VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1936 Standard transmission clunk in 1st and 3rd gear

I had my '36 standard transmission rebuilt several years ago, but just recently installed it.
Without the drive shaft disconnected, it appears to work fine, however with the drive shaft connected I get a rotational "clunk" sound in first gear, and a "searing" sound in third. Second and reverse sound OK.
I thought it was the speedometer gear bouncing off the drive gear, however when I removed the speedometer gear from the case, it still makes the noise. I replaced the u joint, which made no difference. When I slide back the u joint ball housing to see the exposed u joint while the the car is running (on jack stands) it appears to "hop" about 1-2mm, and still makes the noises. The drive shaft spline shows no lateral movement, so I think the bushings are OK. Any ideas?
Thanks, Steve

I doubt if any wear or problems in the transmission will be noticeable with the drive shaft disconnected. The only load on the transmission gears is the inertia created by their own mass. That is not much.

My guesses are that the rear bearing in the transmission is worn or the bolt that pulls the front half of the u-joint on to the transmission output shaft did not seat things correctly.

I assume you installed a new u-joint. Did you compare the old and new parts closely? Are the cups fitting snugly on the shoulder of the trunnion? My unfortunate experience these days is that about half the time there are issues with replacement parts.

Thanks Rusty. I'll check the seating of the front yoke of the U joint. May not be seated properly.