85 cj7 rear end noise - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > CJ Jeep Forum > CJ Tech Forum

Join Wrangler Forum Today

Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 02-04-2015, 06:05 PM
Thread Starter
Join Date: Jan 2015
Posts: 5
85 cj7 rear end noise

Hello, I have an 85 cj7 with 4.2 and 4spd t176 trans . When I driving and if I let push the clutch in to coast/slow down I get a nice humming noise from my rear end pretty sure it's a bearing but my question would be which is most likely the culprit? It happens in gear clutch in or when I'm in neutral. Thanks for the replies.

ghelpling is offline   Quote
Old 02-06-2015, 05:30 PM   #2

::WF Administrator::
4Jeepn's Avatar
Join Date: Apr 2005
Location: Florence, KY
Posts: 12,272
Not sure what to tell ya, i will assume it a model 20. I would guess and this is a big guess its doing it in neutral the pinon bearing... but not sure..

also are you sure its not just the a clutch issue?


JKU Build Inside: Party Girl
WranglerForum: Youtube Channel https://www.youtube.com/channel/UCHO...TLdAuMbTLs_bxw

JKUR 2" Rancho Sport - BlackForest Throwback Top - Milestar 315 Patagona Mt's - Outlaw Sheriff Rims - Bushwacker Flat Fenders -
Spicer Parts F/R Diff Covers, Front Drive Shaft - 4340 Alloy Shafts- Metal Cloak Overland Rock w/Flip Step -JCR Transmission Skid- Quadratec LED Headlights- Q9500i winch
4Jeepn is offline   Quote
Old 02-12-2015, 05:52 PM
Thread Starter
Join Date: Jan 2015
Posts: 5
Yea it does it if I just let off the gas and don't touch the clutch, if I push in the clutch , and if I shift into neutral and let the clutch out the only difference is when I put I take it out of gear I don't hear it transfer through the driveline and can only hear it in the rear end...
ghelpling is offline   Quote
Sponsored Links
Old 02-12-2015, 07:45 PM   #4
getoffmyleg's Avatar
Join Date: Oct 2013
Location: Spring City, Pa
Posts: 497
Have you checked your U joints? One may be going but not have enough play to start clunking when you go on or off throttle.
getoffmyleg is offline   Quote
Old 02-13-2015, 02:49 AM
Thread Starter
Join Date: Jan 2015
Posts: 5
I hadn't thought too once I just got a brand new drive shaft with new spicer u joints.
ghelpling is offline   Quote
Old 02-14-2015, 08:41 AM   #6
Mowrangler's Avatar
Join Date: Jun 2013
Location: Tampa Fl.
Posts: 1,727
Probably pinion bearings so you might as well do the carrier bearings and axle bearings while you are in there.
95 YJ 2.5 5 speed 33" Mud Rovers SOA
A frustrating WORK IN PROGRESS
Mowrangler is offline   Quote
Old 03-24-2015, 12:23 PM   #7
Join Date: Mar 2015
Location: Ventura Ca
Posts: 28
I went through this same problem , did you change your lift ?if you did i would bet it's a drive line vibration due to an increased angle, when there is no load on the drive line it ls able to rattle a bit, add a load and it stops . a bad rear end would always make a grinding or squeal sound .
J P is offline   Quote
Old 03-26-2015, 02:49 PM   #8
duffer's Avatar
Join Date: Oct 2012
Location: Bozeman, MT
Posts: 218
Rear axle noise on deceleration is almost always a bad pinion bearing or really bad preload. The slack lets the pinion go rearward too far. The first question I would have is if the yoke was changed out with the driveshaft replacement? That axle uses a crush sleeve and once used it should be replaced to get the proper bearing preload with a new yoke.

1947 CJ 2A, 1949 CJ 3A, 1955 CJ 3B, 1968 CJ 5, 2012 JKUR
duffer is offline   Quote

Thread Tools

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 Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 06:17 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

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