I think my diff is clunking... are these the right symptoms?

[Redfox]

Hey guys,

Just wanted to check what the clunking noise is in my VT S-pack. I am guessing my diff is clunking or something because when I accelerate from a stop and then come off the gas to say slow down for a speed bump, I can hear a clunk or some sorta thump come from under the car. I'm guessing that this is the diff clunking in the rear, but I'm not certain. Could it be anything else? If it is clunking, what is the best way to fix it (apart from a new diff)?!

Cheers, Chris

[blacksv8]

Redfox, sounds like diff chatter, a common problem in all holden diffs.
get yourself 2 bottles of diff oil additive and all should be fixed. plenty of info under
"diff chatter" using the seach function.


cheers

[Redfox]

Thanks mate... I will have a look! :)

[Sid447]

From,

What you're describing, it sounds like you have play in your driveline somewhere;
either txmsn, propshaft, diff or driveshafts.
You need to get the car up on a ramp lift and have it checked by someone that knows what they are doing.

Diff chatter normally happens at low speed doing a full lock turn (i.e. like turning into a parking space or doing a u-turn; and it's not a "clunk" ........it's a "chatter!" ).

[VTSS195i]

My VT SS used to do the same thing..... A diff specialist advised me of a Castrol diff fluid to use and it fixxed the problem straight away!!

[Rt!]

its pretty common for VT V6 diffs to cluck everywhere isnt it :P
mine certainly did.

[Redfox]

Sid447, i think you are right. I have read most of the threads on diff chatter and I don't think that is the problem I have. It sounds like something loose in the drivetrain that clunks everytime I come off the power. It's as if the back part of the drivetrain still has the inertia to keep spinning whilst the front part has slowed down because I came off the gas. Is it possibly the rear uni? I will check it soon. Could be the tranny, but I'm not too sure. I'll speak to a mechanic next time it goes in for a service.

[applesLS1]

hey guys i have a wh statesman with the same sort of problem when i pull up at a set of lights there is a small donk sound like a bit of a slap coming from the rear of the driveshaft could this just be a uni joint or worse??

[Drewie]

I would say it is the diff itself, my VX SS had diff chatter at very low speed when turning in carparks etc, but it also had that slight clunk as you came to a stop at the lights. I had Holden also replace the pinion seal when they changed the diff oil and added the additive as I had read an article that the early pinion seals were not compatible with the additive, it was a Holden Technical Bulletin I read, any way what I am getting to is that to change the seal they had to undo and remove the pinion, I asked how they got the pre-load on the pinion right and they said we mark the nut etc and when we re-assemble we re-align the marks and give it just a touch more tension on the nut.
Well obviously the additive fixed the chatter, but the clunk has completely gone, dead quiet every time I come to a stop, so in my case I reckon it is because there is a bit more pre-load on the pinion. So I would say that the clunk in my car was due to back lash in the diff.