My recently rebuilt transmission has roughly 1400 miles on it. Yesterday, it started popping out of second during downshifts and deceleration. I know this is the typical first sign of bad synchros. When I rebuilt, I used parts which I have since learned stand a good chance of being inferior foreign made junk.

As the result of a previous thread, I bought an NOS synchro unit to have on the shelf. Even though I have these parts, I'm not thrilled to have to pull the tranny and rebuild right now. A few questions:

1. Am I going to do any additional harm driving it as-is this summer, even if I have to occasionally hold it in second gear?

2. Could the problem possibly be due to worn poppet balls/springs? I never changed those out during the rebuild. If those are the culprit they'd be a lot easier to deal with right now. Is it possible tell by visual inspection if they are shot?

3. Any other suggested "easy" fixes or am I only avoiding the inevitable task? I've read a few posts about horseshoe shaped shims that were available years back that might help. Any other suggestions?

I'd much rather tear things apart in the winter than have to rip into it this time of year.

It could also be to much end play in the gear assembly. Did you set the end play when you rebuilt the tranny? If not that may have caused it to wear and start jumping out of gear.

You can wait until winter if you only drive it in good weather.