Doug Nash 4+3 rebuild

[rcourtem]

Hello:

I just dissembled my Doug Nash O/D unit off my '85 Corvette. Looks like
it's been rebuilt before, has the newer style waffled clutches, thrust
washer, etc. The direct clutches (5 installed) were all about 0.060"
thick, the O/D clutches (5 installed) about 0.090" thick. The steel plates
all look good, as does the annular bearing (SKF 61912). One strange item
is that only 5 waffled direct clutches were installed, although there were
6 steel plates (not counting the special thrust plate), two back to back.
Assuming the direct clutches were originally the same thickness as the O/D
clutches, I assume this is why the car was slipping in reverse. Nothing
seems broken, all I can see wrong is possibly the worn direct clutches.

A few questions for the group:

1) How long do these units last after a rebuild? I'm hearing 30K miles in
some places!

2) Anybody know the thickness of new clutches?

3) I'm looking at Eckler's soft parts kit, about $140, stock #35651. Any
experience with their kit out there? I've ordered from Eckler's before.

4) any other thoughts?


I've got the Helm Factory manual and David Fulcher's excellent online
article from the Corvette forum for guidance.

Thanks,

 

[Ken]

Welcome To The Corvette Action Center rcourtem!

Cool. I wish I had the balls to tackle a transmission rebuild.

I can't answer your questions about disc longevity, thickness or anything else about the insides, but have you talked to Paul at The Gear Zone or paid a visit to 4-Speeds by Darrell? Darrell started rebuilding the DN 4+3 a little while ago, but the last I knew Paul at the Gear Zone was concentrating on another trans and not the DN anymore.

Good luck! And welcome to our little "Corvette Club".

 

[LarryBible]

All I can say is that if it only lasts 30,000 miles, it must have been a 1/4 mile at a time.

Except for shift solenoid, and a micro switch at the base of the shift lever, mine has had nothing but preventive maintenance for 112,000 miles and is still in great condition. I wish I could say the same for the rest of this troublesome beast.

Good luck,