The track car is coming together and I got to drive it a bit.

I adjusted the clutch and clutch seems fine, there is no apparent drag on the clutch when fully disengaged.

1st, 2nd, 3rd grind horribly. Second and third evend grind during upshift, downshifting hurts...
Something get's in the way now and then and 2nd and fourth pop out while accelerating.

I think it needs to come out, but if anyone has a suggestion as to what I could try would be great.

My thoughts, questions are;
This is an old style tranny with no LSD, is it worth to rebuild for track / race use?
If I buy a new one, is this one worth anything?
How much is a rebuild?
A buddy told me he got some expensive steel synchro replacements? Myth or fact?

Thanks,

 

I had my gearbox rebuilt a few years back and have never been happy with it. fourth gear sticks and I am unable to get it out of gear when at a stop sign. Third gear is hard to get into at times. I have tried Redline and Royal Purple synthetics to no avail. I am currently running conventional gearbox oil because I am still not happy. Rebuilt was ~$2400??.

I would not rebuild your old gearbox but rather try to find a newer one. I don't think your old gearbox has any real value.

 

I'll go with myth since the newer synchro's (introduced in 85) do not fit the early boxes.
If he has a source for upgraded synchro's for the early boxes, I'm sure a lot of people here would be interested.

 

Is it G28/03 or G28/05?

 

The problem with rebuilding the early box is that most don't know how to identify what's worn. They often just get syncros, bearings, and gaskets when they really also need engagement teeth and sliders. The problem is if you replace all the wearing parts the cost gets up there.

 

I remember rebuilding my 84 gear box. it was a nightmare. it basically needed all the dog teeth gears, shift forks, things that only 928 was able to supply . in the end, it was fair at best. then, 5th broke.

One of the best mods ive done in the past, was swaping out the 84 gear box with the newer 2.2 from the 85s. But, the caveat is that you need the torque tube too. (i forget why, but you do)

mk

 

The late 1980-1995 5 speed torque tube is the same. Shift linkage was changed however. And when you break 5 th gear the input shaft it often bungs up the driveshaft too.

 

Sounds like I'll be buying a gearbox...
Thanks for the info.
Does anyone have a gearbox laying around?

I guess since mine isn't worth anything, I can just jam those gears in until it brakes.
I wanted to do a track day to find out what else comes up with the car.

"Is it G28/03 or G28/05?"

How would I know what I have?

 

Should be 28/05 trans numbers are stamped on the ribbing on the bottom of the case

 

G28/08 w/ LSD and TT for a $1K plus shipping.

 

I've rebuilt an early box and had good results (street use- not track use). There's a long and boring post about it if you do a search. I know Stan Shaw ran a properly rebuilt early box (from 928 Int'l I believe) in his race car for quite some time with good results.

So is it worth it? In my case, yes. I'm pretty happy with the results but my box wasn't as bad as yours sounds. Even starting with a decent box, I had to replace more than just syncros - bearings were all fine thankfully.

I would likely have upgraded to a newer (BW syncro) box if they weren't so scarce and pricey (and I like the lower final drive ratio of the early box too). It cost me just over half the price of a used BW box to rebuild but I did all the work myself and like I said, it didn't need a lot.

If you get a newer box and want to sell your old core, if the price is right, I'd be interested in it to disassemble and compare to mine (and possibly rebuild to have a spare).

BTW- there is / was a guy here in the northeast that rebuilds the boxes for $350 plus the cost of parts... at least that was the cost when I talked to him. I didn't use him because I decided to try it myself but I had heard good things about his work. If thats of interest, I can try to find his info.

 

Andre, if that is the newer style gearbox and works well, I take it today.
Can you give me some info what it is? I am clueless with this gearbox issue.
All I know my '91 GT gearbox had over 200k miles on it and shifted perfect in any gear.

So the one you have is similar to the box that was in my GT with different drive ratios?

That "82 gearbox is the worst I have ever seen and I have driven a few cars over the years...

 

Andre? give me some info on that gearbox please.

 

G28/08 is 83-84 US with the old style synchros and tall gearing.