[jws]

I,m rebuilding the transmission in my '85 Silverado and have a question. After putting the input clutch assembly together I air checked for leaks. The 3-4 piston activates and holds with no leaks. The forward piston ( the middle hole on the shaft) also holds with no leakage. But when I apply air to the top hole the piston activates but I get leakage back out of the middle hole on the shaft. Is this normal? I have pulled it apart 3 times and checked every seal they are perfect. This is the first 700R4 I've built and don't have a fluid flow diagram. I built a lot of 350 and 400 transmissions back in the 70's but this creature is a hole new ballgame. Any help would be greatly appreciated.
Thanks,
John

[scholman]

jws,

There is a white plastic sealing ring that goes in there. It plugs that port when you install the clutches. This part also keeps the input shaft aligned with the output shaft.

Good Luck
Scholman

[jws]

Thanks for the quick reply. So your saying this port seals with the teflon rings thru the stator and back to the valve body for the over run clutches? Just want to make sure I've got it right.
John

[Crosley]

Originally Posted by jws

I,m rebuilding the transmission in my '85 Silverado and have a question. After putting the input clutch assembly together I air checked for leaks. The 3-4 piston activates and holds with no leaks. The forward piston ( the middle hole on the shaft) also holds with no leakage. But when I apply air to the top hole the piston activates but I get leakage back out of the middle hole on the shaft. Is this normal? I have pulled it apart 3 times and checked every seal they are perfect. This is the first 700R4 I've built and don't have a fluid flow diagram. I built a lot of 350 and 400 transmissions back in the 70's but this creature is a hole new ballgame. Any help would be greatly appreciated.
Thanks,
John

normal stuff

[jws]

Thanks, Crosley. I'm hoping to get it right the first time. Everything is a lot heavier than I remember 28 years ago and crawling around under the truck hurts a lot more than I remember too.
John

[Crosley]

Originally Posted by jws

Thanks, Crosley. I'm hoping to get it right the first time. Everything is a lot heavier than I remember 28 years ago and crawling around under the truck hurts a lot more than I remember too.
John

I understand.......

[Jmark]

My ATSG manual said to physically cover the center hole with a spare finger when applying air to the top hole. Guess that 'splains why it was blowing air? LOL

Mark

[jakeshoe]

Originally Posted by jws

Thanks, Crosley. I'm hoping to get it right the first time. Everything is a lot heavier than I remember 28 years ago and crawling around under the truck hurts a lot more than I remember too.
John

That's why I quit crawling around on the ground doing transmissions.



I like this view better

[Crosley]

Originally Posted by Jmark

My ATSG manual said to physically cover the center hole with a spare finger when applying air to the top hole. Guess that 'splains why it was blowing air? LOL

Mark

it is the design of the drum and seals..... manual? there are books for these ?

[Jmark]

Originally Posted by Crosley

it is the design of the drum and seals..... manual? there are books for these ?

Yea, there are books. I thought you wrote them? That's why I like hanging out in this forum, always learning stuff!

[jws]

Thanks for all the help gents, I was 'bout to pull what few hairs I left out. I have the Haynes manual but it doesn't say anything about blocking the center port while checking the top one. I got use to following fluid flow diagrams to diagnose problems the last 15 years I worked on heavy equipment. So I was a lost ball in high weeds on this with the Haynes book.
Jake, that's right, rub it in. You've got a great set up there. I'm planning on a hoist in the new garage I'm building for the frame off on my '70 Chevelle if I live that long. The truck had a mind of it's own and gave up to early.
Again thanks for the help.
John