question for hotrod on a TH350

[jake wells]

i got one in my 78 and it shifts a little hard into second but any other gear is fine. it smooths up after it warms up and i drive it a while than it is fine.

does my trans oil need changed i bought it a little while ago and the fluid is clean and doesn't smell burnt

OPPS i mean TH400 damn!

 

[HotRodPC]

Sounds like a broken accumulator spring to me. Its a common probelm on Th350's. But nothing to worry about . It can be changed on the outside of the transmission on the passenger side of the case. Its a bit tricky installing the seal after the change though. If you don't get it right, it will leak and leak bad cuz the accumulator is under high pressure, so it will blow all your fluid out quickly. Its fine if you can live with it. The accumulator springs purpose is to cushion the shift. In fact in most shift kits they ask that you remove the accumulator spring. Of course you keep the accumulator piston in, but just remove the spring. So if you want soften the shift, replace the spring. IF you can live with it, its not harmful.

 

[HotRodPC]

DOH, OK, now I see its a th400 were talling about. So differant issue now. It could also be the accumulator, but not a common issue on a Th400 and the accumulator is inside the pan. I'm thinking its more of a shift valve haning up. Also, how does it shift after warmed up as far shift points? Does it shift late or early? Could be a vac modulator, vac line leak etc. Whatever it is, not likley a major issue.

 

[jake wells]

shifts into 2nd at 20 mph and then to 3rd at 30 mph shifts smoothy but not late or early i thought it would shift into 3rd at 35 but i don't know im running 30 9.50-15lt tires on the back

 

[HotRodPC]

shifts into 2nd at 20 mph and then to 3rd at 30 mph shifts smoothy but not late or early i thought it would shift into 3rd at 35 but i don't know im running 30 9.50-15lt tires on the back

Your shift points sound OK, maybe just a hair early but not bad. To adjust that, you could get a tiny screwdriver put it inside the vac modulator where the vac hose connects, and turn the screw in clockwise to delay the shift a bit, and turn it out counter clockwise if you want the shift early. Seems you could use a full turn clockwise and your shift points would be perfect.

 

[jake wells]

ok can you post a photo on both th350 and th400 of were to adjust because i am lost.

i would like to get into 3rd a little slower in speed because i do mostly city driving and back roads i really don't get any faster than 30 mph maybe shift into 3rd at 25 mph because i rev really high putting around at 25 mph now