Hi, people. I just installed my factory tech valve body for the 4r70w transmission. I do like the way it shifts but it has a problem that it did not have before. When driving along at 35 to 40 at light throttle, when it makes it's shift from 3rd to 4th gear, it has a slight flare-up. The rpms will go up about 300 rpm, then will make it's shift. If you are into the gas harder, it shifts just fine. I gotta say, i do like 1st to 2nd and 2nd to third alot better!!
Also, if you hold it in 3rd with the overdrive button and at light throttle, then push the botton to let it go into overdrive, it will flare up. Anyone have the same problem?

 

Actually i think mine does something like that. When i get on it hard from a stop when it shifts from 2nd to 3rd it seems to jump rpm right before it shifts. I dont know if its normal or not but havnt had any problems yet. Only does it wide open throttle.

 

Do you have the factory tech valve body?

 

Couldnt tell you. I never put anything like it on unless the guy before me did. If it comes factory on some then maybe. Guess im not sure on that one.

 

Thats usually a sign a burnt OD band. Knowing exactly how a factory tech valvebody is built and most of what changes I can't see why you would have an overdrive problem. Overdrive is controlled by the servo underneath the valvebody( the small one). The factory tech valvebody mostly adjusts the 1-2 shift, 2-3 shift and lockup apply pressure.
Alan

 

I fixed the problem. I called Factory Tech Transmissions and talked to a guy named Bob Rilley. He told me to send back my factory tech valve body and he would send me a "b" plate kit to use on my old valve body. I did the swap today and all is well. No more flare-up from 3rd to 4th. There must have been something wrong with there valve body. I am suprised I even had a problem with all the positive feed back I have read on the forums about these valve bodys. But the company worked with me and the issue is resolved. It shifts much better than stock. While I was back into it I reinstalled the lower stock spring in the 1-2 accumulator to soften up the shift. I gotta say, could be a little too soft for me but it shifts much faster! Maybe later I will take it out again and try it. Just thought you guys might like to know how it went.