breaking wobble

[rifle6]

i just got the rear 2 inch lift on the xj. (not fun)

anyway i have a wobble when i hit the breaks, i can also feel it in the peddle,

do i need axle shims or is this some thing else?

lift is rubicon express add a leaf and new shocks rear.

 

[grandmaster]

Well is it driveline vibes?

 

[NoTrax]

Well is it driveline vibes?

I would not think its a driveline vibe if its only on braking, i would think that it would be along the lines of ball joints, or shim spacing, or the axle rotated a bit in the rear, bad spring pack? I would almost count out driveline being the culprit

 

[Milner]

Before anything else, set it to 1/8" toe in and test drive.

 

[rifle6]

thanks for the input

i'll go into more detail now, when i posted this ii was on "break"

before the lift the xj drove great 0-80 no wobble. stopped great no wobble.

installed add a leaf in rear, new rubicon express shocks.

test drove. no wobble at all in acceleration 0-50 mph.
extream wobble during breaking, that gets worse the harder you push. then goes away completely if you let of the brake.

so i put the front lift on , 2 inch spacer, new shocks, rides great sits about where i wanted it, (maybe a bit low) but oh well.

after test driving it with all the lift on, the wobble is still there , no change.

i did not think a 2 inch would change anything with the drive angles. it is probably not much higher than when it was new.

my thoughts.
1. it did fall about 3 inches to the cement and landed on the drum, but i have hit them harder than that trying to get them off before on other trucks so i don't really thing that is it.
2. after tightening everything on the rear and putting the wheesl on and letting it down i did remember that in the instructions i read DON'T TIGHTEN THE SPRING EYE BOLTS UNTIL THE WHEELS ARE ON THE GROUND.

i did not follow that...... so is that a possibility?

as far as front alignment goes,, i had not messed with that yet so i don't think it is up there.

axle alignment, shim spacing? there were no shims in it before,
but i put the spring bolt into the ubolt plate hole, and the other side into the hole on the axle.

is there more to aligning an axle that that? 1st one for me so that is a possibility

it does look like the axle shaft is straight and level it looks like it needs to rotate up just a scoush but i don't remember how it looked before.

and is it possible to rotate it without shims?

sorry for all the dumb questions, i'm a lift rookie.

thanks again

 

[NoTrax]

Wow, there are so many things you listed in that last post that could be it :-\

 

[rifle6]

LOL.
thats alot of help!

 

[Milner]

XJ has inverted y steering linkage. It did change the alignment when you put the lift on.

 

[JackKeslerCustoms]

My first guess when you posted up was that your leaf packs were loose, either center pin or U-bolts. But after thinking bout it for a minute it sems odd to me that the rear drums would pull that hard to cause a violent wobble. (Don't the disks on the front do 70% of the work?) But if you did unpack and re-pack the springs, My gut feeling would be to start there. Just jack it up, pull off the U-bolts and re tighten the center pins, make surre the clamps are tight front and back to keep them from twisting. Then you may want to check the E-brake. If you did not relocate the bracket and it's pulling on the line, that might be causing friction and heat in there if it's not completely disengaging, but I don't know if that could cause a wobble. I don't know honestly if either of these wil fix your problem, but taking care of both is probably a pretty good idea.

 

[JackKeslerCustoms]

XJ has inverted y steering linkage. It did change the alignment when you put the lift on.

Very good point.

 

[rifle6]

i agree with the spring pack idea,
i broke one bolt tightening it so i did not go as tight on the next two, the springs appeared to be metal to metal then i went to the specified 20 ft lbs.

i destroyed one spring clamp per side there are still 3 and they appear to be aligned i need to get two new ones, but there is still near the middle and one on each end.

the ebrake cable seems to have enough play

i will check the spring pack bolt right now,

question, will lifting the back change the front end alignment?

thanks again

 

[XJEEPER]

If your AAL springs are bolted to the stock springs properly, with the centering pin in the alignment hole and the ubolts properly torqued, there isn't much more to address in the rear.

As Mark stated, 2" of lift will effect your steering geometry. You will need to adjust your toe-in to 1/8" and then center your steering wheel. If your toe in is out of spec, you will get a wobble when braking, or even worse, at freeway speeds.......ever hear of Death Wobble?

http://www.go.jeep-xj.info/HowtoAlignment.htm

Keep in mind that Marcus is in Australia, so everything on his XJ is on the opposite side in regards to steering components, but the same tech applies to US models.

 

[rifle6]

ok
i'll look into the toe in.

i was hopeing that would not be it
i know zero about toe,canter ext.

thanks

 

[Milner]

question, will lifting the back change the front end alignment?

It shouldn't, but if it the alignment was on the edge prior to the lift, the weight transfer forward of rear being higher could squat the front enough to push it over the edge.

I have dealt with DW on many XJ's and you are fighting a loosing battle if you don't align it first! XJ's are more hyper critical on toe then ANY other vehicle I have worked on. Makes no sense, but it have seen it over and over.

That being said DW is almost always many small things, not one big one....

 

[rifle6]

well, i finally got some time to look into the drum, i jacked it up the right side turned freely, the drivers side was bound TIGHT.

i pulled the drum and on the inside of where i hit the outside was rainbow colored, extream heat at work.

30 bucks and and a new drum later...SMOOTH BRAKING!!
that was it, just goes to show how a little hammer work might not be the way to go.

thanks for all the input and help.

 

[XJEEPER]

Glad it was an easy fix, good case made for jackstands. Btw.....did you ever check out your alignment? Hate to have a worn out set of tires be the heads up......

 

[rifle6]

ya it needs alignment i'm sure, it has a slight wobble that i would normally associate with front end, when i get the new set of black wheels and tires it will get alignment then.

maybe i described the feeling/sound wrong in the initial wobble, it was HORRID shaking and LOUD. when braking, ........hindsight.

i'm glad it was an easy fix, i was sick to think that i was going to have to pull the leafs off again, it sucked, but i guess it would be easier than the 1st time,