dubaitacker

possibly for me i run a 335 x 30 x 18 rear tyre so i didnt want to put the 4.10 gears in



i would have a simular gearing with that tyre to running the 4.10 gears on a stock size wheel and tyre

427V8BB

dubaitacker

I haven't really booted the old girl yet to scared shyteless about the valve guides with the wigge test results.....


Im not running any mods to the engine that I have worked out yet, think its standard with a tune. If it is standard the tuner thinks it would be around 560hp at the engine as that's what his car made with the same tune. Though we have 98 pump gas at every fuel station so I guess its has a bit of advance tuned into it as I was told to only run that fuel.


Had a few half hearted attempts and I would have to say its going to be have considerably more push into the seat than before, and its is going to drop right into the middle of the sweet RPM range on the upshift.

blkscls1z

Came in earlier this week. Planning on putting it in next Monday.

REDZED2

That's not a C6 Z06 diff though. Unless I'm blind. 3.90s should pull hard anyway!

blkscls1z

It's hard to see the top in that pic, but it is in fact a C6Z diff. I removed the diff cooler. Don't need it for drag racing.

xowhitegenxo

When I lived in bahrain I remember getting the Mumtaz pump gas and it was 98. I had my motorcycle with me at the time and it ran really well even in those hot summer days/nights.

jimbob8915

On a Z06 is there a different oil or modifier necessary for break in?

AzDave47

no, they are separate units with the tranny bolted to the dif, but separate cases. They also take different fluids. The dif cooler uses the cool tranny fluid from the radiator to cool the dif fluid, but again the fluids are on their own side of the heat exchanger.

Many of the car mags call it a transaxle, but it is not a true transaxle.

Mike44665

No. Better research this before you tear into it. It is quite a job, you will end up with the transmission supported and sliding the diff off of the output shaft to the rear of the car. Harbor Freight lift table is the way to go. A floor jack just won't get it.

Pb82 Ronin

Subbin'...I need 3.90's in my life.

redbird555

Just wanted to bump this thread. I'm having my 3.90s installed by a local Corvette shop and I was wondering if those of you who had the installs done replaced the pinion bearing assembly?

If the hearings are in good shape my guy says they'll be fine to reuse which I know is normally ok but just seeing what others did

Mike44665

The pinion bearing is already assembled from GM. It is two opposing tapered rolling bearings with the correct spacer calculated and installed. This setup allows you to torque the nut the crazy torque required. If you have it in your hand, or they have it in their hand, considering the cost to get to this point, I believe it would be a very big error not to replace it now.

My $0.02.

Mike44665

Here is a picture.

redbird555

New pinion bearing on order... I cant find the nut however in stock anywhere. I understand that many say reusing the old nut is fine. Can anyone confirm? In pics I've seen it looks just like a metal nut so I don't see why not?

No Lemon

Is there a install kit with bearings and whatever else comes with it available or do you just piece it together? I called Summit and they to call the dealer?

Mike44665

This is the answer you're looking for.

It MUST be set up correctly or you'll fry the bearings right now. This is why it is an assembly, GM removes the chance of and error and disaster. You can't over tighten the nut and hurt the bearings with the GM assembly.

redbird555

Don't mean to be rude but I'm not sure if this was answer to me about the nut or lemons question.

In the rebuild procedure I have I the gm manual it makes no mention about replacing the nut just to inspect it upon removal for any issues. I assume that means it's good to reuse?

Mike44665

I apologize for the confusion. I should have stated the reply was for "no lemon". You can't buy the bearings and put them in the housing, it even states that in the manual.

As for the nut issue, these things are torqued to 370 foot pounds. As long as it come apart with no issues. When something is that tight, obviously there is a lot of pressure of the threads. If the threads start to tear or snag the nut is useless. I went with a new nut as to avoid this if it did occur. When spending this amount of money to change gears, a few more dollars becomes irrelevant.

In addition, after having the 4.10's in for all last summer in Ohio, it makes the transmission so much more usable, all six gears. Can't wait to get on the road this year.

548chevelle

Just ordered my 3.90's. I've done a few regulars rears- Ford 9", Dana 60, Chevy 12 bolt - but this one looks really daunting. I'd like to see a vid on doing it. Anybody know of one?