Front Diff Broken

[Jkiwara]

Hey guys

I own a r32 gtr 92 Front diff has just gone few teeth on the the diff completely broken of pinion in bad shape to. Have no idea how it has happened. Mechanic I have taken it to has said it looks like I have been drifting(was not the case have never driven the car at all in that way) things I noticed before the diff went. Front torque gauge was engaging constantly. Would be max just cruising at 80kms,also started slightly vibrating at same speed. Tires on wheels are all the same size, no red flashing lights on atessa ecu, 4wd light been on twice since I've owned the car (4 mouths) any help would be much appreciated. Hoping to get it back on the road before Xmas. Please help!!

[Sinista32]

4mths ? So you have no idea how it was treated previously...

If you don't trust that mechanic ( I don't know why not) ask a 2nd mechanic

from your gauge reading it maybe that you have been in 4wd constantly

- many launches ?

when it was up on the hoist you would be able to check yourself

if the front diff is like that I don't like the chances of your rear diff being in good shape either

Edited December 9, 2014 by Sinista32

[Jkiwara]

No idea was fresh import from japan so who knows. car looks in pretty tidy condition. Mechanic suggested had been drifting due to the rear tires being feathered. Never launched the car before haven't even really given it some stick. Would it be normal to be constantly running 4wd? Pretty sure there is no type of manual controller of some sort for it? Cheers.

[datsun_1600]

This happens when the G sensor goes. Power is sent to the front on even the slightest movement. I've played with the sensor a fair bit and have seen this happen. Check out my thread on re-calibrating it (or sounds like yours might be too far gone). It's probably flogged out both diffs, and maybe the transfer case too. It would be like driving a Patrol in 4x4 on tarmac, diffs will only last a very short time.

Sorry to hear about this. I might be wrong, just my 2c. Sounds like two new diffs at the very least and probably a new transfer case. Not too expensive to fix, but might take weekend or two to fix it (if you are doing it yourself)

Jeff

Edited December 10, 2014 by datsun_1600

[MrStabby]

I would have thought that an attessa problem would just wear out the transfer case prematurely. How could it stuff the front diff? Why would it stuff the rear diff? The rear's always on anyways.

[datsun_1600]

I would have thought that an attessa problem would just wear out the transfer case prematurely. How could it stuff the front diff? Why would it stuff the rear diff? The rear's always on anyways.

Something has to give. The average wheel circumference between the front and back of the car will never be "exactly" the same. If the clutch pack is fully engaged there will be a difference in wheel speed between the front and back of the car. Either the wheels spin just ever so slightly, or the clutch pack slips. Either way there is a HUGE loading on the front and read diffs - let alone the drive shafts, CV and uni joints, tail shaft, transfer case drive chain etc. Normally a diff will just left go. The weaker of the two is the front diff so in my experience that would be the one that blows. I'm sure the rear is showing signs of wear. That is why you never ever run a run a 4x4 (with no centre diff) on tarmac, not even for a second.

Edit - or maybe he got lucky and everything is ok, just the front diff blew. As an engineer I would have to pull it down and rebuilt it, just to put my mind at ease lol.

Jeff

Edited December 10, 2014 by datsun_1600

[jiffo]

If the workshop is any good they should be able to trace the damage trail.

I agree with datsun_1600, car has spent too much time being driven in constant 4X mode.

I'd suggest she badly overheated the front diff, pinion bearings collapsed causing hopeless gear mesh then…..

Vibrations OP noted could have been the front propshaft flogging about on rooted pinion bearings or the unis. may have had it.

Driver should have pulled the fuse (it's a 32) and then investigated properly.

But it really was tilt tray time, I'm thinking damage was done by previous owner.

New owners of these complicated old cars need to fully understand the systems they've bought into.

A torque gauge going nuts for no reason should be a red flag, likewise ANY driveline vibration.

Checking tyre size means exactly that, tape measure and note circumferences not simply reading side wall markings.

I'd certainly be checking the front and rear shafts, back diff and transfer case. And there's all the half shafts…...

Could get expensive as the ATTESSA fault still has to be identified and sorted..