au rear live axle SL suspension bottom out

[ben131185]

I've got SL king springs all round on my live axel au.
Rear sits slightly lower than the front.

Sometimes when travelling over speed humps or over bumps on the freeway the rear suspension seems to bottom out. It become more noticable after the lpg tank went in.

Has anyone else had this problem?

I still have the stock shocks in the rear, maybe its them that are bottoming out?

[mongrelEF]

Yeah, that'll happen with superlows Got rid of my own set years ago after bending my third rear swaybar! With a gas tank in it' you'll need to stiffen up the rear end a bit, a thicker swaybar or adjustable shocks will probably be your best bet. Either that or stick stage 1 springs in the back. I suspect the weight of the gas tank will probably pull the rear back down to stage 2 height anyway

[robbyj]

i have king spring super lows all roung my AU and it doesnt sit that low. I have 20's on though. I had 15" stockies on the rear a little while ago and use to scrape the mud guards everywhere. after i removed them it was all fine unless going down a steep gutter.

[blueoval]

The gas tank in the rear will make life harder with SL's. Did you tell the supplier you had a gas tank in the rear? I think you can get SL's that cater for lpg tanks from memory. Could be wrong. I would be inclined to swap what you have for these as they will be stiffer to cater for the extra weight. Alternatively, as mentioned, go to Kings Low, and let the lpg tank lower it further to SL style height.

[ben131185]

I've had the springs in for 4 or 5 years and the gas tank in for about 18 months.

[Cam]

What shocks are you running??

[ben131185]

I think I'll look into new lowered shocks and bump stops first and see how that goes, I need new rear shocks anyway. If that doesnt improve things I'll look at the springs.

It doesnt sit as low as Ultra lows so its either the bump stops or the springs need to be stiffer.

[ben131185]

Still running the stockies in the rear Cam, cars done 160,000 now, they've seen better days i think.

Front has Monroe GT gas, replaced at 95,000 when the SL's went in, and they're going fine.

Im thinking of either Lowered Monroe GT sport or Lowered Ultima shocks.

[ben131185]

Put in new Ultima Heavy Duty Lowered shocks today.
They're much bulkier than the standard shocks.
Went for a drive, seemed to feel a bit better ride.

Still getting what I though was bottoming out.

However when I was under the car I took a good look at things under there.
I've aways thought the exhaust and muffler hangs pretty low. It;s a 2 1/2" redback cat back system. I noticed there is a bit of a mark on the exhaust straight above the rear axle, It now seems as though when the rear end flexes downwards and the body and exhaust get lower the exhaust actually makes contact with the axle housing.

The rubber exhaust hangars look a bit tired also. So it looks like I'll need to have the exhaust tucked up a little higher and possibly some new hangars.

Has anyone else had this issue?

[Cam]

I had the exact same thing. After many months, and LOTS of cash spent fixing other stuff i thought i was the issue I finally found out that's what was causing it.. Took it to a zorst mob who for $50 tucked it up a lot higher, not had an issue since..

[WannabeXP]

There are a HD version of the superlows. I could have got them through my work(SCA)

I too put SL's all round in my car with gas and it handled like a 30 year old ford telstar with 600,000km's on the clock. I then went and put new shockers in to no avail. So i stuck to the standard XR springs i had.

I was just too tight to buy another set of springs.
Cheers Jason

[ben131185]

Originally Posted by Cam

I had the exact same thing. After many months, and LOTS of cash spent fixing other stuff i thought i was the issue I finally found out that's what was causing it.. Took it to a zorst mob who for $50 tucked it up a lot higher, not had an issue since..

Cam, do you know what they did to tuck it up?
Did they cut or bend the exhaust hangars?

The exhaust tip is pretty much rubbing on the underside of the rear bumper, might have to heat it and bend it slighly to allow the rest of the system to be lifted aswell.

[Cam]

They actually did both, mine is a 3" and there was a flange above my sway bar that was fowling, so they moved the flange and removed and relocated the hanger, and slightly twisted the rear section so it cleared the hold in my rear bar..