Strange Transmission Marking

[Ian S.]

Any ideas what this might be on my transmission? It feels kind of like plastic and has the 3-e mark.
Could something like this be removed without damaging the housing?

Thanks,

Ian

[Joe L.]

Re: Strange Transmission Marking

Ian-----

My guess is that the casting used for this case was defective and was repaired. Most likely this occurred at the foundry or the transmission assembly plant. I expect that the "3-e" marking is some sort of repair code.

Castings that were defective in some way were not always scrapped. In some cases, they were repaired. In fact, I have an NOS GM #3872765 exhaust manifold with the GM parts tag still on it that evidences some sort of repair in the upper portion of the manifold. In fact, the repair looks a lot like the one on your transmission case except that there is no code. With respect to repaired castings, I'm sure that it was not something done just for SERVICE parts----if they'd ship them into SERVICE, they'd ship them into PRODUCTION, too.

[Bill Stephenson]

Re: Strange Transmission Marking

Ian and Joe,

---------I suspect that the case was porous in that area. Dont know if the trans assembly line had some sort of check for porosity before the trans had oil in it, but the problem area may have been apparent to the naked eye. Once oil has gotten into the porous area it is difficult to get any kind of repair to stick to the aluminum..........Bill S