727 locks up in rev

[Jim Morgan]

I have a pro-flight , 727 that has 904 internals, has been great just started locking up in reverse started
Like it was binding, took it a part found high gear clutches bad not terrible but was slipping didn’t see any
Thing else didn’t put it in made about 8 passes was ok went back to track week later first pass was good
But some times you don’t back up a lot, went out for second pass it didn’t want to back up,, was able to drive forward
Made a pass forward seamed ok so ran the race went 2 rounds then 3 on Sunday, never backing up, took. Trans out
Air checked clutches was poor took apart hi gear clutches getting black , didn’t see any seals or rings broke
What am I missing? Sealing rings any thing I should look at in valve body?

 

[dvw]

Are the high frictions and steels the only damage you can see? If it binds in reverse it's usually the forward clutch (rear location in the trans) siezing. Check the belleville spring for being cracked. When you air checked did you check thru the case? Or thru the pump on the bench? Checking with the pump on the bench you can test the high clutch by itself. I'm assuming you didn't pressure test before removing it? Did the trans brake hold? Or did it creap? Did it slip in 3rd? I just had a similar issue with a Pro trans. Number One culprit is misadjusted shift linkage. Or going 1 to 3 on the shift. Look at the stator support very carefully for cracks.
Doug

 

[GTX JOHN]

Would an issue with the planetary gears possible cause
that problem?


Could be worse: I just broke my rollerized output shaft in two on the Protrans
in the stocker last pass.

 

[Jim Morgan]

Are the high frictions and steels the only damage you can see? If it binds in reverse it's usually the forward clutch (rear location in the trans) siezing. Check the belleville spring for being cracked. When you air checked did you check thru the case? Or thru the pump on the bench? Checking with the pump on the bench you can test the high clutch by itself. I'm assuming you didn't pressure test before removing it? Did the trans brake hold? Or did it creap? Did it slip in 3rd? I just had a similar issue with a Pro trans. Number One culprit is misadjusted shift linkage. Or going 1 to 3 on the shift. Look at the stator support very carefully for cracks.
Doug

Did ck cable adj (its push button) did drop valve body to air ck didn’t hear any thud but I was thinking with only 60thou clearance wouldn’t hear much, but when air cking the clutches did get air out of the other clutch, got it apart other than hi gear discs getting black, is there any ck balls in valve body,in
A flow diagram shows a#4 but no discription