I'll keep everyone posted on progress, but I'm debating whether or not to put the front shims that came with the kit in...
My 1985 CJ7 is running with 33" tires and a stock suspension. I don't really off road with it, but wanted a little lift to clear the tires more. I went with a Trailmaster 2.5" lift and longer shackles (Warrior) to give it an 0.5" lift there. The kit from TM came with the front and rear shims (definitely plan to use the rear), but with a slight shackle lift, I'm thinking I might be okay without the shims...
Anyone have a similar setup or experience? My initial thinking is to go without, then see how it drives after install and see if I need to make a change. I just thought I'd throw the question out there.
Either way, I'm looking forward to getting rid of my almost flat leaf springs and the feeling of my bump stops and wheel wells being beaten every time the CJ even looks at a speed bump. :grin2:
You will want an alignment after to check your caster. The shackle lift will reduce the amount that you already have. You should had between 6* and 8* negative caster for best road manors with 33" tires.
You will want an alignment after to check your caster. The shackle lift will reduce the amount that you already have. You should had between 6* and 8* negative caster for best road manors with 33" tires.
OP, you will most likely need the shims, especially with the longer shackles. Don't half-azz it. As stated, have the alignment checked and make the necessary corrections.
OEM R&P for the late 6cyl '7' was either 2:73 or 3:31.
If those are still installed. Your're gonna hate those 33's.
X2 on put'n the shims in.
What tranny do you have?
Be helpful to all of us, if you would fill in your vehicle info.
Sorry for not having my profile more detailed. I just updated it. I have the amc 20 with 2.73 gear ratio... I don't do much off roading other than a very occasional trail ride. So far the 33s have been okay, but it's the first Jeep I've owned so I don't know any different!
I definitely plan to have an alignment done afterward and will report the caster number. From the opinions here it sounds like I'll be better off with the shims and taking them out if I need to after my alignment.
Thanks for all of the quick responses! You guys are awesome. In addition to the lift, I'm finally tackling a re-do of the bed liner (P.O. did a pretty crappy one coat job). Here are a couple of pics of the prep work!
I definitely plan to have an alignment done afterward and will report the caster number. From the opinions here it sounds like I'll be better off with the shims and taking them out if I need to after my alignment.
Don't forget the U-bolts are a one-time use only. The threads will distort after being torqued to the correct value. Once fully torqued they should never be re-used.
Today went slow... I found out that the P.O. had removed one of the shackle hanger bolts in order to fit his bumper on. And the remaining single bolt holding it together on the passenger side was loose... so I guess I dodged a bullet doing this project before that bolt broke on the road. I had to grind off the bumper mount (though it's held on in 8 other places) which took a while. Now I can fit two new grade 8 bolts in the hanger holes. So far, I have everything off from the rear suspension and most of the leaf setup back on both sides. I need to attach the last part of the leaf, the U-bolts (I have new ones) and the new shocks. Then on to the front...
The shims are odd in that they are flat but the springs are obviously rounded leaving me very little of the guiding nub to fit into the hole on the axle. I'm guessing they form together once things are tightened a bit? Luckily I have a friend helping out that can work the jack while I work the axle.
Photos attached of that bumper/hanger setup, plus old and new.
As for the 33" tires... they came with the jeep when I bought it a few years back and haven't given me trouble thus far. I don't do any serious wheeling and probably only put 1,500 miles on the CJ a year. Down the road, yeah- re-gear and one piece axles, but at the moment this is the project I have chosen to tackle with my budget. :smile2:
The shims are odd in that they are flat but the springs are obviously rounded leaving me very little of the guiding nub to fit into the hole on the axle. I'm guessing they form together once things are tightened a bit? Luckily I have a friend helping out that can work the jack while I work the axle.
You need to remove the center bolt from the springs, and put it through the shims. Use it to bolt the shims to the springs. I have seen a few shims pop out that were just slipped in place.
You may need longer center bolts, depending on the thickness of the shims. As long as you can get a full nut on, you are good with what you have.
A C clamp or two on the springs before you remove the center bolt makes easy work of them.
Oh- interesting. I thought it just sandwiched between. Does anyone have a picture of that set up? The shim still goes on the top of the springs, right?
Here's what I've got on there. I still haven't attached anything other than the leafs to the CJ. These are pics of the rear suspension and the fat part of the shim is toward the front of the jeep.
I am in the process of reversing a install like this......where to start and stay on point.....
Those are aluminum shims, that do not bolt on........not good, as you see they have taken up almost all of the locator pin for the axle. Steel bolt on shims require you to take the center pin out of those springs and you bolt the steel shims to the spring.......that is once you determine what you need for castor and what you need for pinion angle....
I know you do not want to hear this, but I would not install ANY lift shackles as this rotates the axle and changes both castor and pinion angle.........things you might have to fight already just with the lift springs.
You might lucky and still be close enuf on both........you will soon know if you do not check both with a angle meter as it will wander/drift and shake.........and the front drive shaft will vibrate......
The covers some of what I have been correcting on mine from a lift kit and 1 inch lift shackles.......
You might also get by with the stock length brake lines up front.....maybe.
Then you have drag link steering geometry , bump steer etc etc etc in the front.
Out back is pretty straight forward.........brake line length, and pinion angle.......she will buck and vibrate if the angle is not correct.......lift springs might keep it close euff, but the lift shackles will change that more........
A 1/2 lift shackle might not be as bad as a 1 inch lift shackle.........but me and my jeep were both happy when I went back to the stock shackle length.
I would at the least check the castor angle with the aluminum shims so you can figure out which steel shims to get.....2 degree.....4 degree.....6 degree........8 degree............havine a 1/16th of inch of the spring locator pins in the axle flange is no good at all.
Also take note of the drag link angle from the pitman arm to the joint and watch how that moves with the lift and the shackles..........there is some play/forgivness with the ball joints for angle, but the more angle the more bump steer problems you will get, a long with increased wear on the front end components.
A drop pitman arm will correct most of a 2.5 inch lifts differences.
I wish you the best of luck........now is the time to get it right while you have it apart.
Think of a yard stick facing front to back under the jeep............imagine the fulcrum point in the center of the stick, as you add shims or lift shackles , raising or lowering the front of the stick, causes the back of the stick to raise and lower.....back being your pinion angle..........the pinion angle and castor angle are set/welded into the axle.
A movement in one gives the exact movement in the other........assuming the lift springs keep everything exactly the same...castor and pinion, the lift shackles will reduce your castor angle, thus increasing your pinion angle.......those 2 degree shims will rotate the axle to increase your castor , while at the sime time rotating the pinion angle towards the ground.
You have a approx 2 degree window in the castor for the spec......which may or may not give you good handling at either end of the spec.........I do not know the spec for pinion angle to front transfer case angle, but it has to be pretty much spot on with the same angle on both........I believe the rear is the same, as the pinion angle and the transfer case angle have to be spot on or bad things happen.
Castor angle is pretty straight forward ......pinion angles get more complicated.
There are some good youtube vids with mock drivelines set up and painted so you can see the effects of mismatched pinion to transfer case angles ......
I know the post is long.......but I am knee deep right now in correcting all of these things on my jeep.
I just wanted to give you a idea of what is happening with the different parts of a lift........it is changing geometry of all kinds of stuff, which may or may not be a problem and some of it is not just a simple fix as those nice little shims would have you think it is.....
Looks good-Does that shim just 'sit' on the center bolt?
Don't tighten anything till the axle is in place. Make sure the center bolt goes back in place in the axle's spring perch.
LG
I ended up getting them in and once the u-bolts were tightened, the center pin went in fine. I think I'm going to get it all on and see how the pinion angle looks and how it drives. If I need to make an adjustment, I'll definitely order a set of the warrior shims!
Also, upon second look at the AMC 20, I actually have a 3.31 gear ratio (I thought it was stamped "D", but it's actually a "B"). So, not ideal for 33" tires, but better than 2.73.
All finished up! As any CJ project goes, there were countless bumps along the way. I already mentioned the one-bolt shackle hangers in the back. In the front, they were just bolts that were damn hard to get off. I replaced the sway bar bushings and had to take it all the way out to hammer out the connecting bars, even after the nuts were off!
I'm going to take it to a 4-wheel shop next week to get an alignment and get their thoughts on pinion and caster angles. I think I also think I've got a u-joint going bad. I would hear an occasional ping here and there before and now getting a few more.
Before and after photos below! It looks like it now rides how it should! Nighttime photos are the befores (cooler looking photos, but lower suspension).
I forgot to add, aside from the pinging, the test drive was great! It rides so much better than before! No more constant bump stop and wheel well hits on the tires!
Once I get the alignment done I'll update you guys again. Thanks for all the help!
Before taking it in for an alignment, I figured I'd check out that pinging sound. I had heard it prior to the lift, but it was more pronounced after.
I searched a little online and found that it doesn't appear that tough to change a drive shaft u-joint, but I can't check the balance of the shaft myself. I found a local drive line shop to replace both joints and balance the shaft for about $100. Since it's such a crucial component I figured the extra few bucks were worth having a pro check it out.
As soon as I put the shaft on the counter (insert joke here), the mechanic immediately saw the problem. See pic. Definitely not a smooth surface under one of the u-joint caps.
I pick it up tomorrow and plan to get the alignment done next week!
I would get a cheap angle meter at lowes...under 10 bucks ad check your pinion angle compared to the tranfer case angle...those need to be right on or you will end up in the same bad u joint boat you are getting fixed now.
Both ends of the shaft where they connect to the yokes need to be the same degre angle or problems result.....
Oh wow- those are great videos. I knew pinion angles were obviously important, but that first video is very eye-opening as to why. I'm going to have the 4wd shop that does the alignment also measure the pinion angles as I'm sure they do it often (they work on a lot of Jeeps). Thanks!
I know it's been a while since I updated everyone, but some new stuff.
I got the drive shaft back on with new u-joints. Honestly everything rode great. I took it to the 4WD shop and had them do an alignment and check my pinion angles. They measured transmission output at 3 degrees and pinion angle at 9 degrees (because I put the shims on with the fat side toward the front). The guy at the shop- who's been working on jeeps for 20 years- said, if it ain't broke don't fix it. I had no vibrations, everything rode well.... but I was worried about phasing and the 6 degree difference might hurt in the long run. I rode on it like that (weekend driver) for about 6 months.
So, today I finally flipped the 2.5 degree shims to where the fat part is now at the back, rotating the axle forward. I figured that way I'd have a 3 degree output and a 4 degree pinion angle. With one degree difference, I imagined I'd be in good shape. Now... it rides well at low speeds, but when I got it up to 40mph to 55mph, I hear a low hum/vibration. Since I only changed the shims (didn't rotate tires, etc), I'm guessing that for some reason I'm getting phasing or something. I was very surprised to say the least... and annoyed.
I'm wondering if I should get another degree higher shim (the ones in now are 2.5 degrees), turn them back around (if it ain't broke...) or take them out altogether. Thoughts? The shims were in good shape when I flipped them and didn't show signs that they had shifted over the course of 6 months.
The more I think about it, I wonder if the shop did the measurements with the frame jacked up or something... they shouldn't have, but everything I'm reading it looks like I put the shims on correctly the first time (fat part toward the front)... I'm guessing my best bet is to buy an angle meter and go from there.
Yeah, get yourself an angle meter and measure. I pull the drive shafts and measure across the machined face of the yokes. The pinion should be 1 degree lower than the T/C output. That is the way it is from the factory, at least according to my 1980 FSM. Ditch the aluminum shims. If you need to use shims, use steel ones that bolt to the springs with the center bolt as skiriz said. I've seen aluminum break.
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