Rear End Vibration - JeepForum.com
 
LinkBack Thread Tools
post #1 of 10 Old 10-17-2011, 10:24 PM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
Rear End Vibration

I have a 99 sahara that i just replaced the frame on. the reason for the frame replacement was because of the amount of rot on the original frame. the rear upper control arms (both) rotted completely off and may have messed up my rear diff. i have a dana 35 in the rear. when i accelerate, i feel an unusual vibration from the rear end. the jeep is lifted 2.5 inches and the transmission skid is lowered about an inch. i cannot figure out the source of the vibrations. they only occur at around 1800 RPMs and 2800 RPMs. i figured the frame swap would fix the problem but it still occurs. prior to the frame replacement, i pulled the rear diff cover and noticed a lot of metallic sheen in the fluid and some sand grain sized metal shavings in the bottom. i cleaned the diff and filled with new fluid to try to see if that would help. it didnt. while i had the diff cover off, i also noticed that one of the teeth on the Ring was slightly chipped but only saw one tooth that seemed to be damage.

any ideas on how to fix this? or what may be the cause of the vibrations?

nickrad8 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 10-17-2011, 11:06 PM
RaggedOleMan
Registered User
2005 TJ Wrangler 
 
Join Date: Jul 2007
Posts: 2,353
Quote:
Originally Posted by nickrad8 View Post
I have a 99 sahara that i just replaced the frame on. the reason for the frame replacement was because of the amount of rot on the original frame. the rear upper control arms (both) rotted completely off and may have messed up my rear diff. i have a dana 35 in the rear. when i accelerate, i feel an unusual vibration from the rear end. the jeep is lifted 2.5 inches and the transmission skid is lowered about an inch. i cannot figure out the source of the vibrations. they only occur at around 1800 RPMs and 2800 RPMs. i figured the frame swap would fix the problem but it still occurs. prior to the frame replacement, i pulled the rear diff cover and noticed a lot of metallic sheen in the fluid and some sand grain sized metal shavings in the bottom. i cleaned the diff and filled with new fluid to try to see if that would help. it didnt. while i had the diff cover off, i also noticed that one of the teeth on the Ring was slightly chipped but only saw one tooth that seemed to be damage.

any ideas on how to fix this? or what may be the cause of the vibrations?
Get down on your knees & view the angle/relationship of the drive shaft to the pinion from the side of your rig. They need to be "inline" with each other. In other words, there should be little to no angular change between the pinion & the drive shaft at the u-joint while at ride height.
RaggedOleMan is offline  
post #3 of 10 Old 10-18-2011, 10:43 AM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
so in other words where the rear diff meets the u-joint should be level with the ground and same thing where the transmission meets the u-joint? im not sure if i said that right.
nickrad8 is offline  
post #4 of 10 Old 10-18-2011, 11:54 AM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
do you know what angle the drive shaft should be at? and could it be the bearings in the differential? or would that cause a constant vibration at every speed/RPM?
nickrad8 is offline  
post #5 of 10 Old 10-18-2011, 12:46 PM
RaggedOleMan
Registered User
2005 TJ Wrangler 
 
Join Date: Jul 2007
Posts: 2,353
Quote:
Originally Posted by nickrad8 View Post
so in other words where the rear diff meets the u-joint should be level with the ground and same thing where the transmission meets the u-joint? im not sure if i said that right.
No...not level with the ground...

The u-joints on the end(s) of your DS allow for angularity between the DS & pinion as the axle & suspension cycles. However, while at ride height there should be little to no angulation between the pinion & the DS, while there may be some at the TC end. Also, do you have a slip yoke or SYE & CV DS, I forgot to double check your profile...?

If you don't have a clue what I'm talking about, I strongly encourage you to visit with a competent mechanic familiar with 4wd vehicles in your area. Or someone that's better at expressing themselves in print than I am. Good luck.

EDIT; You have to fill in your profile to get competent help...
RaggedOleMan is offline  
post #6 of 10 Old 10-18-2011, 01:38 PM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
I don't believe I have an SYE I will check when I get home tonight. I will also upload a picture for you. I just looked at the FSM to see if I could find a picture of what you were talking about and I think I understand what you are saying. When the jeep is parked, the driveshaft should look like it is a solid extension from the rear end as if there was no u joint between the rear diff and drive shaft. I don't think I have a CV drive shaft either. I apologize for not having my profile filled out. I forgot to do it
nickrad8 is offline  
post #7 of 10 Old 10-18-2011, 05:52 PM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
I figured out the issue. I forgot to install the transmission skid plate spacer. Thanks for the help
nickrad8 is offline  
post #8 of 10 Old 10-18-2011, 07:11 PM
NakedCreekTJ
Registered User
1998 TJ Wrangler 
 
Join Date: Aug 2011
Location: Elkton
Posts: 134
okay so im having a similar issue. while in 3rd gear and accelerating, my jeep vibrates like its a race car or something. haha, but in all seriousness is this something i should be concerned with? the jeep has a 2.5" lift and only has 30" tires. Also, im almost certain it has spacers on the skid plate...

___ ___
[l_,[____],
l---L - OllllllO-
( )_) ( )_)--)_)
NakedCreekTJ is offline  
post #9 of 10 Old 10-18-2011, 09:42 PM Thread Starter
nickrad8
Registered User
 
Join Date: Sep 2011
Location: manchester
Posts: 19
does it happen while accelerating at any speed in third gear?
nickrad8 is offline  
post #10 of 10 Old 10-19-2011, 10:29 AM
NakedCreekTJ
Registered User
1998 TJ Wrangler 
 
Join Date: Aug 2011
Location: Elkton
Posts: 134
Yea from what I've noticed it does.

___ ___
[l_,[____],
l---L - OllllllO-
( )_) ( )_)--)_)
NakedCreekTJ is offline  
Reply

Tags
differential , rear end , tj , vibes , vibration

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
vibration in the rear at 65+ mph Yamahafreak93 YJ Wrangler Technical Forum 2 07-09-2011 11:53 AM
vibration from rear...? epeck87 TJ Wrangler Technical Forum 9 12-31-2009 04:49 AM
Rear end vibration florida_gat0r TJ Wrangler Technical Forum 8 07-25-2008 10:04 PM
help vibration in rear end catdaddy06 TJ Wrangler Technical Forum 8 04-04-2008 02:26 PM
Rear Vibration? nightstalker5.0 YJ Wrangler Technical Forum 10 01-09-2005 05:03 AM

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
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome