Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum > Need help with rear drive line vibes.

Join Wrangler Forum Today


Thread: Need help with rear drive line vibes. Reply to Thread
Title:
  
Message:
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-30-2013 10:18 AM
All Terrain JK Update: I had the drive line shop recheck the DS, they said it was all good. I reinstalled the DS and set the PA at .5° down. The change doesn't rattle anymore but I still get some vibe at 25-30 mph accel and deccel. None on coast. It is felt through the seat and steering wheel. I don't think it's tires cause It doesn't vibe while coasting in neutral. I removed front DS and it is still there. Removed rear and vibes are gone. Could this have anything to do with the lowpro mount? I get a little more idle vibes with the LPM. Even though I'm confident it's not tires, I will have them rebalanced today. Thoughts or advise?
04-23-2013 02:32 PM
All Terrain JK So your telling me not to over-think it Jerry? Not many people can mountain climb a mole hill better than me lol. I'll set the ds and pa the same and test drive. Thanks
04-23-2013 01:21 PM
Jerry Bransford I would stop worrying about all those precise angle measurements your making, the only thing to worry about is getting the pinion shaft angle at the same angle as the driveshaft. So the pinion shaft points directly at the CV joint. Nothing else matters, not even the t-case output shaft angle.

The pinion shaft can point perhaps 1-2 degrees under that of the driveshaft but it can't point even 1 degree above the driveshaft.
04-23-2013 01:17 PM
All Terrain JK Thanks for the reply. I thought about that to which is why I removed the rear ds and and drove with the front. Drives smooth without rear ds.
04-23-2013 01:10 PM
n00g7 It seems odd to me that you have an off/on vibration problem at different speeds and are looking at the drive shaft. Do you know for a fact your wheels/tires are balanced, no play when mounted and your wheels aren't bent?
04-23-2013 12:31 PM
All Terrain JK I talked to the drive shaft tech and he said the ds is good to go. He also said the dc joint is rated at 26° max operating angle. With my tcase slope of 4° and ds angle at 23° my joint angle is 19°. Any thoughts or ideas?.
04-23-2013 07:09 AM
Patrick H The first thing I would do is what you're doing today. I've seen more than one newly rebuilt/ built drive shaft have issues, including from famous name drive shaft shops.
04-23-2013 06:29 AM
All Terrain JK
Need help with rear drive line vibes.

For those not familiar with my recent build my 98 had a 4" frankenlift with the stock skid and 1.25" drop. I replaced all arms with Savvy adjustables. I also installed: JBC SS SYE, UCF ultra high skid with lowpro mount, and a double cardan drive shaft. The tcase slope is 4° and ds is 19.75" long. I initially set ds and pinion angle at 22.5°.
The problem.
1st and 2nd are smooth, around 25mph I get a moderate vibe that slackeneds about 35. At 50 change in the console starts to rattle then stops at 70. This happens at acceleration, steady speed, and deceleration. If I shift into neutral at speed the vibes stop while I coast.
What I have tried.
I reduced the pa so the ds was 1° higher, 22° and 23° respectively. No change. I went to the drive line shop that built my ds and took a tech for a ride. He recommended dropping pa to 2° differential. Tried it and no change. I reset ds/pa to 23°/22° and removed the rear ds, it drives smooth as silk. I am having the ds rechecked today for any problems.
Thoughts or advice are welcome. Thanks

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -5. The time now is 06:58 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC