transmission

Need help/advise from anyone. I am really disappointed in my truck lately. It has 76K miles on it. Like everyone always says, I baby this truck......driving it and maintenance wise. My problem is this, after driving the vehicle for awhile 45 min- 1 hr, the truck shifts hard into 1st gear. When I'm at a stop and begin to accelerate, the tranny appears to bang/knock into gear. Sounds/feels awful and definitely not good for whatever the problem is. Any advise?

Sounds like it could maybe be sticking in second, and downshifting as soon as you touch the gas. To find out if that is the problem, put it in manual first and see if it still does it.

Also, if it is a model that uses vacuum lines to sense vehicle load, check to see that all the lines are connected and there are no leaks. Use a vacuum guage to see if the vacuum is strong too.

sounds to me like high line pressure. Have someone check the force motor (EPC) in the tranny. $70 parts if its bad.

Thanks guys for the advise. I will have to look into this further.

One other thing. I failed to mention that this is an automatic trans. Unknown if this has any bearing on your responses. Thanks again.

Is the hard shift an UPshift or A DOWNshift?? What year truck??

The truck is a 2000 silverado. I was incorrect in my earlier entry. The truck shifts hard into 2nd gear. It does it on an upshift.

gilman,
You said in your other post that the check engine light came on. I bet it is P1870 which is very common on the 4L60E. The Transgo Reprogramming kit I talked about may not fix the problem (I need to read the instructions that came with my kit); however, this is the part that you need to fix your problem http://www.transmissionspecialty.com/parts/parts/77754-Combo.htm

I have heard this part installed is around $250.

If you do a google search on P1870 you will find lots of information.

//2000CAYukon

gilman,
You said in your other post that the check engine light came on. I bet it is P1870 which is very common on the 4L60E. The Transgo Reprogramming kit I talked about may not fix the problem (I need to read the instructions that came with my kit); however, this is the part that you need to fix your problem http://www.transmissionspecialty.com/parts/parts/77754-Combo.htm

I have heard this part installed is around $250.

If you do a google search on P1870 you will find lots of information.

//2000CAYukon

You shouldn't have to fix it. GM should build a better product.
All we do is work on this GM junk.

YUKON, you hit the nail on the head. I found this other site on the net and there were about 35 entries from people experiencing the exact same prob. One other guy who owns a tranny shop made the exact same suggestion as you and swears by it....the sonnax tcc reg valve kit. This is definitely the route i'm going. Next problem is where/who should i take it to? This guy owned a tranny shop but he is located in pennsylvania, i'm in california....ha! This sounds like a common problem countrywide, do you think a local tranny shop or AAMCO, could install this product. Thanks again.

Where in California are you? I am near San Jose.

Personally, I had a bad experience with Ammco. They quoted me one price, then when I picked it up, it was $300 over the quote. They claimed they tried to call me. I will never go there again. This was for my wife car (right after we got married).

If you are a AAA member, you can look up AAA backed shops on www.csaa.com

//2000CAYukon