[gonzo08383]

here's the issue: trans is newly rebuilt. all standard parts replaced ie:clutches, seals, o-rings, gaskets, etc. trans has b&m shift kit installed. its actually a th-350-c, ya know, lockup converter(not hooked up tho) lockup not used pulled from a wrecked 87 scottsdale, 9"tailshaft. trans fluid normal. no leaks. manual valve is adjusted properly, governor working properly, case vent installed(shouldnt matter). now that thats out the way......trans when cold will take its sweet time engaging from park to drive, park to reverse, basically you put it in gear and it will start moving when its dang good and ready. once hot and been driving for a bit it will go from park to drive or reverse with no problem. now i have noticed that it seems to need more "gas" to move in reverse almost like theres lots of stall in the converter(which is 1800rpm btw). it shifts firm and fine, just finicky when cold. not sure if i have a valvebody gasket leak or the low/reverse piston is leaking down. maybe the direct drum piston is leaking down seeing as its not discriminating from foreward or reverse? just curious as to what is causing this. trans is out the car and i'd like to know what to look for BEFORE i tear it down. i did install the piston seals with a dulled out hacksaw blade which is why i suspect apply piston leakdown. other than leaking seals on apply pistons does anyone else have any good ideas? kinda stumped. thanks

[joshp83]

did u use teflon sealing rings thell do that in a th 350 and 400 use metal rings make sure the drum is wore were the rings go also look at the boost valve in the valve body if wore will do that to sonnax sells a replace ment there about 70.oo if u have a non lock up valve body se if the boost valve is bigger most are and if not wore out use it the boost valve is in frront of the pressure regulator spring

[gonzo08383]

i used whatever seals came with the rebuild kit. i know the band is kevlar and i have the alto red eagle clutches. i didn't fully install that shift kit. not out of laziness tho, needed the car to run asap. i left out the spring in the valve body because i couldnt figure out how to get that darn roll pin out to release the valve. someone told me the trick to it but i forgot how it goes. the pins are in blind holes so i cant just tap them out. the trans isnt being used right now. i dont have a car to put it in, just want to fix it while everything is easily accessible. will bolt it to a warmed over 350 to test it out once i'm done.

[0trbo4myCHEVUICK]

Sounds like a fluid flow issue somehwere.

[joshp83]

if u got a parts store overhaul kit they usually have teflon rings start from scratch look at the drums closely and the valve body

[gonzo08383]

ima check the valve body and install that spring i left out. my next silly question is where do i get replacement valvebody gaskets? havent heard back from b&m. the transpak gaskets are different from stock so i'm not sure where else to get them. unless i can reuse the gaskets(which i'm sure i cant). i may sell that engine i mentioned above, whats a good price for a 350 bored 60 over, performance heads with 202 valves making 310ft/lbs to the wheels and 240hp @wheels, flywheel numbers dont matter. these figures were calculated by chassis dyno 98%humidity 97*outside, third gear pull(1:1 ratio) so the numbers are accurate as can be. engine will be sold turnkey with accessories, drop it in and go. has 1000 miles on it. .030 dished pistons perfect for boost, no nitrous pistons are hypereutectic. its an eagle rotating assy. block is an 87, mech fuel pump, 2 bolt main, 2 piece rear seal. just not sure what a fair price on it would be. smokes the tires easy with an 1800 stall. good lil truck motor i think, not right for my camaro. an ls7 however....

[joshp83]

just make the two holes under the transfere plate

[tnsmith10]

Originally Posted by gonzo08383

here's the issue: trans is newly rebuilt. all standard parts replaced ie:clutches, seals, o-rings, gaskets, etc. trans has b&m shift kit installed. its actually a th-350-c, ya know, lockup converter(not hooked up tho) lockup not used pulled from a wrecked 87 scottsdale, 9"tailshaft. trans fluid normal. no leaks. manual valve is adjusted properly, governor working properly, case vent installed(shouldnt matter). now that thats out the way......trans when cold will take its sweet time engaging from park to drive, park to reverse, basically you put it in gear and it will start moving when its dang good and ready. once hot and been driving for a bit it will go from park to drive or reverse with no problem. now i have noticed that it seems to need more "gas" to move in reverse almost like theres lots of stall in the converter(which is 1800rpm btw). it shifts firm and fine, just finicky when cold. not sure if i have a valvebody gasket leak or the low/reverse piston is leaking down. maybe the direct drum piston is leaking down seeing as its not discriminating from foreward or reverse? just curious as to what is causing this. trans is out the car and i'd like to know what to look for BEFORE i tear it down. i did install the piston seals with a dulled out hacksaw blade which is why i suspect apply piston leakdown. other than leaking seals on apply pistons does anyone else have any good ideas? kinda stumped. thanks

is the filter tight? did you use the provided gasket? if so, id be looking at the pump as there are different gear thicknesses for the 350 pump.
a pressure check cold can confirm this.

[gonzo08383]

filter is tight, pump working fine. no slip once it feels like working. just that initial throw into drive. after that i can park it(without shutting the engine off) and throw it back into gear and no problems. just a finicky lil trans

[anglia427]

forward and direct outer piston lip seals are slightly different in size you got them correct?

[gonzo08383]

Originally Posted by anglia427

forward and direct outer piston lip seals are slightly different in size you got them correct?

yeah they are correct.

[joshp83]

i still think its the regulator valve in the valve body

[gonzo08383]

Originally Posted by joshp83

i still think its the regulator valve in the valve body

yeah you may be right. i'll post when i have time to tear it down. def looking hard at that valve body

[joshp83]

just went threw that 2mo ago on a street rod also look for groves cut into the fwd drum from the rings

[tnsmith10]

Originally Posted by gonzo08383

filter is tight, pump working fine. no slip once it feels like working. just that initial throw into drive. after that i can park it(without shutting the engine off) and throw it back into gear and no problems. just a finicky lil trans

this is common with 350's, this only happens when cold after sitting all night basically. it wont want to move. once the pump primes, everything is fine. the reason i know this is the problem is because i had one in a car i used to own. i put it together with leftovers that my dad had. the trans was complete but, a basket case (he used to have built units on the shelf so he just swapped in another unit). everything was cherry but the problem was exactly what your dealing with. by the time i got to it, my dad had forgot what the problem with it was and i threw it together.
so, if you still dont think thats the problem, hook up a pressure gauge and see what you have for pressure when it doesnt want to move.