20-09-2020, 09:15 AM
I've done my first ever gearbox re-build and it seemed to go well except that first gear and reverse are not at all smooth - you can feel each tooth moving or rubbing against something.
This is one of the boxes that has shims on the 1st/2nd selector shaft, and when I dismantled it there were no shims at all.
Apart from a general clean out and new bearings, the only changed part was the reverse gear wheel from another gearbox as my old one was going through the hardening.
I put a shim in the laygear to bring the float on the layshaft to be 5 thou.
I adjusted the 3rd/4th fork to put the selector mid way between the synchro cones and then made up a shim to bring the 1st/2nd forks in line. From memory, the shim was about 20thou. I then adjusted the reverse fork to match.
Initially first gear was at times locking against something, but after I added the oil it does not snag so much, but clearly (and audibly) all is not right. My motor and the rest of the car are far from ready for a run on the road, so what I am reporting is what I notice when turning the first motion shaft when the gearbox is set in first or reverse. All the other gears select ok and the box feels really smooth.
Any suggestions please! I'm an electronics engineer, so mechanical stuff is delightfully new to me.
This is one of the boxes that has shims on the 1st/2nd selector shaft, and when I dismantled it there were no shims at all.
Apart from a general clean out and new bearings, the only changed part was the reverse gear wheel from another gearbox as my old one was going through the hardening.
I put a shim in the laygear to bring the float on the layshaft to be 5 thou.
I adjusted the 3rd/4th fork to put the selector mid way between the synchro cones and then made up a shim to bring the 1st/2nd forks in line. From memory, the shim was about 20thou. I then adjusted the reverse fork to match.
Initially first gear was at times locking against something, but after I added the oil it does not snag so much, but clearly (and audibly) all is not right. My motor and the rest of the car are far from ready for a run on the road, so what I am reporting is what I notice when turning the first motion shaft when the gearbox is set in first or reverse. All the other gears select ok and the box feels really smooth.
Any suggestions please! I'm an electronics engineer, so mechanical stuff is delightfully new to me.
Slowly rebuilding a '34 RP