Quick background: 1985 Camaro, newly built 383. I used the stock 700R4 trans, but purchased a full rebuild kit through Dana (from these boards, Pro Built Automatics) as well as a 2800 stall converter. I had a local trans shop that my brother (35+ years in business as a mechanic) and I have a long, good history with do the actual rebuild, but we installed the trans ourselves.

When I finally got the engine running right, I went to back the car out of the shop and thought that something wasn't right, like I had to give it a lot of gas to get it to go backwards. Took it for a very short ride, like 3-4 blocks and pulled it back in. A few days later, went to back it out again and no problems at all. Did this 2-3 times over the last couple of weeks. On Sunday, backed the car out, went and filled up the tank and then pulled it back in, where it sat until yesterday.

Yesterday, I got in the car and went to back it out - no reverse. The car would go into neutral and drive. Checked the fluid, it's full and isn't burnt. We pushed the car out and I took it for a gentle 10-12 block ride, it seems like it's not shifting correctly like the way it was when I drove it the other couple of times. Since I haven't driven it much, it's hard to determine if it's shifting differently or if it's maybe starting off in 2nd gear or something like that but I really don't know.

I called the trans shop and they said they can take a look at it but not until next Wednesday. I'm not in a huge hurry, but (1) wondering if there is anything easy I can look at before then and (2) when the "most likely" cause of this is - bad parts, incorrect install, something just broke, etc. Thanks.

 

I had the same problem after i rebuilt my trans and forgot to clean out the torque converter and trans cooler, my tv valve and my boost valve was clogged with dirt from the uncleaned parts. Take your valve body out and clean it. Flush out your converter. My trans also shift extra hard into 2nd.