LSD bumping

bluestarion · Post by **bluestarion** » Thu Mar 18, 2010 7:39 pm

Hi Guys,
Under hard acceleration and when I loose traction it feels like the rear suspension is bouncing.
Consequently I had the rear (and front while I was at it) suspension redone (KONI).
Well it still happens.
Could it be the clutch plates in the LSD?
Has anyone else had a similar experience.

Can anyone recommend a company that can help if it is the LSD?

Frustrated
Matthew

JDSTAZ45 · Post by **JDSTAZ45** » Thu Mar 18, 2010 8:09 pm

Yeah, I've had this problem in one of my cars under hard cornering. I would assume something is going on with the lsd. Maybe a little tight?
Perhaps try putting in an additive in the diff oil and see if it improves. Otherwise, there's always a rebuild. I'm pretty sure any reputable diff place can handle a starion diff!

RiceThief · Post by **RiceThief** » Thu Mar 18, 2010 8:18 pm

Have you checked the rear subframe mounts and the diff mounts? The bumping that Jstaz45 was refering to ended up being a loose swaybar mount, assuming he is refering to the gsrv.

JDSTAZ45 · Post by **JDSTAZ45** » Thu Mar 18, 2010 8:24 pm

RiceThief wrote:Have you checked the rear subframe mounts and the diff mounts? The bumping that Jstaz45 was refering to ended up being a loose swaybar mount, assuming he is refering to the gsrv.

Actually I was!! :) Good to hear that was sorted!

thrash · Post by **thrash** » Thu Mar 18, 2010 11:39 pm

you're not just talking about axle tramp are you?

Adriano · Post by **Adriano** » Fri Mar 19, 2010 6:56 pm

Mine doesnt xle tramp at all

thrash · Post by **thrash** » Fri Mar 19, 2010 9:50 pm

neither does mine :D

but his might be, if he doesn't know what it's like?

bluestarion · Post by **bluestarion** » Mon Mar 22, 2010 9:23 pm

If you mean a repeating bump under hard acceleration (and traction is lost).
Then yes.
It is mainly on the passenger side. I haven't been able to make it 'bump' on the drivers side.
I will have another look this weekend.
Any other suggestions would be welcome.
Matt

Post by **TOMSUN** » Tue Mar 23, 2010 8:28 am

That will be a dead shock absorber

Nosaki Faki · Post by **Nosaki Faki** » Tue Mar 23, 2010 10:33 am

TOMSUN wrote:That will be a dead shock absorber

Yep gauranteed!
Mine was the same until I modded the rear shocks.

thrash · Post by **thrash** » Tue Mar 23, 2010 11:19 am

he did mention he had his suspension redone..

i still agree with the others though.. it sounds more like axle tramp than a diff issue.. perhaps get a second opinion from another suspension shop and see what they say? maybe one of your konis wasn't installed right, or if it is adjustable, it might be too stiff/soft

bluestarion · Post by **bluestarion** » Tue Mar 23, 2010 8:05 pm

Hmmmm
I would be disappointed if it is the shocks. All of them were redone at a reputable place in Melbourne......
I might get a second opinion.
I have a spare diff (non-lsd) so it may be easier just to swap it out and see......
Cheers
Matthew

Post by **Alspos** » Wed Mar 24, 2010 7:41 am

A few things you may want to try before you start swapping diffs.

Does it only do it when you turn and add power? Does it do it in a straight line? Does it happen if you spin on gravel or grass?
Can you repeat the process, perhaps you could video it and watch if axle tramp is happening.

How old are your tyres? Tried another set to see if it's an issue?
Have you looked at the diff mounting bushes that attach the diff to the rear cradle? They look like big rubber blocks. Checked the torque tube mount bolts are tight?

Put the rear of the car on jack stands, put the hand brake on, start the car, first gear and ease the clutch so the handbrake just stops the wheels from turning. Do it a couple of times and while you do, have someone look underneath the car to see if things are moving or twisting out of place when the power is added.

Have you checked the CV boots etc around the half shafts? Checked the CV's to see if they are sticking or binding up. If you turn it may put enough angle on the cv to cause it to make a noise.

Just a few things that may shed more light, and save you swapping diffs.

MrBishi · Post by **MrBishi** » Wed Mar 24, 2010 8:19 am

IMHO - it could be a plethora of things, the least likely is diff centre.

check all bushes (swaybar, diff, arms, crossmember)
check shocks (new konis 'should' be OK though)
check gearbox mount & engine mounts.

If none of the above then get back to us for more internet-crystal-ball problem solving.

How low is the car? What tyres?

bluestarion · Post by **bluestarion** » Wed Mar 24, 2010 7:15 pm

It's not lowered.
Thanks for the feedback.
I will check the obvious on Friday at the mechanics (I miss having access to a hoist)
A curious one. Did I mention it was there before the suspension was redone? so I agree unlikely to be the refreshed Konis.
I will report on progress :)
Matt

Austarion

LSD bumping

LSD bumping

Axle tramp?

Shocks?

Crystal ball gazing :)

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