driveline vibes

[hoobness]

so the lift is on, its bouncy as hell, and I got driveline vibes at 40 and they get worse the faster i go.

This is about the vibes.

i know how common they are so Im not that worried, but I need to know if those vibes are from somehting wearing and eventually failing when I least expect and need it to fail,
OR
is it just an annoyance i can cruise around with and fix at my leisure?

BTW thanks for all your help over the last month as Ive been shopping and installing, needing advice etc...

 

[berettajeep]

RE: XJ Part Numbers needed

it is an annoyance that will fail when you need it most.

 

[hoobness]

Workin' on the heepin' jeepin'

great.

 

[GaryMB]

It will wear out your u-joints pretty fast. How big is the lift? Does the jeep have a t-case drop or wedges?

 

[hoobness]

RE: Workin

4" lift. I want to add 1" shackles too.
it has 4 degree shims and a 1" T case drop. The drivetrain has 220K miles on it.

I never noticed anything in the past. (no lift) --man it makes a noise now as I bounce on down the road!

So I should start making plans for a shaft and sye right?

 

[GaryMB]

Yeah, I've heard that wranglers need sye's with 4" lifts. Can't say if it'll help with vibes since I don't know much about them.

 

[Joopin]

RE: Bolts sheared off in frame!

CV Shaft and an SYE would work... $525 from Tom Woods for both.

 

[TwistedCU]

Re: RE: Buying a 1999 XJ ... Needing lift suggestions

Loosen the nuts underneath the transfer case skid plate that hold the transfer case to the skid(not the bolts that mount the skid to the frame). Drive moderately easy around the block, park on level ground and tighten. This will allow your transfer case bolts to re-seat in the slotted holes in the skid, while allowing it to settle into the new driveline angles. BDS suspensions reccommends this for their YJ kit and it removed all vibes on mine. I had a 3.5" lift with a 1/2" shackle lift (same height as yours).

Please let us know if it helps, I'm sure it will.

Total cost... $0.00

 

[Snitty]

SYE from ebay for about 200.. and get a TJ front shaft and have it cut down for about 100 or less

 

[hoobness]

i did what TC said about the 2 nuts in the center of the skid. they moved frontward about an inch, still got the vibes though. Mostly when accelerating. Im gonna make plans for the tom woods set up. read about it on jeepin.coms site last night.. hopefully itll wait til summer, ive been under it non stop for 10 days now doing various things in addition to the the lift... just want to enjoy it for a while.

had to fix an oil leak, ended up being the timing cover and front seal, harmonic balancer had a groove in it, replaced that-hopefully thatll end the leak. replaced the exhaust with a header, new cat, and cat back set up (sounds awesome) had to sandblast the header to paint it with por20, boy that was a pain in the a$$. And then there was the 30 hour lift job. Tonight i just finished putting on the extended flares. Aside from the tires i get next week, and the sye kit I inevitably need, i hope i wont be fixing it for a while. As much as i enjoy working on it, im burnt out, i want to rip up some new trails!

 

[Sparky-Watts]

i hope i wont be fixing it for a while.

Hang on to that dream! :lol:

 

[Bounty__Hunter]

RE: Gen Chat...please delete.

Not many YJ's have vibes at 4", and most all get away with a TC drop just fine. Double check your pinion angle and make sure it's parallel with the rear output of the transfer case. You may need a steeper axle shim. Also consider replacing the ujoints, as they're operating in a different range which can cause vibes.

 

[TwistedCU]

RE: what would you rather do?

shims on correctly? I know, you don't seem like the kind of guy to get that wrong, but I had to ask.

 

[hoobness]

shims are on with the fat end pointing forward, pointing the driveshaft up toward the T case. Never thought about steeper shims, where can I get some?

 

[LBR]

Have you checked the driveshaft for straightness? Put the rearend up on jacks, have a partner start and run the Jeep in 1st gear. Observe the runout from the side of the Jeep to verify shaft is indeed straight. LBR

 

[Sully]

Dont point the driveshaft toward the t-case unless it is a CV driveshaft. Like BH said, you should have your pinion parallel with the t-case output shaft. If you point it and it isnt a CV, you will experiance vibes for sure. If you still have vibes, I recomend the SYE and a CV driveshaft. Those will take the vibes away and you will no longer be annoyed.

 

[hoobness]

Im confused now about the vibes...

When you say parrallel you mean: The T case out is parrallel to the Input to the axle?

T Case Output >>>> drive
shaft <<<< Input to Axle

THE GROUND---------------------------------------------------THE GROUND

If thats the case I should remove the 4 degree shims that force the axle to point up a bit to the T case to then make the outut and input both parallel to the ground.

Am i complelty lost?

 

[Robrt-Stephens]

Re: Side visors for YJ?

so the lift is on, its bouncy as hell, and I got driveline vibes at 40 and they get worse the faster i go.

This is about the vibes.

i know how common they are so Im not that worried, but I need to know if those vibes are from somehting wearing and eventually failing when I least expect and need it to fail,
OR
is it just an annoyance i can cruise around with and fix at my leisure?

BTW thanks for all your help over the last month as Ive been shopping and installing, needing advice etc...

On VEX and the CJ-7 just before it, I had these problems with my lift installed and refused to accept it. So, I did two things:

I made my own 4 degree steel shims after seeing all the shims available were aluminium, which I knew over time would crush themselves into oblivion over time--especially the rear end, but no shims in front. So, I took a block of 3/4" steel that was 5" long and as wide as the springs and cut it diagonally, making two 4+ degree shims. I drilled a hole for the centering bolt and bolted them to my new Tuff Country springs. This tilted the rear diff upwards by 4-5 degrees.

Next, I went to a junk yard and found a 1 ton ford 350 4x4 and pulled the drivelines out of it and bought them for $20 each.

I took them to our local mahine shop and had them cut down for VEX and had them add a CV joint in both shafts, front and rear, at the transfercase.

This cured all DL prolems with the ARBs spinning up the OEM shafts into licorice and made VEX ride like a car, very smooth and no vibration at any speed ever.

A very pleasent ride on and off raod. And it has not changed for the last 13 years I've ran this setup save fr the Tuff Country lift probably needs to be updated with a RE 4.5" Extreme Duty lift.

I hope that helps, but I think that is the cure, at least it was for me.

 

[Robrt-Stephens]

Im confused now about the vibes...

When you say parrallel you mean: The T case out is parrallel to the Input to the axle?

T Case Output >>>> drive
shaft <<<< Input to Axle

THE GROUND---------------------------------------------------THE GROUND

If thats the case I should remove the 4 degree shims that force the axle to point up a bit to the T case to then make the outut and input both parallel to the ground.

Am i complelty lost?

First, everyone's response here is correct and I forgot to mention that on the YJs, yes, a SYE would probably be in order along with the suggested mods.

your explanation is accurate in statement but is in error in application. It is easier to and the CV jointsin the shafts front and rear at the T-Case.

Years ago, the 3/4 ton Fords 4x4 had the front diff pointd down and the rear up to keep all angles 0 degrees. But then they had 7 foot long DLs and those rigs weren't Jeeps.

A CV joint in both shafts really makes a tremendous difference. Unless you have the money for the TW driveline, I would go to the junk yard and get the 1 ton drivelines and save 100s on the cost of such. Bigger drivelines too as a result.

I later added two 1" thick steel bars along the bottom of the frame for a TC drop, but don't think this was needed after the better shims and CV joints and new shafts.

Just some more thoughts.

 

[Robrt-Stephens]

Dont point the driveshaft toward the t-case unless it is a CV driveshaft. Like BH said, you should have your pinion parallel with the t-case output shaft. If you point it and it isnt a CV, you will experiance vibes for sure. If you still have vibes, I recomend the SYE and a CV driveshaft. Those will take the vibes away and you will no longer be annoyed.

Hoobness,

Please note what Sully stated, "Without a CV joint, do not point the diff at the T-case". and he qualifies that with the fact you would need a CV joint and probably the SYE to do so.

This is correct. If you go the whole distance with the SYE and the CV joints in custom DL, that will fix the vibes.

Hope that helps.