Why will 4.08s not fit in a diff. from an Auto?

Ivoidwarranty · 04-16-2013, 06:24 PM

Can anyone tell me why it is that 4.08 gears will not fit in a rear end from a car with an automatic transmission?

Is this some holdover from the early 350Z/G35 days or is there a more concrete reason?

What is the difference in the housings?

chrischhorn · 04-17-2013, 02:29 AM

Quote:

Originally Posted by Ivoidwarranty

Can anyone tell me why it is that 4.08 gears will not fit in a rear end from a car with an automatic transmission?

Is this some holdover from the early 350Z/G35 days or is there a more concrete reason?

What is the difference in the housings?

Its not the housing. Its the Gear ring that bolts to the diff. The auto's have bigger differentials then the manual transmissions if I'm not mistaken and seeing how the 4.08 gears are taking out of a manual transmission frontier, it just won't work. Comparing the difference between the auto and manual quaife LSD, it looks like the bearing/crown wheel is where it differs between the auto and manual trans. If you swap completely to a manual transmission rear end (the whole pumpkin) and put the 4.08 gears in that or swap the gears and the differential at the same time it should work. You will need to swap to a 6MT differential though to make it work for sure.

So you can see, installed in a auto but with a manual trans VLSD

4.08 Gear Install (7AT) Review

Ivoidwarranty · 04-17-2013, 10:27 AM

Thank you.

-So the housing are the same from autos to manuals.

-I can probably get away with an automatic housing as long as I buy a manual differential.

I didn't know there was a different Quaife for autos and manuals.

Thanks again.

matcop · 04-17-2013, 10:31 AM

Hi Guys,

You might want to talk to Sebastian at Specialty Z. He has done a few automatics and that is next on my list of things to do (hopefully in the next month)

These guys know there stuff.

(818) 703-6272

Ivoidwarranty · 04-17-2013, 10:39 AM

Quote:

Originally Posted by matcop

Hi Guys,

You might want to talk to Sebastian at Specialty Z. He has done a few automatics and that is next on my list of things to do (hopefully in the next month)

These guys know there stuff.

(818) 703-6272

What are your plans? New rearend or reuse your exsisting and get a new differential?

04-16-2013, 06:24 PM	#1 (permalink)
Ivoidwarranty Base Member Join Date: Nov 2009 Location: Nebraska Posts: 59 Drives: 08 G37S Rep Power: 15	Why will 4.08s not fit in a diff. from an Auto? Can anyone tell me why it is that 4.08 gears will not fit in a rear end from a car with an automatic transmission? Is this some holdover from the early 350Z/G35 days or is there a more concrete reason? What is the difference in the housings?

04-17-2013, 10:31 AM	#4 (permalink)
matcop Base Member Join Date: Jun 2012 Location: Montclair Posts: 68 Drives: 2009 370 Z Silver Rep Power: 13	4.08 gears 7AT Hi Guys, You might want to talk to Sebastian at Specialty Z. He has done a few automatics and that is next on my list of things to do (hopefully in the next month) These guys know there stuff. (818) 703-6272

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04-17-2013, 10:27 AM	#3 (permalink)
Ivoidwarranty Base Member Join Date: Nov 2009 Location: Nebraska Posts: 59 Drives: 08 G37S Rep Power: 15	Thank you. -So the housing are the same from autos to manuals. -I can probably get away with an automatic housing as long as I buy a manual differential. I didn't know there was a different Quaife for autos and manuals. Thanks again.