The Ford Barn

Adam/Mill Valley CA · 06-29-2021, 09:13 PM

Tranny for my '36 pickup, a 78- case(1939) with early gear set,behind stock babbitt-bearing motor, never abused, rebuilt about 9000 miles ago and worked perfectly, then in November broke two teeth off the reverse idler gear and two of the caged bearings failed. Rebuilt with good used caged bearings from MacVP, new cluster gear shaft and good used reverse idler gear-now after 1000 careful miles, a broken tooth on the low speed gear of the cluster shaft-all else looks fine including the caged bearings. The cluster gear was a new aftermarket item at the first rebuild(I believe from India, via MacVP). The low gear on the mainshaft really looks OK.

My question: The only issue I noticed during the rebuild was that the cluster shaft was basically a finger-pressure slip fit in the case, I assume from wear over the years. Is it possible this allowed some "monkey motion" between the cluster gears and the mainshaft gears, leading to the failure? Or any other ideas?
I'm getting entirely too good at R+R'ing this transmission!
Thanks,
Adam

06-29-2021, 09:13 PM	#1
Adam/Mill Valley CA Senior Member Join Date: May 2010 Location: Mill Valley,CA Posts: 275	More transmission woes Tranny for my '36 pickup, a 78- case(1939) with early gear set,behind stock babbitt-bearing motor, never abused, rebuilt about 9000 miles ago and worked perfectly, then in November broke two teeth off the reverse idler gear and two of the caged bearings failed. Rebuilt with good used caged bearings from MacVP, new cluster gear shaft and good used reverse idler gear-now after 1000 careful miles, a broken tooth on the low speed gear of the cluster shaft-all else looks fine including the caged bearings. The cluster gear was a new aftermarket item at the first rebuild(I believe from India, via MacVP). The low gear on the mainshaft really looks OK. My question: The only issue I noticed during the rebuild was that the cluster shaft was basically a finger-pressure slip fit in the case, I assume from wear over the years. Is it possible this allowed some "monkey motion" between the cluster gears and the mainshaft gears, leading to the failure? Or any other ideas? I'm getting entirely too good at R+R'ing this transmission! Thanks, Adam __________________ 1936 pickup, stock, black 1965 Mustang coupe 289/4bbl, black/red 1971 Alfa Romeo GTV 1750 coupe, dark red/tan 1970 911E 2.2 litre dark blue/black 1968 BMW R50/2 US, black (m'cycle) 1967 Triumph TR6R , sea foam/cream (m'cycle) 2022 Royal Enfield Interceptor 650 red (m'cycle) 1974 Honda CB750 red (m'cycle) 2000 Kawasaki W650 blue/silver (m'cycle)