I have a 52 Chevy stick 3 speed stock trans. It has begun to jump out of third gear at various speeds,. I understand this was a common problem with them. I am looking for a trans rebuilder in Michigan and some insight as to is it the Synchro or the main drive gear causing the problem. Any thoughts are appreciated.
I would say that if it's popping out of gear and your going to break open the case, replace the gear and the synchro. If you do one and not the other, there is the possibility that it won't go in gear at all when your done.
Had a 52 Chevy pickup that did the same thing; easy fix...at least easy to try this first. Pull off the side cover on the trans ; the one that your two shift arms hook to the two shafts comin out of the trans; pull it strate off,(you mite not even have to unhook the shift arms) you will see a "u" shaped shift fork on each shaft; turn the 2nd/3rd gear "u" 180 degrees and re***emble. What happens is that "u" gets worn on one side and stays like new on the other. This may fix your problem/may not...but on my truck which acted just like yours, it fixed it and worked like new! Try it, you may get lucky. Good luck.
Your problem is more than likely worn syncro teeth on the speed gear and the syncro drum. If this is the case the only fix is to replace the worn parts. Both the speed gear and the syncro drum, throw some new br*** syncro rings in while you are there and the problem will be resolved. The other suggestion about the shift fork being worn may be a contributing factor, inspect them for wear and replace as needed. Trying to just patch it up doesn't solve the problem. Good luck.
The more that it does it the more that it will taper the gear. All good advice here...short term fix...and to address it with appropriate parts. Check with a local builder...these trans are not that much to get completely rebuilt....good luck.
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