I finally got the courage up to tackle the transmission problem. The problem was: “did I do any damage to the transmission?”. I had let the transmission run very low on fluid and it got hot enough to discolor the fluid from it’s normal red to a sort of brown color. I could have just changed the oil without removing the pan – I am told it can be done (no drain plugs in OEM transmissions) – but I figured that if I did anything bad I wanted to know and the only way to find out would be to drop the pan and look for bad stuff – pieces of metal or something else.

Pieces of a thrust washer?

I pumped most of the oil out of the pan using a Harbor Freight “transfer pump” that I paid $8 for and then removed the pan to find lots of pieces of metal (see the photo at left).

I called JimK and sent him this photo. He didn’t know what it was but suggested checking with Manny (the GMC transmission guru). Manny is not positive, but is pretty sure, the pieces are from a “thrust washer” and the transmission should be replaced. The strange part is that Manny does not think that the heat alone could have caused the thrust washer to fail, if at all. He suspects a vibration somewhere like from a loose pinon gear or a misaligned transmission. I am hoping he can figure it out once he gets the tranny back after I replace it.

Still trying to figure out how to get this done. The one good guy that anyone knows of in Tucson has retired and the guys who took over for him apparently have no interest in doing this.