85vet

Looking to upgrade my rear and strange is asking for pinion offset. Is the pinion centered on the dana44 or is there an offset?
Thanks in advance.

WVZR-1

It might help to know what you're attempting to buy or have Strange build for you. What is it?

I don't know of a specific "offset" for any rear but in just very generic terms in a differential I'd think that "centered" would imply equal length axles and any "offset" would imply unequal length axles. If that's their question then the C4 is "offset" because the short-axles are of different length.

Are you trying to do a spool or something?

I'm quite curious.

If you're building a solid rear you need to tell them the housing is to be centered but the pinion offset. I believe I've read 1". All driveline/drivetrain for RWD is generally offset to the right side of the car.

85vet

I am having Strange set up an S60 rear with a spool and 3.54 gears. The measurements I have with a spare Dana 44 is an offset of .75 inch.
I am going solid and upping the motor a bit over the winter. Looking to run low 10's next year!!!!
I know 12 bolt would work but I like to be more on the safe side with little or no breakage.
Jim

WVZR-1

I just did this using axle lengths that I forgot I have and I got .77

The longer axle is 7.36 and the shorter axle 6.59 so your .75 is I'd say right there. I was going to measure a housing later today but I recalled I had some specifications from Dana.

85vet

Thanks for the input.
Strange has a turn around of 10 to 15 days on this so I hope fabrication will be complete by mid October to test car this year before modifying the motor.
Just for your reference the length- Axle flange to axle flange is 62.25"

WVZR-1

Sounds like an interesting project. Are your suspension members done yet? It would be interesting to see some snapshots of maybe the suspension components before you add them to the housing. Your S60 is done less all mounts? Plans for brakes?

rklessdriver

For 1984-1988 "regular" Corvettes.

I think all C4 ZR1's are the same as well.

I do know the 1989-1996 "regular" Corvettes are wider... the difference between the outer stub axles on my 84 and 92 is about an inch.

Good luck with the S60 conversion.
Will

WVZR-1

The 62.25 is for an '84 - '87 rear since he mentioned '85 if those are of the C4.

The change occurred in '88 and all from '88+ share the same flange to flange dimension which is larger. I had always heard 62" for the early and if measured without rotors maybe that's correct, the 62.25 with rotors on the hubs it would then be very close believe and I've never measured either early or late personally. I very well might one time just to know.

The +1" for the later is what seems to get mentioned most frequently but wheel offset differences don't seem to confirm that when used in calculations.

Maybe also he's mentioning the width of the S60 that he intends to use?

rklessdriver

I measured my 84 just for fun recently.... I have the car apart pretty often to check on the U-Joints, alxles and brgs so it was easy to do...

I went from the wheel mounting surfaces (outside rotor to outside rotor) - with no spring and jack stands under the camber arms to get everything level like ride height - Anyway I also came up with 62.25".

I have never measured my 92 and since I have stopped racing the car, I haven't broken anything on it in a while, so there has been (thankfully) no need to take it apart....

But I do have an old 92 outer stub axle laying around with a bolt broke off in it from an explosion and recently when I had the 84 apart, it popped into my mind that I could easily compare them.

Next time I have a chance, I'll actually measure the 2 different outer stub axles and see what the difference is.

I may also be doing a straight rear end (and Powerglide) after this season is over.... I hate to do it because the stock IRS has been good to me but I need to stay competitive in the class and the IRS (and TH350) are really starting to hold the 84 back.

Will

85vet

Not sure if I will be able to have pictures prior to install. A local race car fabricator will be doing the work. I WILL TAKE AS MANY PHOTO'S AS POSSIBLE.

The measurement given of 62.25 would be the new axle before rotors with a thickness of .25 or .125 each side. I measured the rear with the wheels off and hub on jack stand and jack stand on car mover (to allow settling of the independent rear). With rotors on the measurement is 62.50 (where wheels are currently located).
With the purchase of Strange's pro race disc brake setup we know the rotors are .125 inch (62.50 - (2 * .125) = 62.25 axle to axle. This will put the wheels in the exact same location they are currently in.