rebuilt 700r4 binding up in 3rd gear shift - Third Generation F-Body Message Boards

flyin89 · 03-29-2009, 09:35 PM

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 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 binden 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?

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

ed o · 04-01-2009, 02:58 AM

bindups are normally a sprag in backwards or a crossleak at a sealing ring (the sized ones). sorry for the bad info. doesn't sound promising with the trans in the car already.

if the trans binds-the valve body is probably doing its job because it commanded the gear to be applied but something isn't allowing the trans to do what the valve body asks. make sense? the valve body is the messenger. if it makes the shift happen (binds up).

the band is releasing because you are getting a 1-2 up and down shift.

the checkballs might actually be the issue. depending on year they go in different positions. the JR transgo shift kit explains it a little better than the 2-3kit, and the transgo separator plate 700-p instructions make life even easier. If I were you i'd borrow or buy both of them. it will help clear things up.

follow the 700-p instructions first, then use the other instructions (preferrably the JR). in that order!!!!
BTW/ nice ET and mile an hour. impressive....

flyin89 · 04-01-2009, 10:26 AM

Quote:

Originally Posted by ed o

1) bindups are normally a sprag in backwards or a crossleak at a sealing ring (the sized ones). sorry for the bad info. doesn't sound promising with the trans in the car already.

2) if the trans binds-the valve body is probably doing its job because it commanded the gear to be applied but something isn't allowing the trans to do what the valve body asks. make sense? the valve body is the messenger. if it makes the shift happen (binds up).

3) the band is releasing because you are getting a 1-2 up and down shift.

the checkballs might actually be the issue. depending on year they go in different positions. the JR transgo shift kit explains it a little better than the 2-3kit, and the transgo separator plate 700-p instructions make life even easier. If I were you i'd borrow or buy both of them. it will help clear things up.

follow the 700-p instructions first, then use the other instructions (preferrably the JR). in that order!!!!
BTW/ nice ET and mile an hour. impressive....

1) The sprags are new and I checked both so I'm sure they aren't the problem. I'm doubting its a crossleak however I would rather rulle out other possibilties before taking the trans out.

2) I agree 100%, the trans works perfectly except 3rd gear all gears are firm its definitely a valvebody or circuit problem.

3) However that won't mean that the band will be pushed away on the 3rd gear shift does it? I have been wondering about the capsule in that circuit on the way to the servo. Is there a way to airtest it? The capsule checked out okay with the trans bare and upside down. I have a brand new 700P plate. However I won't have the plugs that I had to put in the spacer plate.

The trans is a 1993 which has a few oddities that I have noticed.

Thanks for the help and hope you can further relate on this.

327_TPI_77_Maro · 10-11-2011, 02:27 PM

Did you ever get this fixed? Curious to hear what the issue was.