NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old May 2nd, 2022, 15:55
markaboo929's Avatar
markaboo929 markaboo929 is offline
NAXJA Forum User
 
Join Date: Aug 2003
Location: Mooresville,NC
Posts: 1,161
96 XJ AW4 buzzing

Hello I have a 1996 XJ with an AW4 4 x 4 transmission. I get a buzzing sound underneath from the torque converter / pump area when it is cold. Intermittently the transmission seems that as it warms up that it's not shifting as crisp as it does when it's cold mostly when it kicks into overdrive it seems like it's slipping a tiny bit. I almost have a feeling it's the pump but not exactly to be sure I have not heard a buzzing sound out of this out of any automatics that I have encountered GM Transmissions anyways. Here is a video of the sound to see if anybody has experienced if a pump or torque converter is the issue.
https://youtu.be/dB0Lq3dbEOg
Reply With Quote
  #2  
Old May 13th, 2022, 07:16
Unclewolverine Unclewolverine is offline
NAXJA Forum User
 
Join Date: Jun 2019
Location: Kansas
Posts: 749
Re: 96 XJ AW4 buzzing

I wish someone knew what this was because mine has been doing this for months. Yesterday twice after I came off the highway it acted like it was slipping and having trouble shifting but went away after I shut it down for a few minutes. On my way home it actually started squeaking like the belt but from under the jeep. I haven't serviced it in the 85k since I put it in so I'm going to service it when I get back from vacation monday, but it already had supposedly 100k on it when I put it in so it may just be done. Postal miles are hard on parts.
Reply With Quote
  #3  
Old May 13th, 2022, 09:51
markaboo929's Avatar
markaboo929 markaboo929 is offline
NAXJA Forum User
 
Join Date: Aug 2003
Location: Mooresville,NC
Posts: 1,161
Re: 96 XJ AW4 buzzing

I believe it is the pump. If ya think about it the sound is similar to a ps pump low on fluid.
I have a feeling that when it happens the clearance between the gears get excessive and cavitate fluid and lose pressure. The correct way would be to drive it with a pressure gauge attached. And what would explain is when you shut it off the gears relax and sort of reset their position and then everything is fine again. I have experience rebuilding GM automatic and never had this issue with any pumps on those.
I am going to receive a another transmission and rebuild that one. I do have a two-wheel drive transmission that was working fine when I upgraded to two-wheel drive to four-wheel drive. I just might swap out the pump on mine currently in use and see if that cures it and if it does this will confirm auspicious
Reply With Quote
  #4  
Old May 13th, 2022, 10:26
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 15,761
Re: 96 XJ AW4 buzzing

I wouldn't change out the pump unless you are really desperate as the are so many bearings/bushings that exist right at that connection point of the torque converter!
Reply With Quote
  #5  
Old May 16th, 2022, 19:11
Unclewolverine Unclewolverine is offline
NAXJA Forum User
 
Join Date: Jun 2019
Location: Kansas
Posts: 749
Re: 96 XJ AW4 buzzing

Update on mine: back from vacation, bought a filter, some valvoline max life and dropped the pan. After 85k postal miles there was hardly anything on the magnets and only a fine, thin film on the pan; but the filter screen looked completely clogged with the fine particles! Cleaned up and put it back together with the new filter, shifts just fine and no pump whine. The real test will be the next time I work, but tomorrow I'm putting in a new set of rod bearings.
Reply With Quote
  #6  
Old July 1st, 2022, 17:07
markaboo929's Avatar
markaboo929 markaboo929 is offline
NAXJA Forum User
 
Join Date: Aug 2003
Location: Mooresville,NC
Posts: 1,161
Re: 96 XJ AW4 buzzing

I did some internet searching on the A340 x Series E H F and so forth. I stumbled upon a Lexus Forum which has the A340 and there was a video posting the exact same noise mine was doing. What I ended up doing was dropping the pan and looking at the screen and sure enough it was kind of like a blackish type substance. The pan had the same type of a film on it too. I had the pan off about 8 months maybe ago ti replace the solenoids and used Valvoline de/merc II,III fluid.So I replaced the screen filter and this time as from the Lexus Forum I decided to use the Toyota T-IV fluid.I know what ya all are thinking dex III only.However the lexus forum all swore by that fluid.After all the AW4 is a Toyota Aisin unit.The pump was starving for fluid causing the noise and not enough volume/pressure to keep the clutch packs together. The trans shifrs like new I am very happy with the outcome!
Next time your AW4 buzzes I would change the screen first before thinking the pump is bad.
Reply With Quote
  #7  
Old July 1st, 2022, 18:33
Unclewolverine Unclewolverine is offline
NAXJA Forum User
 
Join Date: Jun 2019
Location: Kansas
Posts: 749
Re: 96 XJ AW4 buzzing

Update on mine. It still dosent make any noise but the slow going into 2nd when cold is back and slightly worse. It still works great until I let it set for 10 minutes then it acts up for a mile again. Not enough of an issue yet to warrant me tearing into it. A tranny guy I asked said it probably wasn't electrical, either a spool valve hanging up or valve in the body is hanging up.
Reply With Quote
  #8  
Old July 2nd, 2022, 07:30
markaboo929's Avatar
markaboo929 markaboo929 is offline
NAXJA Forum User
 
Join Date: Aug 2003
Location: Mooresville,NC
Posts: 1,161
Re: 96 XJ AW4 buzzing

Quote:
Originally Posted by Unclewolverine View Post
. A tranny guy.
Are you sure he was a guy?
Reply With Quote
  #9  
Old July 2nd, 2022, 09:54
Unclewolverine Unclewolverine is offline
NAXJA Forum User
 
Join Date: Jun 2019
Location: Kansas
Posts: 749
Re: 96 XJ AW4 buzzing

Don't care, as a long the advice/ work is good I could care less about anyones anatomy or preferences, lol.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AW4 Buzzing cold markaboo929 OEM Tech Discussion 0 April 6th, 2022 09:39
Buzzing Noise IRN GYNT OEM Tech Discussion 4 April 30th, 2017 18:23
'98 XJ Buzzing Under Dash fubar XJ OEM Tech Discussion 5 December 22nd, 2009 11:03
Buzzing, what is this? (91 XJ 4.0l) gregmondro OEM Tech Discussion 6 February 23rd, 2008 14:51
Quit buzzing sloppyjoe OEM Tech Discussion 9 February 16th, 2005 21:57


All times are GMT -7. The time now is 23:18.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014