Front vs. Rear Diffs

[JordanTr]

So pops and I have discussed that the front diffs people use from the pickup trucks likely have reverse cut gears since the tooth loading in the diff is opposite to a rear diff. Yesterday I had the F160 (Yes, Nissan calls it an F160, F for front, R for rear) diff out of the front of my Skyline GTR. Sure enough, gears are cut opposite to an R160 from a 510.

While a front diff works in the rear, it is less than optimal since you are loading the back side of the teeth at higher loads/speeds than they were designed for. It's like driving 80 mph in reverse.

Pics. Discuss. Mull over your coffee.

F160 left, R160 right

[datzenmike]

Since we only got (R)-180s in our 720s this should more than compensate for this. I'll compare the pinion part numbers when I get home. Good point though and something to think about.

[JordanTr]

I thought 1 version of s12 had an r180 and the rwd Maximas had R180s as well? Neither easy to find or LSD obviously.

[510rob]

mind blown

[James]

^^Exactly^^

[Sealik]

720 R180 front diff....gears cut the same as the R160

[510rob]

mind now unblown... ...phew, that was a close call!

[datzenmike]

R-180 crown and pinion gear sets for the S12 200sx non turbo and the '83 and up 720, both 4.11s are the same part number.

38100-U3000.... 3.364
38100-U3100.... 3.545
38100-U3200.... 3.70
38100-U3300.... 3.889
38100-U3400.... 4.11.... used on front of '83- 720 and rears of CA20E S12s.
38100-U3500.... 4.375
38100-U3600.... 4.625


I think it's safe to say that the R180 is an R-180. None of my info says anything about F-180s in any Nissan. It's interesting news though.

[JordanTr]

Good, the sky isn't falling after all.


I believe xterras and pathfinders have special front cut gears as well. On the r+p page it says fwd only. That's an F200 I believe. Looked for the page today but couldn't find it back.

[McShagger510]

While a front diff works in the rear, it is less than optimal since you are loading the back side of the teeth at higher loads/speeds than they were designed for. It's like driving 80 mph in reverse.

That was the reason those Clanks over at IWE gave me after they setup my front diff R180 and it howls like a banshee. Fuckers.

James

[Sealik]

"That was the reason those Clanks over at IWE gave me after they setup my front diff R180 and it howls like a banshee. Fuckers. "

James
............................................................................................................

Setup????

As in pre-load?

[McShagger510]

Setup????

As in pre-load?

No, they installed a NEW Power Brute LSD into the '80 truck diff I had. 200lb breakaway I believe.
I was changing out the oil in the diff one day and saw something inside that caught my eye. I dropped the rear suspension down a bit to remove the cover and found this rattling around in there! Good job boys!

James