Posted 2019-07-14 12:10 PM (#584810) Subject: Upshift low to high when first starting
My 1956 Custom Royal (Super Red Ram V8 4bbl Polyflite), when first being driven for the day, does not shiift from "low" to "high"---it hangs in between as though in neutral. Slowing down, pushing the neutral button, then back to Drive, and moving again will take 3 or 4 attempts before it shifts correctly. Once all of that is out of the way, it works fine the rest of the trip!
Any suggestions will be greatly appreciated!
Posted 2019-07-14 2:23 PM (#584816 - in reply to #584810) Subject: RE: Upshift low to high when first starting
Most likely the seals in the direct clutch are hardened/shrunk and won't hold pressure when the transmission is cold; when the fluid warms up a little, the seals expand and will hold pressure allowing the transmission upshifts.
Other than an overhaul with fresh seals, you might try an additive like Trans-X or Lucas to soften the seals.