I just got done rebuilding my transmission, and got it into my truck, installed a transgo reprogrammer on the vb. I test drove it and the foward gears are great 1-4 shift good and act fine, the problem is reverse slips under very light throttle (bad, it will barely move the truck) and when the converter locks up it slips too. Im pretty sure these two problems are connected, maybe a seal is rolled on the od piston? Before i tear it back down i wanted some suggestions.

Dave

 

BTW the bands are adjusted correctly, and double checked

 

Run pressure checks that will tell you if seals are leaking in Od, front rear servo, check ball problem what not. Heres the instructions and diagrams,

 

I guess you'll have to save then print, which wouldn't hurt to have anyways.

 

Thanks DodgeFreak.
I plan to rebuild a 1990 CTD 727 this winter. the tranny slips in low and second when pushed hard. Minus the OD, the pressures should be similar I would think.
I rebuilt a gasser 727 years ago and one trick that I learned was that when installing the clutch drum with an outer seal on it. Put a piston ring compressor over the drum with the seal on it. Then put the setup in a freezer for an hour or two. Take it out of the freezer, REMOVE The Ring Compressor and immediately instal the clutch drum into the tranny while the seal is still cold/compressed. That saves ruining the new seal when instaling it.
Ray

 

From the first post. OD seal will not affect reverse or lockup.
Check pressures as the svc manual instructs.
How far apart did you take the VB? Sounds like got a check ball out of position or valve fubarred. Possible input shaft seals but doesn't seem likely.
JMHO

 

I had the valvebody all the way apart! the checkball are in the right spot i think, ill do pressure tests as soon as i can get a chance, i wish i could narrow down the vb or the transmission, maybe i should have done one at a time?

 

The fluid is a little burnt too just from a 4 mile test drive

 

If its burnt drop the pan....if theres alot of clutch material you might go a head and do the pressure test then drop the trans and pull it apart again to see how the clutch packs are.

 

no clutch material in the pan, the fluid is just somewhat darker and has a slight burnt smell to it. Where can i get a gauge from, the cheapest one i could find is 72 dollars...

 

Can you rent one or something from Orielys? also i think you'll need 2 of them because you have to compare readings.

 

O riellys said they dont have them to rent and told me to check a transmission shop to see about getting one. The transmission shop said bring it on in and they'll diagnose it for a good fee....

cheapest i found was 72 bucks a piece, still weighing my options