63 F-85 Hydramatic issue

[Guest Oldsaddict]

Hi Guys, great site, can’t believe I haven’t found it before!
I am the proud owner of a 63 F-85 convertable with the hydramatic. I love this car, it gets lots of looks wherever I go, drives great, but I am having a problem with first gear in my hydramatic. The symptom is that it slips if you give it too much gas from a standing start, just like you are pushing the clutch in and slipping it, as if it was a manual. If you feather it from a start you can get going, and as soon as it shifts into second it’s fine, no slipping. No slipping in third either.
I know these transmissions are a different animal, expensive, and harder to work on. I can’t afford to rebuild this transmission right now, but I do not want to park it for the season either:( Anybody know if the first gear of this transmission can be repaired or perhaps adjusted? I have had it mentioned about adjusting the band, but I believe that has been done. Can the band stretch to the point where it has no adjustment left? Can I replace the band?
Any Hydramatic guru’s out there??? Anybody know one???
Thanks guys!

[joe_padavano]

Welcome.  As you may know, your car has a RotoHydramatic 5 transmission, which is unique to the 1961-63 F-85 cars.  There was no other application of this trans.  Also, don't be fooled by the "4S" designation.  This is not a four speed trans, despite what Olds may have called it in the Chassis Service Manual.  It is really a three speed trans with a fluid coupling inside the trans.  This stator in this coupling is locked and unlocked for "first" and "second", which changes the torque multiplication from what is actually the same planetary gear set. The trans is also very sensitive to adjustment of the Throttle Valve rod that runs from the trans to the carb.  Unfortunately, the special gauge tools called out in the Chassis Service Manual are not readily available, making correct adjustment a trial-and-error process. If you've converted to an aftermarket carb, this can be even more problematic.

 

I did convert my 62 F-85 to an aftermarket Edelbrock carb and had to fabricate my own throttle linkage.  It took about a month of trial and error adjustment of the TV rod until the trans shifted acceptably.  If the rod is too long, the trans will likely slip excessively.  If too short, the trans will upshift too soon.  Unfortunately, if the TV rod has been mis-adjusted for a length of time, the bands or clutch disks in the trans may be excessively worn.

 

If you don't have a factory Chassis Service Manual, I strongly suggest that you get one.