I recently put a salvaged trany (70k miles) in my 01 blazer. I have been driving it for 2 1/2 months with no problems, and then last night it wouldn't shift out of second gear. I thought maybe it was the cold, so today I let it run for 30 minutes before driving, and it was the same problem. When I manually shift into 3rd the car just revs like it's in neuteral. While I was transporting my new transmission the main wire connection on the drivers side was damaged. The pins were ok, but the plastic casing was broken. Could this problem be electrical? Does anyone know what might cause this kind of problem?

Thanks,

John

 

Yes it most likely is electrical. If the protective casing is broken around the pins moisture will throw off the electrical signal. Your engine light is probably on and youre in limp home mode. Is this problem intermittent or is it constant now? If your engine light is on what is the code? I had a similar problem with my truck and it took me a loong time to figure it out after I checked every single wire from the battery to the tranny itself. Its hard to determine where the problem actually is but i would start at that connector first. Inspect for corrosion.

 

I broke down and took it to the dealer. They told me it was something internal, and they would have to remove the tranny, and take it apart to troubleshoot ($1900+ whatever they find wrong). So I bought a new one, and installed it myself this weekend. Thanks for the response though.

 

Well three weeks and $2000 later I found out that it was the mass airflow sensor, and the dealership misdiagnosed my problem. I never needed a new tranny. After I put the new transmission in, it still had the same problems so I took it back to the dealership and they told me again that it was a bad transmission. I figured that was bogus, so I took it to the place I bought the transmission,and in ten minutes they told me what it was and ordered the part.

 

I am sorry that things worked out as they did for you. As you have found out, dealerships are not always the best at transmission diagnosis. It typically pays to have a true transmission shop look at it for a 2nd opinion to see if the diagnosis matches. The unfortunate thing here is that GM even has a TSB about MAF sensor contamination causing weird transmission problems.