I recently acquired a 39 convertible that has the most smooth shifting and quiet 39 trans I have ever owned... BUT, it likes to pop out of gear going down hill. Seems like 3rd won't pop, but 1st and 2nd is definitely a h***le. If I push in the clutch and push on the shifter slightly I can feel it go back in (before it pops all the way out of gear). Doesn't seem like a synchro problem as this trans is so smooth.. Shifter forks? Anything else I might be able to sort out without major surgery? Thanks
I would think that you could tell by the feel of the shift lever with car shut off? Lightly move it just barely back and forth, to feel for slack in the forks? 39 convertible is the cats azz...that shorter roof and longer deck, compared to the 40... .
From: The New Thompson Repair & Tune-up Manual 1935-1940........... May have something to do with clutch pedal adjustment.....see pedal lash paragraph below...
Beautiful car!!! I really have nothing productive to add, but when i read the ***le, i first thought there was gonna be 39 questions about 3 speeds. Again, absolutely beautiful car though. T
Usually it's said if it pops out of gear on second that the clearances of the main ***embly to the case is too much. The bushings are available in different thicknesses to compensate (up to a point). Google Mac VanPelt and see his wonderful website for parts and a great book on the early Ford transmission. He's a HAMB member too.
I agree it's a beautiful 39! I suggest you get a hold of Van Pelt Sales. Mac Van Pelt has written a very good book about the early Ford transmission. He also sells parts and rebuilds transmissions. He writes in his book that your shifting problem "is generally result of a combination of faults. Badly worn gears,worn thrust washers, a worn case, worn shifter fork, worn shifter shaft detents, and broken or weak shifter detent springs are all items to inspect. Any one defect can be a cause, or contribute to symptom along with other defects listed." There is more to this found on page 26 of his book called The Ins and Outs of Early ford Transmissions. It can be found here http://www.vanpeltsales.com/FH_web/flathead_trans-repair.htm I had this popping out of gear problem and rebuilt my transmission using Mac's book and some personal advice from him over the phone. It has only popped out of gear one time since rebuilt 2 years ago. Hope you get it fixed soon so you can enjoy driving that beauty! Edit: Guess it took me too long to write this as others have already made these recommendations.
my understanding was the cluster gear is the culprit for popping out of second. keep the thrust clearances on the cluster as tight as possible.
Completely eliminated the problem by replacing the detent ball springs with the stiffest springs I could find, from the hdwe store. Did not make shifting noticeably stiffer due to the leverage ratio with the long shift lever. This will not always cure the problem, but I would try it first. Greg
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