LSD bumping

[bluestarion]

Hi,
It seems the suspension is ok and no obvious issues with bushes.
The axle tramp is intermittant.
Sometimes the LSD appears to be not working i.e.
- one wheel will spin (like a non LSD).
- I will get axle tramp
- LSD operates nicely and the back end slides out :)

Really odd.

Matt

[redzone]

do you have the correct oil in the diff??

[JA83]

hey mate its lorne with the red staz. another hobart member is trying to organise a cruise on here if your interested?

[bluestarion]

do you have the correct oil in the diff??

I hope so :)
That would be worth checking and re-doing though.
Any recommendation on a good oil and/or additive?
Matt

[redzone]

castrol LS90 i think is the original recommendation, any proper LSD oil is the go though.

[MrBishi]

I still can't see a non-functioning LSD causing axle tramp.
Stranger things have happened though...

[bluestarion]

It 'feels' like axle tramp.
One explanation is that under certain conditions an oscillation is setup between the two rear wheels due to the torque transfer in the LSD. The result is and on/off of traction for one of the wheels which feels like axle tramp.
It may be a combo of things (bushes, Konis set to soft and the oil!).
Oil is easy, Konis will be adjusted at next service and bushes well I will have a good look.
Matt

[VR4RION]

Have had a similar problem in the past, turned out to be the rear guards bouncing of tyres on take off, soft rear end causing it to bog right down under power. So maybe check for rub lines around the most outer edge of ya rear tyres. Worth a look!, took me a month to finally pick up on it.
Good luck

[Sargeant_Khan]

Hey man, I have had this happen to me when I have had
Loose torque tube mounts at diff (the looser they get the worse it feels)
Loose diff bolt mount (this is not on and off)
And rear left axle needed recondition. (intermittent)
:beer

[bluestarion]

Well since the last post I have tightend up the diff and torque tube mounts (made a slight improvement), checked and lubricated the rubber bits (actually made it bit quieter) and changed the oil.
Unfortunately it still does it (intermittently).
I am going to change it out for the spare (non-LSD) diff I have to check for sure.
Will update with outcome.
Cheers
Matthew

[TOMSUN]

My money is on your rear shocks are not quite right.

Are there places you can take your car and the analyse your suspension. Like dyno tuning for shocks? Can they do it wirh the shocks still in the car? Spring rates and shock settings might not be compatible?

[OLD FART]

Fulcrum have a shock dyno but they have to be off the car
Pedders have a gizmo that shakes the carand prints out the result so you can see if both sides are the same

[thrash]

would you know how much pedders charge for it? or, what to ask for to get that specific test done?

[OLD FART]

would you know how much pedders charge for it? or, what to ask for to get that specific test done?

I had it done as a part of their $14.00 suspension check a few years ago

[bluestarion]

Alright.
Had the diff swapped out for a non LSD.
Interesting results......
Feels a hell! of alot tighter and is MUCH quieter. Sooooo I reckon the LSD is a bit dodgy and will send it to the hospital for repair.
It still didn't fix the axle tramp but it feels different.
Mechanic reckons it is to do with the valving on the Koni's.
Quite pissed off considering I sent them away for reconditioning specifically to resolve this issue so will see how it pans out.
Spent enough on problem solving now.......
Matt