decampos

I have sourced a replacement identical transmission from a 116,000 mile junked car (that had been off the road for 3 years or so) to replace the incumbent failing unit. I was told the transmission 'ran great' prior to the car being parted out. There's no guarantee. The plan is to swap my faulty 'box with this possibly good 'box and hope for the best. If it's also buggered, then I bite the bullet and stump up the cost for a rebuild or a reconditioned unit.

So today I opened up the 'new' unit from the donor car. Was somewhat non-plussed to find rather a lot of deposits in the oil pan. Fluid looked a little dark though it didn't smell burnt. Filter looked like it'd been a good while since the last service. The deposits didn't feel like metal, were kind of crumbly.

Anyone care to comment on any of this? (coin is for scale, it wasn't found in the pan).

Very much appreciated.







Sludgy

The Deputy

I'm trying to make out those two larger pieces in the pan, they look to have rounded edges. Maybe some sort of thrust washer or locking washer. I have never had one of these automatics apart, and never hope to...lol, but have had several other American made auto transmissions apart...and those pieces of metal are much bigger and numerous than I would like to find...and personally, l would never use a trans with pieces like that inside. I'd have it looked at by a professional.

Good luck.

Brian.

G8RB8

You're in Greg Brown's territory. Take it to him.

James Bailey

all depends on whether you have more time or more money ....and if you need the 928 fixed right away.
If you believe that the trans was working it should still work for you....so button it up and stuff it in. If it does not work then go to plan B but you might not have the 928 fixed for a while. Those early transmissions are pretty strong but now are also pretty old.
Putting it in is "just" your labor and a filter kit plus fluid....everything else needs $$$$$

GregBBRD

The chunks of fiber material in the picture of the oil pan with the fluid in it are clutch disc pieces from either the B1 or B2 clutch drums. The fine material sitting on top of the filter is also clutch disc material.

In the close-up picture of the pieces in the oil pan, I can't tell much about the metal chunks from a picture. The chunk that appears to be round and dark is probably an internal O-ring that has either split or broken. Since there are no "extra" O-rings inside these transmissions that do absolutely nothing, you can almost be guaranteed that there will be an internal oil leak, allowing needed oil pressure to escape.

Unless one's time is completely worthless or one just wanted the shear joy of swapping out one of these transmissions, it is very doubtful that this transmission is worth the time to install.

decampos

Thanks for the replies guys.

Great info. Thanks.

G8RB8

So Greg, lets say you were presented with these two trannys and asked to return one good one, would you do some sort of deal for the other? Just curious.

GregBBRD

The short answer is that if you happen to have two of these things, it sometimes makes sense to use two to help make one....

"Core value" depends on the year. The transmissions up to 1989 need so many updates that the cores have little value....unless you happen to need one of the "hard parts" inside. Virtually any internal "hard part" that needs to be replaced costs more from Mercedes than almost any "core"...so at that point, taking two apart to make one is a good idea.

The internal seals and O-rings turned into a rock hard material many years and heat cycles ago....so the clutches have generally been slipping, which ruins the steel plates in the clutches. (Yes, I know that the majority of the "rebuilders" sand down the hot spots to re-use the steel plates....which is one of the dumbest things anyone has ever done....this simply reduces the available surface area.) Therefore, one is unlikely to "find" steel clutch pieces that can be used....but since these have gotten "stupid expensive" in the past couple of years from Mercedes, it is worth the time to look.