Odd grumbling/grinding/crabbing sound from rear left

[Manaz]

Hi all,

I've noticed a few times lately that when I enter a driveway (generally a left turn into the driveway) that I get a weird grumbling/grinding noise and sensation from the rear left as the wheel hits the driveway. It feels a bit like 'crabbing' in an older permanent 4WD vehicle if you've ever experienced it, or a bit like the rear brake is being activated (with ABS triggering). It isn't all the time, though it's generally repeatable if I want it to happen.

Turning VDC off seems to minimise/eliminate it, so I've been wondering if it's not related to the VDC/ABS system. There's no error codes in the ECU (and haven't been for ages).

As I understand it, the R180 diff is in the post-FL GT Spec.Bs, but has an open centre (or so I thought, so I shouldn't be getting lock-up behaviours). I never experienced anything like this in earlier 4Gen GTs or my 3Gen RX Liberty.

The other thing I've been wondering about is whether it's related to the auto gearbox and centre diff, or perhaps the rear diff. The box has 92,000km on it, I was considering having it serviced at the next full service (fluid drained, filter replaced, etc), and I do have a set of needle bearings that need to go into the centre dif anyway.

Has anyone else experienced this? Is this normal in a post-FL auto GT Spec.B, or do I need to be worried?

[owen]

What you're experiencing is centre diff binding. They're about $800 from Garage 88 and cost about $200 to fit. Another $100 for fully synthetic trans and diff oils.

[Manaz]

What you're experiencing is centre diff binding. They're about $800 from Garage 88 and cost about $200 to fit. Another $100 for fully synthetic trans and diff oils.

Yeah, this is what I was worried about. I'll give Michael a call...

[Manaz]

OK, and I've had a chat to Michael. He's done plenty of centre diffs for the 6-speed cars, but none for the auto - and he reckons I should look elsewhere to see where it may be.

I might do an auto transmission fluid drain/flush and see if that has any impact. The car is due for an ATF inspection at the next service anyway, I can't see there being any harm in me checking it a few thousand kms earlier...

[senator]

Rear diffs are known to leak on the GT’s, so have a close look.

Also check the wheels bearings another known issue with the GT’s

[owen]

Sorry. Retard moment. Yes, centre diff is common on manuals. Never heard of one go an auto.

[Manaz]

Rear diffs are known to leak on the GT’s, so have a close look.

Also check the wheels bearings another known issue with the GT’s

I shall take a look, thanks.

If it were a wheel bearing, I'm pretty sure I'd hear it at other times. And I just drove into the driveway earlier today, and it was much worse - the whole car was shuddering.

[Newbie GT]

Rear diffs are known to leak on the GT’s, so have a close look.

Also check the wheels bearings another known issue with the GT’s

I shall take a look, thanks.

If it were a wheel bearing, I'm pretty sure I'd hear it at other times. And I just drove into the driveway earlier today, and it was much worse - the whole car was shuddering.

To much hard driving rob ?

[jslayz]

Sorry. Retard moment. Yes, centre diff is common on manuals. Never heard of one go an auto.

dr20T had a mate pop his center diff in his auto......

J

[Manaz]

To much hard driving rob ?

Hardly.

[Manaz]

Sorry. Retard moment. Yes, centre diff is common on manuals. Never heard of one go an auto.

dr20T had a mate pop his center diff in his auto......

J

I've heard of people popping them (specifically the needle bearings) by stalling them up and launching. I've never done that in mine. That said, I do have a replacement set of bearings (the brass ones that were done as part of a group buy on legacygt.com ages ago)

At this stage, I'm going to see if a full fluid and filter replacement does the trick.

[Newbie GT]

Rob had this on my boat trailer was shot right hand bearing .. Just a thought

[Manaz]

Rob had this on my boat trailer was shot right hand bearing .. Just a thought

I'll get the bearing checked.

[Manaz]

Hmm...

The noise/feeling is getting worse. The whole car shuddered as I entered my driveway today. I can reproduce it entering a left or right driveway now, and am about to pull the ABS fuse to rule out an ABS issue (I can get it to do it with DSC off).

[Manaz]

Hmmm,

5 attempts with the ABS fuse pulled. No grumbling/lurching.

About to try with the ABS fuse in again. I'd love to do blind tests, but I don't have anyone around I can get to help...