Diff on Ground

[AdamAnt]

Hi,
I have a problem.
I have Super Low springs in my VY2 SV8.
When I have even just one person in the back and a go over a small-medium bump in the motorway (crappy NZ roads) the back drops down as you would expect after the bump after which there is a loud bang when the diff hits the ground.
When the back of the car is full, it does it on small bumps at 50ks...
My question is can the diff be raised or have some guard installed or does the car need to be raised???
Thanks
Adam Ant

[Boonz]

if the diff hits the ground then you must have no springs in the back at all cos it should be sitting on bumpstops... so id be checking if they are still connected to the chassis before anything

[Reaper]

if the diff hits the ground then you must have no springs in the back at all cos it should be sitting on bumpstops... so id be checking if they are still connected to the chassis before anything

Close.... If the diff hits the ground then the wheels must have fallen off and the solution should be self evident

Reaper

[AdamAnt]

nah, definately not hitting bumpstops and the springs are definately in, i dont think they are captive at full extenstion though, if you say it cant be the diff then what else could it be because it definately sounds like it and the bottom of the diff houing has some large scrape marks along the bottom
thanks
adamant

[Boonz]

it would be the bumpstops hitting... the diff would have scrapes from wogcrawling over speedbumps cos when you go on angles it drops the diff down when the first wheel is on level ground

[Reaper]

Exhaust, subframes, anything else under there..... Look for the bit with the dent.

Reaper

[AdamAnt]

oh really, would that also make the huge loud noise???
also another problem which may or may not be related, when giving it some boot around corners i heard no huge noises but apparently there were sparks coming out the back of the car...

[Boonz]

that might be the exhaust

i suggest you raise your car up and use higher load rated springs so it doesnt bog down when you give it some boot

[andyman]

dosnt the exhaust on the vy's loop over the rear suspenion and the drive shafts, theres some pretty close parts there so i would check out if the exhaust has been hitting with the suspension

[Reaper]

Can you post a pic of this car? Sounds very low to me.

Reaper

[AdamAnt]

i currently have superlow king springs, what would you suggest???
also am going to be havn approx 120kgs of sounds in the boot soon, do you think some low kingsprings would do the job?

[Reaper]

i currently have superlow king springs, what would you suggest???
also am going to be havn approx 120kgs of sounds in the boot soon, do you think some low kingsprings would do the job?

120kg is a lot of weight to cart around all the time.... I'd look at an uprated spring rate myself.

Reaper

[AdamAnt]

the problem is that it dosent look very low, but something must be at fault???
could it be the exhast hitting either the ground or some other part of the rear suspension/frame etc etc

[AdamAnt]

i dont know much about springs etc.
what would be a good one to go for?

[Boonz]

i wouldnt use kingsprings for heavy duty purposes.... i know pedders does a set of lowered heavy duty springs.
i just dunno what height it sits at

[AdamAnt]

oh really thanks, how would i go about getting pedders springs in New Zealand or would something like dobi make a similar spring???
thanks
adam ant

[Boonz]

oh.... ask a suspension place if they do heavy duty springs cos i didnt see that your in NZ

[AdamAnt]

ok thanks heaps for all your help.
really appreciated...
thanks
adam ant

[Calaber]

nah, definately not hitting bumpstops and the springs are definately in, i dont think they are captive at full extenstion though, if you say it cant be the diff then what else could it be because it definately sounds like it and the bottom of the diff houing has some large scrape marks along the bottom
thanks
adamant

It could be that the springs are about 150 mm too short, too. Brother, when the arse of the car starts bouncing on the tarmac, get rid of the springs and start again.

[Nobody Actually]

too low+ irs= bad for diff

[davey g-force]

Heaps of people have super lows on their VY's and don't have any such problems. Sounds like your problem is related to something else, as suggested.

Get it up on a hoist and have a good look...

[adamc11]

Could someone with superlows post some pics so i can see how it looks. Thanks.

[VLDavo]

could be the muffler or something hitting the ground or something hitting the floorpan .. just crawl under and see if anythings dented or scratched