AOD Issues, Need 2nd Opinion

Thomas A

Registered User
I am hoping to get some second opinions on my transmission issues before I replace it. I have a good trans ready to go in, but it doesn't have a torque converter. I would like to have a little piece of mind that my current converter is still good so I can reuse it before I install everything. The car is still very much drivable, and still shifts into all gears. However, it has the following issues, that seem to be getting worse:

Slips or free rev's in high rpm's instead of shifting. Have to let off gas before it shifts.
Doesn't like to shift into OD until you push it a little. One day it wouldn't shift into OD for a couple miles of 3K+ driving. Only did that once.
Occasionally flares on the downshift as you are coasting to a stop
Sometimes is sluggish to kick down, other times is fine
Occasionally harsher than normal 1-2 shift

When I first got the car, it was very slow on the WOT 1-2 shift, and felt like it was painfully slipping into the next gear. The trans was rebuilt before I bought it by Certified Transmission, and has about 30K on it.

So, internal trans issue, torque converter issue, external control issue, or a combination there of?
 
I think you should be able to find a local shop to inspect/flush the converter. I would at least do that before installing it in the other transmission.
 
I am hoping to get some second opinions on my transmission issues before I replace it. I have a good trans ready to go in, but it doesn't have a torque converter. I would like to have a little piece of mind that my current converter is still good so I can reuse it before I install everything. The car is still very much drivable, and still shifts into all gears. However, it has the following issues, that seem to be getting worse:

Slips or free rev's in high rpm's instead of shifting. Have to let off gas before it shifts.
Doesn't like to shift into OD until you push it a little. One day it wouldn't shift into OD for a couple miles of 3K+ driving. Only did that once.
Occasionally flares on the downshift as you are coasting to a stop
Sometimes is sluggish to kick down, other times is fine
Occasionally harsher than normal 1-2 shift

When I first got the car, it was very slow on the WOT 1-2 shift, and felt like it was painfully slipping into the next gear. The trans was rebuilt before I bought it by Certified Transmission, and has about 30K on it.

So, internal trans issue, torque converter issue, external control issue, or a combination there of?

My previous AOD SC's have done similar things when the filter and fluid needed to be cleaned. My base 3.8 w/ the AOD did the sluggish shifting and also searching when the filter was clogged up.

I'd always try fluid and filter first since its cheap and easy.

-Tim
 
I went ahead and pulled the trans today. The fluid smelled a little burnt, but didn't have any metallic sheen to it. It does appear that the converter is done for though :eek:

Trans_Swap6.JPG


Thomas
 
I don't "SEE" :cool:anything there that precludes reusing the converter. It does appear someone used flexplate bolts that weren't stock or the flexplate was defective. It appears that the converter snout was drawn too far into the crankshaft---no biggie there, I'd make my call on what the other side looked like, in particular the notches that fit into the oil pump drive.................Dan
 
I was under the impression that the bolt marks on the torque converter meant that it had ballooned. Is this true and does this mean there is an issue with the torque converter? Should one be used again once this has happened?
 
Should one be used again once this has happened?
If it was working when it was removed from the car, I don't see what the problem would be. I reused my TCs, as I recall they all had some minor marks from the crankshaft bolts. They've worked fine for more than 2 years now.
 
I was under the impression that the bolt marks on the torque converter meant that it had ballooned. Is this true and does this mean there is an issue with the torque converter? Should one be used again once this has happened?


According to Allan, apparently they ALL ballon. That is why his high po units have anti balloning plates welded on.

The converter is way to weak to handle the job. Mine had marks so deep in it from the flexplate bolts, that it looked like someone put them in with a dremel. Still in the car and running though. A more powerful motor and higher rpm's will definitely make it worse.
 
I just have two thoughts:

First, those symptoms sound strange. I am thinking they might be more related to valve-body issues.

Second, unless you have an expensive aftermarket converter, I might replace the thing. I mean, if you can do the removal & installation yourself, it might not be so bad. But I can't (don't have the facilities or any buddies to help), so I would rather pony up the $250 and know it's good.
 
Most likely the overdrive band is going. That is what the symptoms were on mine at first until the whole trans went. Both Allan and my local trans shop agreed on the symptoms.

If materials have start going through the oil,minimm tae Kurt suggestion and flush the converter. If it were me, I'm with Steve on installing a new one. Better safe than sorry.
 
I'm going the "better safe than sorry" and the "only want to do this once" route on this :)

I was going to be changing the transmission out with a good rebuilt one from my other SC anyway, and will be replacing the converter as well. I have a new unit with a billet face coming from Alan that will prevent further ballooning issues, while adding a bit of stall. I'm doing it all myself, so labor costs are not an issue.

Thomas
 
Good thoughts Thomas. Why take a potentially costly gamble for a few hundred bucks. Doing the labour yourself, your already saving a fortune.
 
If you are doing a performance rebuild or plan on adding some unusual power or buzz it up in rpm's definitely replace it with one that has a anti-balooning plate but for a stock rebuild for a daily driver ---I would throw that puppy in there, especially since you can do your own work..............Dan
 
Just a little follow up on this. I had this converter sitting there, and pulled the inner shaft from the transmission and inserted it into the converter. I was not able to turn it at all, so it seems that this converter was pretty close to locking up.

Thomas
 
Just a little follow up on this. I had this converter sitting there, and pulled the inner shaft from the transmission and inserted it into the converter. I was not able to turn it at all, so it seems that this converter was pretty close to locking up.

Thomas

The inner shaft on the AOD goes in to a damper that is connected directly to the cover, so you would never be able to turn it...The middle shaft goes to the turbine, which is the normal input under non-lockup conditions. The outer shaft is for the stator. Basically the fluid routing device that lets a torque converter multipy torque.
 
I wondered about that. The new converter has the direct drive eliminated, so that would make sense why one would turn easily and one would not.

Thomas
 
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