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  AOD Trans problem - clunking

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Author Topic:   AOD Trans problem - clunking
joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-09-2004 05:36 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
Hello everybody. Could use some advice. My 90 GT 5.0 with an AOD, While I'm driving and just as I let off the gas at any given speed somehwere in the driveline there is a clunking. Sometimes happens when I give the car gas as well. It's a pretty dramatic clunk, enough that you can feel it in the pedal, and in the seat. My motor mounts are a bit cracked but by no means broken and I visually inspected the u joints and they apear to be fine. Could this be my throttle linkage or shift linkage? Advice apreciated.

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SteveLaRiviere
Administrator

Posts: 43395
From: Saco, Maine
Registered: May 99

posted 07-09-2004 06:43 PM     Click Here to See the Profile for SteveLaRiviere   Click Here to Email SteveLaRiviere     Edit/Delete Message   Reply w/Quote
Have you checked your transmission mount?

Does the sound pitch of the rear change as you go from acceleration to coast or decelleration?

------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-09-2004 06:48 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
I have a new Trans mount I'm going to install tonight, will see if that addresses the problem. Are you asking if it makes the same noise when I decelerate? It does. It's like a clunk. Happens when I accelerate or decellrate. If I try and give the gas really smoothly for an easier shift I can sometime keep the sound from happening but if I'm in traffic and making lots of accleration and decelration it happens mostly then.

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SteveLaRiviere
Administrator

Posts: 43395
From: Saco, Maine
Registered: May 99

posted 07-09-2004 06:59 PM     Click Here to See the Profile for SteveLaRiviere   Click Here to Email SteveLaRiviere     Edit/Delete Message   Reply w/Quote
Well, you said your u-joints are ok. I would next check the backlash of the ring and pinion in the rear end. A quick and dirty way is to get both rear wheels off the ground, {on jack stands, of course} put the emergency brake on and twist the yoke at the rear. If it's real sloppy, there's the source of your noise.

------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-09-2004 07:09 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
ok, I'll try that tonight when I have the car up in the air. You wouldn;t think it's something like a torque converter going bad, or loose flexplate or the likes would you? Outside of that noise the hifting works great, and engine is tip top. I figure it might be bad motor mounts too, not certain though. The rubber is cracked some but by no means broken. I just hope it's not something terrible like a tranny going south. I'm also going to check the TV cable and linkage. Thanks for the feedback.

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SteveLaRiviere
Administrator

Posts: 43395
From: Saco, Maine
Registered: May 99

posted 07-09-2004 07:28 PM     Click Here to See the Profile for SteveLaRiviere   Click Here to Email SteveLaRiviere     Edit/Delete Message   Reply w/Quote
Torque convertors going bad usually just start slipping and you mentioned it shifts fine. Broken flexplates make noise all the time, generally.

------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-09-2004 07:31 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
Ok, wwell that's a good thought anyhow. Would hate to have to get into that right now. I'll check all the things mentioend though and see what ahppens. You know I only looked at the u joints and didn't really have a good grip on the shaft so I'll change those just because. I think I'll change the tranny fluid as well since I don;t know when the last time it was changed was. Thanks again!

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SteveLaRiviere
Administrator

Posts: 43395
From: Saco, Maine
Registered: May 99

posted 07-09-2004 07:38 PM     Click Here to See the Profile for SteveLaRiviere   Click Here to Email SteveLaRiviere     Edit/Delete Message   Reply w/Quote
If you're careful, you can take the u-joints apart and inspect and clean them then reassemble them.

------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-13-2004 01:56 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
An update on the problem:

So I serviced the rear end, used Mobile 1 synthetic and 4oz friction modifier. Changed the U joints F/R. Serviced the transmition with new filter, and Mercon V. I still have yet to change the motor mounts, or trans mount but plan on doing that in the next 2 weeks when I find time.

Now, when driving the car, the rear end is really quiet, no whine. The transmition shifts perfect from idle, 1st to second is nice, 2nd to 3rd is nice, 3rd to 4th is the clunker. If I'm driving as smoothly as possible and not getting on it the transistion from 3rd to 4th is not as bad. It when I manipulate it by either letting off the gas when the shift is occuring, or on and off the gas in 4th, or overdrive. I really am not sure. Wondering if it is the mounts at this point. The tranny fluid looked fine and the rearend fluid was decent.

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 07-14-2004 12:18 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
I'll check that. I checked and adjusted the cable at the throttle body but have not checked it out at the trans side yet. Somebody else suggested that same thing.

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BorgMoose7of9
Journeyman

Posts: 36
From: Aloha, Oregon, 97006
Registered: Apr 2003

posted 07-15-2004 02:53 PM     Click Here to See the Profile for BorgMoose7of9     Edit/Delete Message   Reply w/Quote
Actually, there is another problem all together.
The AOD has a problem with breaking the inner input shaft(there are two...the inner and outer...the outer runs 1/2 and R, and the inner runs 3 and O/D)....with the stock valve body. What you are feeling is a bind, then a pop, as the tranny is binding up due to the stock crappy valve body causing shift overlap(3rd gear is not fully disengaged when O/D is engaged). Install a trans-go SK **** improver kit for a good improvement(it should stop it), or the Transgo AOD-HP or Baumann AOD shift kit to further improve shifting.

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 09-10-2004 12:40 AM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
Well, got around to installing the transgo AOD-HP kit and the shifting is really nice and firm. Had to do it twice becuase I broke the rubber seal on the 3rd accumulator piston and caused a massive line pressure loss. Drove the car down the road and slipped first from idle, was able to overcome this for testing reasons by adjusting the TV position way in. anyhow, got that all back together. Now, I still have a clunk coming out of OD, mostly when the car is hot and under load (up hills). not sure..

I want to do new gears soon but need to save some coin. Anybody know of a good shop in southern california for a gear install? I am amfraid to do it myself and don't even have the proper tools. I was thinking 3.73's but don't want to burn ouy my OD. thoughts? Thanks.

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BorgMoose7of9
Journeyman

Posts: 36
From: Aloha, Oregon, 97006
Registered: Apr 2003

posted 09-12-2004 04:02 AM     Click Here to See the Profile for BorgMoose7of9     Edit/Delete Message   Reply w/Quote
Is it clunking when going INTO O/D? Or is there a steady clunk?

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 09-13-2004 11:34 AM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
Yeah, it has to be to right set of circumstances, but I think it's when the RPMs happen to be dropping rapidly while going into OD. If I'm on it a little extra, and let off just before it shifts into OD. Does that make sense?

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BLUE
Gearhead

Posts: 173
From: COLLINSVILLE, IL
Registered: May 2002

posted 09-13-2004 12:45 PM     Click Here to See the Profile for BLUE     Edit/Delete Message   Reply w/Quote
my 90 does the same thing. kinda like it is stuck between which gear to go to, stay in third or go into o/d. but like you said only when you are getting on it then let off right before it shifts into o\d. i dont think there is anything wrong with it. just my opinion!

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joer
Gearhead

Posts: 153
From: Westminster, California, USA
Registered: Aug 99

posted 09-13-2004 12:49 PM     Click Here to See the Profile for joer   Click Here to Email joer     Edit/Delete Message   Reply w/Quote
I'll jsut take it easy on it I guess. You know, I think happens more often when it's hot, after driving for a while. I'm installing a FRPP Trans cooler this weekend.

Side question: Would installing the AOD-HP Transgo kit decrease my gas mileage?

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