I have rebuilt a 700r4 (my 3rd) .500 boost, .296 reverse boost,vette servo,trans go 2&3 kit and a hardened sunshell. All specs are where they belong. The transmission (http://www.thirdgen.org/techboard/#) works fine in all gears but 3rd (D). 1-2 shift is nice and crisp 2-3 shift binds and feels like I suddenly had a 10k lb trailer hooked to it. It will stay binding as long as its in 3rd. 3-4 shift frees up and feels great. reverse is great.

It seems like either somehow the band is re-engaging or not releasing on the 2-3 shift. Any ideas of area I might want to check. Valvebody problem? Improperly drilled holes? :confused:

I'm hoping one of you guys can point me in the right direction.

I am no expert but if everything inside is correct then you could try the servo. I don't know which one you used but check and make sure it is together right and no cut o-rings.

The only thing that could be going on is the band is not releasing on the 2/3 shift. The band comes on during the 1/2, off on the 2/3, and back on again on the 3/4. What did you do with the check ball capsule in the case behind the servo? Some people like to remove it and block it off. I prefer to leave it in, and just make sure that the ball is free, and I always re-seat it, while the trans is still apart on its back, I check to make sure that it is not leaking by spraying penetrating oil and looking inside of the case. If any fluid leaks inside of the case, then it is not seating. This capsule is used for 2/3 release oil, and if it is leaking or the entire capsule is not positioned properly, it will cause the 2/3 bind up. If the band was too tight, you would probably feel a bind up in reverse. Just double check your work, make sure you have the correct valvebody gaskets, and you didn't get the upper & lowers swapped, check to make sure you didn't mis-locate your check balls. It is also very important to know the correct year of trans you are working on, as they had many design changes through the years. Do not continue to drive it until you have found the problem, it may be too late allready, and you may have allready smoked the band and the 3/4 frictions. PM me if I can help, Jim

The only thing that could be going on is the band is not releasing on the 2/3 shift. The band comes on during the 1/2, off on the 2/3, and back on again on the 3/4. What did you do with the check ball capsule in the case behind the servo? Some people like to remove it and block it off. I prefer to leave it in, and just make sure that the ball is free, and I always re-seat it, while the trans is still apart on its back, I check to make sure that it is not leaking by spraying penetrating oil and looking inside of the case. If any fluid leaks inside of the case, then it is not seating. This capsule is used for 2/3 release oil, and if it is leaking or the entire capsule is not positioned properly, it will cause the 2/3 bind up. If the band was too tight, you would probably feel a bind up in reverse. Just double check your work, make sure you have the correct valvebody gaskets, and you didn't get the upper & lowers swapped, check to make sure you didn't mis-locate your check balls. It is also very important to know the correct year of trans you are working on, as they had many design changes through the years. Do not continue to drive it until you have found the problem, it may be too late allready, and you may have allready smoked the band and the 3/4 frictions. PM me if I can help, Jim

I have checked the servo line-up, all that is good.

I checked the capsule when I was rebuilding it (A similar test to what you described only using actual ATF) and it was fine so I left it alone. The transmission is a 1993. Band was adjusted properly and I removed a washer beyond what the directions called for and still have the same result. I think its valvebody related.

Theres little chance of having smoked the band because I have not driven it beyond shifting into 3rd 3 times less than 10 seconds at the most moving onto 4th or shifting back to second as soon as I felt it was dragging.

Can I airtest the 3rd accumulator feed from the case to confirm it is pushing the pin back? Any ideas exactly which hole I need to air test (I have a ATSG for the 700r4.) If that circuit proves okay then its time to move to the valvebody,spacer plate or even the gaskets. I have the balls according to the transgo instructions for the specified valvebody. I know there are some differences in it being a 1993 trans but I figured they would know better than me. The biggest difference I noted was no scarf seals like the 4L60E.

EDIT: come to think of it the feed hole is a straight shot as for removal of the check ball capsule. How much pressure should do the job? shouldn't it seal tight?
I have yet to pull the pan and am trying to figure good areas to check and proper testing procedure before I crawl back under this thing. :(

Thanks for the help and keep the ideas coming as I have very few ATM.