you need a new trackbar. Lets start off with this: Getting a non-adjustable trackbar is a bad move. I ran Kevins 2.5" poly lift with the stock trackbar and didn't have any issues. It is called a BB (Budget Boost) for a reason. It is cheap. My personal believe is that once you pass the BB stage, suck it up and realize you'll need to commit some money to your Jeep and buy an Adjustable JKS Trackbar. JKS makes them for both the ZJ and WJ. A really good conversion for your ZJ is Kevins "Trackbar Conversion Kit" which runs a WJ style trackbar and a beefed up TB bracket. So once you hit 3", buy an adjustable trackbar. I like JKS, there are other brands out there though. People most certainly do run 3" lift with the stock trackbar, but I think you're just delaying the inevitable like that.
Transfer Case Drop Kits!
Don't waste your money on these. If a kit you buy has one, see if you can get it removed from the kit and if you can't, just don't install it. If you lift your Jeep 4", and install a 1" drop, you have only lifted the lowest part of your Jeep 3". You might as well have just lifted your Jeep 3" and not installed the TC drop at all. I am at 4.5" and don't need one. Generally people around 5.5" or higher start to need them, but not always.
Lots of people make them, Procomp, OME, Rusty, Skyjacker, Monroe, etc... Find what works for you. Kolak prefers the Monroe SS. I like the OME SS. The bigger the tire you put on, the faster you'll go through the SS. If you take the stock SS and compare it to an OME SS, you'll wonder why Jeep ever installed a SS in the first place. I was at 4" of lift, running 31" tires on the stock SS and it was just fine. I didn't replace it until I hit mine on a rock. Others may find they need one running a 2" lift with 31" tires. Each Jeep is different. It certainly doesn't hurt to install one sooner then later, but it can suck driving around with DW because your SS is undersized or worn out. I go through SS's more frequently then I care to admit (About every 4 months) but I beat on my Jeep pretty hard at the same time:D
Here is a writeup I did with some information on a Single/Dual SS: http://www.jeepforum.com/forum/showt...=349966&page=1
3" Lift components:
Personally, I would get this at a minimum for 3" of lift:
Kevins/Kolak's 4.5" lift consists of:
A lot of people recommend Kevins LP-2 (or LP-1) Rocker Guards (Sliders) - in fact that is what I have - but compared to the JKS Super Nerfs they don't stick out as far (about 1.5" less) so if you're looking for true lateral protection (ie for rocks) stick woth JKS Super Nerfs (Available through Kevins website (www.kevinsffroad.com), Nick (firstname.lastname@example.org) or directly from the JKS website (www.jksmfg.com))
Arlo's thoughts on mileage:
This is specific to my setup which is the 4.0L with 3.54 gearing running @ 5300ft or higher in elevation.
Arlo's thoughts on wheels:
The stock wheels on WJ's are either a 16x7" or 17x7" wheel with 6" of BS (Backspacing). If you want go move down to a 15" wheel (because both tires and wheels are cheaper + you'll get a better seal betwen the tire and wheel) then the only way you'll get it to clear the caliper is to get a STEEL wheel with ~4" of backspacing. The steel means the wheel will be thinner and thus make the inner radius larger and the decreased backspacing will push out the wheel further away from the caliper.
Arlo's thoughts on the width of wheels:
A narrower wheel will ensure a better seal between the tire and wheel when you airdown offroad. However if you have too wide of a tire and too narrow of a wheel it is bad (mmm, kay). This is just my opinion but when you have anything under a 11" wide tire stock with a 7" wide rim. As soon as you hit 11.5" wide or more, jump up to an 8" rim. If you visit the various tire manufaturer websites you'll see that for each tire they recommend a minimum wheel width which for the most part should be followed.
I run a 16x7" steel (Crager Soft 8) rim on 265/75-16 (10.4" wide) tire and I airdown to 12-14psi. I have never completely popped a bead but I have had air hissing out from a rock poking in. A narrower wheel also helps protect it from rock rash as well as protects the valve stem.
Arlo's thoughts on tires:
How to calculate between metric tire sizes (xxx/yy-zz) to SAE sizes (AA x YY"):
We'll use a "32 inch" tire for an example. I quote it because SAE and metric sizes don't match up perfectly.
Arlo's thoughts on WJ brakes:
Throughout the production of the WJ there were two different brake calipers offered. The first was in production between '99 to the middle of the '02 model year. Their weakness was applying unequal force to the rotor and thus causing it to warp/wear unevenly. In mid '02 Jeep switched to Akebono calipers to "fix" the problem. For some it fixed the problem, others still ran into warped rotor issues.
Warped rotors are diagnosed by anything from mild to heavy braking causing a pulsing or vibrating feeling in the peddle & steering wheel. The worse they get the less hard you'll have to brake to feel the warpedness (I have a copyright on that word so back off).
This link shows the new calipers on the left and the old on the right. Some people use the old style calipers and never have warped rotor issues. Others (myself included) can warp the new style quite easily. My rotors would last for only ~9 months before they were warped. I have heard the new style calipers run between $150-$350 so upgrade at your leasure if you have the old style. However since that may not fix your problem switching to a one piece rotor may be your real salvation. The Brembo rotors that I run have been great for the past 18 months I have had them - most of which time I have been running bigger then stock tires so I have been working them harder. Basically any one-piece rotor will solve the warping issue. The stock two-piece design (two pieces of metal connected vs a solid piece in the first place) is one of the reasons thought to be the reason for warping.
The new style (Akebone) are slightly larger then the original size so if you have aftermarket wheels on there check for clearence. I picked up my Brembo Rotors from www.tirerack.com
Arlo's thoughts on the speedometer with bigger tires
When I changed from stock (235/75-16) to my AT's (245/75-16) I found my speedometer to be nearly dead on. That means that when 100% stock my Jeep said I was going faster then I actually was. So when I moved to AT's there was no reason to adjust my speedometer. However when I toss on my MT/R's (265/75-16) I am about 5-6% slow - meaning when my speedometer says 75 mph, I am going 78-79ish.
WJ's are unique (bad thing) in that they don't measure the speed from the transfer case output shaft like the ZJ's do, we measure it from the tone rings on the rear axle. This means that we can't change a gear in the TC to compensate for different size tires like a ZJ can, we have to go the electronic programming route - or just be smarter then the speedometer and know to drive a little slower. For those that thinking changing the gearing in the diffs would help, it won't - since the speed is based off of the post-diff wheel speed. A TrueSpeed Calibrator (Thanks walter_da_jpr), $190ish, is a programmer that can adjust the speedometer to be accurate for larger tire sizes. Anything over 32 and it'll be pretty far off and probably worth the money to adjust your speedometer.
There seems to be some variations between years so it is best to verify this yourself. I measured all of the speeds via GPS.
If you plan on swapping out your rear axle for one w/o tone rings (ie upgrade to an 8.8, 9", D60 etc...) then you'll lose your speedometer and ABS. A way to keep your speedometer is to rewire your rear ABS sensors into your front wheel sensors - that way you'll be measuring your speed off of those wheels.
ANOTHER alternative is to swap your TC for one that has a speedo sensor on the output shaft. And then you'll have to do some investigating - you'll need a ECU (I believe) from a Dodge Dakota, to convert the T-case speed signal into a signal that the computer on the WJ can use. A lot of work and I believe JohnBoulderCO from www.mallcrawlin.com has a writeup on how he did it.
A note on lifting Grand Cherokee's in general...you get what you pay for and if you skimp on parts, you'll be unsatisfied.
Arlo's Lift Kit:
***Nierace made the comment that the JKS CA's are freaking expensive. I chose them over the alternatives of RE & Teraflex. Nierace pointed out that for that cost, you can get IRO (Iron Rock Offroad's) Long arms up front. That would be fine, except they aren't adjustable and that may be a problem for you. I know it was for me. I had to dial in my caster over a few weeks to get rid of death wobble.
Suspension & Steering Geometry
I'll add information here about the geometry of the suspension and steering of the WJ.
Function of all those black bars up front:
Drop Pitman Arm & Trackbar Brackets:
Holder for additional post...2
Holder for additional post...3
Maybe you could add this to post #6
If you guys have a question, make a new thread;) First post in here says to do so...
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