mscotese

Hi,

My 4th gear synchro band popped up out of its groove and blocked the gear from being shifted into. I took the top cover off the trans and tapped the band back into place with a small hammer and screwdriver. Now it shifts into 4th on the bench but I assume it will come right out again unless some parts in that area of the trans are replaced.

The trans was rebuilt with new bearings and synchros about 20,000 miles ago and I plan on selling the car in the spring so I just want to correct this issue.

Any idea what parts I should replace to correct this issue?

Thanks, Mike



Background:
I have an 82 928 with manual trans and during a September Road America track day I was coming into a corner at approx 100 mph in 5th gear and instead of just braking like I had been doing all day long I tried to down shift into fourth to save the brakes which were beginning to fade and the shifter seemed blocked and it would not travel into 4th gear. All the other gears worked but now sometimes with some extra force required. I limped home and when I removed the trans and took off the top cover I could see that the 4th gear syncho band had raised up out of its groove and jamed there. I tapped it back down into its groove with a hammer and screw driver and now it shifts into 4th on the bench OK. I will disessemble the trans and replace for sure the 4th gear synchro band but what else should I replace to help insure the new band does not do the same thing? Mike

GregBBRD

You need someone who knows what they are doing, instead of the last "rebuilder". There's 2-3 people, in this entire country, that know what they are looking at, inside these transmissions. Unfortunately, there's probably dozens of people, too stupid to say "No", that can take them apart, screw them up, and put them back together....with pieces scattered in various incorrect positions.

Over 50% of my transmission work is "fixing" what the previous guy screwed up.....on transmissions that have been together for very short periods of time. Where and how the pieces get installed back inside is hillarious....it's like a shop version of "Standup Comedy".

And the really bad thing for people sending me these transmissions....it is always more expensive to fix what some idiot did, than it would have cost to do it correctly, the first time.

Your problem:

When all of the dimensions, inside the transmission, are set up correctly, it is impossible for the synchro to "pop up" from under the engaging teeth on the gear...unless the teeth are actually completely ground off, allowing the synchro to expand.

And yes, it will occur again.

hacker-pschorr

Wow, that's amazing. I didn't realize the three people I know in Wisconsin were that specialized in these transmissions

Lizard928

I've seen the engagement teeth worn down enough to let the synchro fall out....

GlenL

Who and where?

GregBBRD

Not on 4th gear.....