NO OD on AOD
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Mountain Pass
Joined: Nov 2001
Posts: 153
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From: Caldwell, KS
NO OD on AOD
Having a problem with a 91 with a 302 and AOD. If I put it in the overdive position I can start out and go from first to second to third, but when it goes to OD its just like its in meutral. This started all of a sudden and i haven't fooled with anything. I tried changing fluid and filter hoping that would help but it has not. Once it acts like its in neutral I can selct the drive position and it engages again, but if you go back to OD its like neutral again. So only OD is not working. Is the OD clutch pack seperate? or is there a common problem area related to the OD that might suggest a fix? All the other gears are solid and the fuild seemed fine when it was changed, not metal in the pan or filter and the fluid wasn't burnt. The motor is an EFI
Senior User
Joined: Dec 2001
Posts: 111
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From: Chico USA
NO OD on AOD
When you changed the fluid and checked the pan was there a black almost slime like build up on the magnet? Or is the fluid a darker red than usual? You could also smell the fluid to see if it is burnt. From your description it sounds like your overdrive clutch pack is done for. My second gear clutch pack on my E40D just went and my tranny had the exact same syptoms as yours for second gear. Plus my tranny fluid was a little darker than usual and smelled burnt. Then I checked the tranny pan and there was that black build up I refered to. A local tranny shop said that means the clutches are going or are gone. That sounds like a rebuild, although I am no expert. If you do the rebuild make sure to get all of the upgrades to your AOD. I went to www.baumannengineering.com and found a ton of info on AODs, you may be interested. They also stated that "Because of its small diameter, the direct clutch is a weak link in these transmissions (especially the old AOD)." Good luck.
Alex
Alex
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,722
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From: SE Florida
NO OD on AOD
The overdrive band or servo failed. You can probably drive for quite a while if you keep it out of overdrive.
It might not be too expensive to fix if you find a good shop to do it. When these fail they usually don't take much of anything else with them.
Mark
It might not be too expensive to fix if you find a good shop to do it. When these fail they usually don't take much of anything else with them.
Mark
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Mountain Pass
Joined: Nov 2001
Posts: 153
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From: Caldwell, KS
NO OD on AOD
OK so if its the band or servo, can they be replaced in the vehcile? I understand that the servo requires removing the valve body, what about the band. I'm willing to try it myself if I have some what of an idea of what to expect. I have all the ford part numbers related to the servo, found those in regqards to the upgrades. If anyone can get me the neccessary basic instruct on how this repair might go I would appriciate it.
Senior User
Joined: Oct 2000
Posts: 102
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NO OD on AOD
THe overdrive servo can be replaced with the tranny in the vehicle, but not the band, which is more likely to be the problem. To get to the servo you must remove the pan and the valve body. If you have a dial indicator and in inch pound torque wrench, you can probably get the overdrive servo tool from a tranny shop and check your servo travel to see if it is within specifications.
