Any Jeep Experts - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 04-16-2007, 07:23 PM
blackbeast
Guest
 
Posts: n/a
Smile Any Jeep Experts

I have a 1997 jeep TJ, i have a 4 inch suspension and a 3 inch body lift, with a 1 inch transmission case drop. its an automatic transmission, when i put my truck into reverse it vibrates heavily but when in all other gears it runs smooth.
Does anyone know what the problem could be? thanks
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 04-16-2007, 07:48 PM
Way Outta Control
 
Join Date: Sep 1999
Location: usa
Posts: 10,815
Thanks: 0
Thanked 1 Time in 1 Post
 
More info please -
When you first put it in reverse without moving, or when you let it move in reverse? Or both?

2 different problems.
RRich is offline  
post #3 of (permalink) Old 04-16-2007, 08:16 PM
blackbeast
Guest
 
Posts: n/a
Hey its both. i put it in reverse and it vibrates alot and even when im moving in reverse, but as soon as i put it in drive its fine the vibrating stops.
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 04-16-2007, 08:43 PM
Keyboard Implanted
 
Rio_Grande's Avatar
 
Join Date: Jun 2000
Location: Southeastern Indiana
Posts: 4,766
Thanks: 3
Thanked 2 Times in 2 Posts
 
I know with mine I could not get rid of the vibes until I added a 1" motor lift. Solved everything. I pulled my 1 inch trans drop and that helped even more. Yours may be something diffrent. With mine it was just the angles.

Ya only go around once, best to enjoy it the first trip.
Rio_Grande is offline  
post #5 of (permalink) Old 04-17-2007, 09:45 AM
I Might Just Know What I'm Talking About
 
JeepDawg's Avatar
 
Join Date: Dec 2006
Location: S. CA
Posts: 1,503
Thanks: 0
Thanked 0 Times in 0 Posts
 
Driveline Vibration.

I would be willing to bet that you also get 'some' vibration in forward under certain conditions.....

If you want to fix it right....dump the xfer case drop (never could understand why people raise the jeep and lower the xfer case)....buy a CV driveshaft...shim the rear axle so that it's pointing at the xfer case and be done with it....it will be the best $ you ever spent...

And get rid of the body lift...besides being unsafe (1" is ok), it rates high up there on the dork factor...

AKA DDawg16
84 CJ7, SOA, 5.7LTBI, 4L60E, 35"x12.5, 4.10 gears, F/Det, R/ARB, Full Roll Cage,
D44 Flat top in progress...
Link to my Frame up Restore
JeepDawg is offline  
post #6 of (permalink) Old 04-17-2007, 10:12 AM
Way Outta Control
 
Join Date: Sep 1999
Location: usa
Posts: 10,815
Thanks: 0
Thanked 1 Time in 1 Post
 
""""i put it in reverse and it vibrates alot and even when im moving in reverse, but as soon as i put it in drive its fine the vibrating stops.""""

OK - I think what you are saying is it vibrates/shakes when you are NOT moving, brakes still on etc. And it continues after you let it move in reverse.
Right?
I'll assume that's correct. And I'll have to assume your trans fluid is filled properly.

First off - a wrong driveline angle will NOT cause any vibration unless it's moving - the vibration comes from the U-joints binding or causing uneven rotation - but if they aren't turning (when you are stopped,) they don't do anything! They have to turn to cause trouble.

But - putting it in Reverse causes the engine to torque up a little, and in Reverse it has more leverage than in drive - due to the lower gear ratio in reverse, plus it's torquing in the opposite direction than in Drive.

I'd suspect you have a broken engine mount or trans/t-case mount, allowing it to "torque over" a little too much.
Or - the exhaust system is too close to the frame, hitting the frame or something when the engine torques over.

A broken mount or even the exhaust hitting may not be easily seen, unless you watch it while someone else (that you trust!) torques it over.

You might be able to tell if the mount is broken by putting a jack under the engine and/or trans and lifting the drivetrain a little - sometimes yes, sometimes no.
Try to determine whether is more of a noise than a mechanical vibration - sometimes it's hard to tell.

It's also possible it's an internal trans problem - low pressures causing shudder. Try holding the brake and raising the idle slightly - if the vibration stops it could be internal problems - have a reputable transmission shop take a look.

But first check the mounts!
RRich is offline  
post #7 of (permalink) Old 04-17-2007, 01:18 PM
Keyboard Implanted
 
thorjeep's Avatar
 
Join Date: Jan 2000
Location: In the process of finding it
Posts: 2,561
Thanks: 10
Thanked 1 Time in 1 Post
 
Good Call Rich, betcha you're right!

Scott
1985 CJ7 T.H.O.R

"He brought me up out of the pit of destruction, out of the miry clay, And He set my feet upon a rock making my footsteps firm."
-Psalm 40:2
thorjeep is offline  
post #8 of (permalink) Old 04-17-2007, 11:00 PM
Official Historian
 
WILL's Avatar
 
Join Date: Sep 1999
Location: Hot Springs, AR
Posts: 8,339
Thanks: 1
Thanked 5 Times in 5 Posts
 
I think Rich has it too with the engine torquing the opposite way.

"As the circle of my knowledge grows, so grows the circumference of the unknown." - Isaak Newton
WILL is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups 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 email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not 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 On
Pingbacks are On
Refbacks are On

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