Problems with take off on a 92 YJ

[rynozall]

This started after the lift and I can't narrow it down. Was hoping for some suggestions on what the problem might be. When I let out the clutch and give it some gas the jeep tries to bouce in the rear. It only does this when it’s been driven several miles. Sounds like something is loose in the back drive shaft but none of the u-joints seem to have excessive play. Does anyone have any ideas as this is getting annoying fast.

92 YJ
2 1/2 Pro Comp lift
31X10.50 Pro comp tires


Thanks in advance,

Rhy

 

[Bounty__Hunter]

Sounds like poor ujoint angles or not enough spline engagement in the slipyoke. Did you install a transfer case drop?

 

[rynozall]

Yes it is installed, came with the kit, rear shims also came with the kit and are installed.

 

[JJs 88 Wrangler]

Sounds like the drive shaft pitch is off.

 

[Bounty__Hunter]

Generally don't need the TC drop AND the shims, usually one or the other. That may be the problem. Make sure your two ujoint angles on the rear driveshaft are identical, meaning the same angle, then they will cancel vibration and work properly.

If possible, post a pic of the rear driveshaft along with both ends.

 

[Truth]

He has 2 methods of driveline correction and you guys think his angle is off? If that were so he'd get vibrations, not axle hop.

You better make sure those U-bolts are tight. I've seen this several times when people install their own lifts. The rear axle will wrap itself upwards accelerating from a stop.

 

[rynozall]

Will get some pictures tonight and will check torque the u bolt nuts. Anything else to check to stop the axle hop.

BTW I have no vibrations once moving just on take off. Had no idea there was a tech term for my problem. Axle hop describes it perfectly. Now to fix it.

Until tomorrow

Rhy

 

[buckshot500]

I have the stock suspension setup, but spring wrap is a big problem.
I am currently working on this project I saw on another board.

Here is a link to that build;
Cheap traction bar!!!!!

 

[rynozall]

Ok I checked the u bolts and all is with in spec so I took some pictures to show the angle of the drive shaft. Does everyone still believe its axle wrap? If so what is the cheapest fix? Will the traction bar that Buckshoot500 mentioned fix this?
BTW I do know that my seal is leaking just dont have time to pull it apart till winter.

 

[yj93ben]

Pinion angle is everything. After looking at your pictures I have to ask, was the leak there before the lift? If not, driveline vibration caused it. If this were my rig, the first thing I'd do is a slip yoke eliminator kit and a constant volocity driveline. This will lengthen your driveline for a better angle. YJs have tiny little drivelines. Generally, axle wrap or hop isn't a problem with spring under axle lift kits, unless you have 6" mono springs. I'm not saying it's impossible, just not probable. Skyjacker yj5lk is a nice traction bar, if you're leaning that direction. It's about $383 and requires minimal amount welding. SYE, CV driveline. Hope these sugestions help.

M.O.R.E. has a pretty nice one to, but requires a little more welding.

I'm not endorsing any of these stores. Just something to look at.

 

[cali_92]

srry i dont have any advice for ur problem
but how do u like that pro comp lift?
what socks did u get in the kit?

im looking at getting pro comps 4" lift kit
but idk which shocks to get. i'd rather save a couple hundred if its not a big difference.

good luck with ur problem. i'll probably have the same problem once i lift mine. ha

 

[roadking951]

looks like driveshaft is a couple inchs to short after the lift,look at wear pattern

 

[rynozall]

srry i dont have any advice for ur problem
but how do u like that pro comp lift?
what socks did u get in the kit?

im looking at getting pro comps 4" lift kit
but idk which shocks to get. i'd rather save a couple hundred if its not a big difference.

good luck with ur problem. i'll probably have the same problem once i lift mine. ha

I love the kit so far, have not had any problems except the axle hop, but I think it might have been there before as well. I got the standard 3000 shocks but wish I would have spent the money and upgraded. My brother has the same lift with the upgraded shocks and his is a lot smother of a ride. It would be worth it to upgrade. Still do not have a fix for the hop yet but I have other problems to deal with that I was told were more important that my toy. The dentist just installed 2 set of braces and now I have a payment on something I dont even get to own. Ha

 

[rynozall]

looks like driveshaft is a couple inchs to short after the lift,look at wear pattern

Can you explain to me what and where you see the wear?
Thanks

 

[bobcat481]

He sees it at the tail shaft where the slip yoke is...but it doesn't look like a couple inches to me. The bright metal is where the seal normally rode. The shaft is about 1-1/2 or 1 3/4. Compare shaft diameter to bright spot gives him about 1/2 - 3/4 shorter. Same as when I did my 4" lift. I had no problems with axle hop. Drive line angles bad enough to get wheel hop would be some EXTREME vibration and highway speeds. The angle coming off the pumpkin looks (from the pic) a little more than the angle at the slip yoke, but not enough to bind up in my opinion. I think he's got a different problem here. Why does it only do it after being driven for a couple of miles? I'm gonna take a wild guess here. Are you sure you got the alignment pins on the springs right? Maybe the u-bolts are tight but the springpack is not sandwiched down tight to the axle (alignment pins holding a gap) and your torqued right, but the spring pack is still loose. Still doesn't explain why it only does it after a few miles though. Good luck!

 

[rynozall]

It only happens when the Jeep is warm. I took it out yesterday and put about 100 miles one it, and I can not get it to happen even if I tried. So does it have something to do with the 100+ days we had this summer. Could it be the trans over heating? Or am I still looking at a drive line issue?

I did have problems getting the axle to seat down on the springs but it is all the way down and the u bolts are tight againt the axle and the spring. I could not get a piece of paper to go between the parts.

I do want to thank every one for all the help and suggestions. Keep them coming.

Rhy

 

[bobcat481]

Check your transmission fluid latley? Do you have any? What color is it?

 

[bobcat481]

My thought is the transmission is either jacked up or not. I wouldn't think it would just bind up all the sudden. You didn't happen to stretch your e-brake cable during the lift process? Brakes could be getting hot and binding up. Just a thought. Later

 

[carnuck]

E brake cable getting pulled and partially engaging? How old is the clutch? (down to brass rivets will act like that) Bigger tires too? (that affects the gear ratio) in 4x4?