Interesting one for you suspension gurus... R32GTR rear end

[Ronin 09]

I have a R32GTR, and recently replaced the stock suspension on the car with some coil overs.

When we pulled out the factory stuff, we found that the right rear strut had been 'spaced' between the strut top and the body mount with about an inch of aluminium disc spacers. The left rear was not.

I initially thought this could be a fix for a leaky strut, but when we replaced with the coilovers we found that the RR sat about an inch lower than the LR with the same strut / spring heights...

As a result, the RR is now wound up about an inch higher on the threads than the LR, - does this mean we now have preload on the RR side?

I have since talked to the previous owner asking if it has ever had a rear shunt or damage, and he said no - he's owned it since new. He didn't even know it had been spaced. I'm now waiting for him to contact the mechanic that was looking after the car to see if we can figure out what the deal is.

Which leads me to my questions-

1. What may cause this? Swaybar out? Whole cradle out? Chassis?

2. Who can diagnose / fix it? Will centreline be able to remedy it?

It is concerning me a little... as the car sees occasional track use and i don't want the balance to be out.

Cheers for keeping with the thread this long!

See these spacer thingies...

[SteveL]

Not good. Somethings bent, either chassis or suspension. One things certain - it didn't come from the Nissan factory like that.....

I worked at a panel beaters many years ago and saw similar things done with radius rods to 'compensate' for front end damage.

My brother's been a panel beater/mechanic for 30 years so I'll ask his opinion.

First thing you need to do is put the car on a hoist and very closely inspect all the rear suspension parts and rear subframe mounts - as well as all the chassis joints and panels at the rear of the car - for signs of damage. Also take out all the boot trim, spare wheel, etc so that you can inspect the shock towers and all the internal panels.

The only certain way to check the chassis is to use a chassis alignment jig, but that requires stripping a lot of the car, and would be a last resort.

[Chris Wilson]

It could have been done to put preload into the rear suspension on one side. This may help traction if it's been used as a drag race car with an open or none spool type LSD.

Of course, with stock struts and springs the car should sit level.... So this infers some chassis or suspension damage. an inch is a hell of a lot, I'd start doing some chassis measurements on a known flat surface. Sounds a bit ominous to me, good luck.

[Ronin 09]

ooh bugger.

from previous hoist work doesn't look like chassis.

there is no boot lining - i removed it - and no visible sign of repair...

collapsed sub frame mounts on RHS?

there have been no weird noises from the rear end, and doesn't drive funny...

[sparkmanv11]

Sounds like Sydney-Kid time!!!!!!!!!!!!!

[SteveL]

**edit** scratch that, you've already said you had to adjust one of your new coil overs to compensate.

The spacers look like they've been roughly cut from sheet and I can see longer mounting studs on the top of one of the struts.

ooh bugger.

from previous hoist work doesn't look like chassis.

there is no boot lining - i removed it - and no visible sign of repair...

collapsed sub frame mounts on RHS?

there have been no weird noises from the rear end, and doesn't drive funny...

[blind_elk]

I have since talked to the previous owner asking if it has ever had a rear shunt or damage, and he said no - he's owned it since new.

So, it's an Oz-delivered GT-R?

You will need to solve it, because loading up the RR suspension may have adverse consequences on the weight distribution across the 4 corners of the car. In that case, it will handle like the proverbial bucket of s**t.

[Ronin 09]

OK spoke to the mechanic who used to look after the car, and he said that he didn't put the spacers in.

He mentioned that the car had an alignment done by a mob who aren't there anymore (but was a long time ago), and seems to remember that they had alot of trouble doing the alignment and had to put in shims etc to get it to track straight.

Looks like I'll have to take it to centreline and get them to check it out. I'll get it on a hoist on Saturday to check it out more thoroughly

SteveL - any opinions from your brother?

blind_elk yep it is aus delivered

SK?? a little help? any suggestions?

[Sydneykid]

Firstly don't panic, it's not a big deal. I have seen plenty worse than that.

1. Springs, there is no preload difference on the springs, well none more than normal. The driver sits on the right hand side and most of his weight goes to the right rear. So there is always more load on the right rear spring.

2. That usually means that the rear drivers side has carried more weight for almost all of the cars life. So you always find the rear right on 10+ year old cars is lower than the rear left. There are little extra stresses on the strut tower mostly, sometimes the sub frame gets a set that way, the bushes wear etc etc. As SteveL suggested, the best way to find out if anything is excessively worn is to get under there and look. If the subframe bushes are badly worn enough to cause the problem they will be obviously broken.

3. Stabiliser bar, disconnect both front and rear bars (one side link will do) this will confirm whether or not the bars are bent. Unlikely but possible as they are hollow.

4. Get the wheel alignment checked by someone who knows what they are doing (not the local shonky/cheap tyre service) on a 4 wheel aligner. You are looking for set back on one side or uneven toe and camber. Chris at Centreline or Andrew at Traction Tyres are two that I would suggest.

5 If you do go to Centreline or Traction Tyres get then to put the car on the corner weight scales. That way they can even out the weights diagonally. If you do that and get the wheel alignment correct the car will handle perfectly.

Hope that helps:cheers:

[Ronin 09]

Thanks SK, will get it to them ASAP... waiting for my front coil overs to come back from Shockreco before I can do the

[SteveL]

Firstly don't panic, it's not a big deal.  I have seen plenty worse than that.

Hmmm.....sorry, but I'd be very concerned about that amount of packing on one strut on a largely road-going car. I've done some racecar and road car suspension 'tuning' (corner weighting, etc), but that amounted to 5mm at most. 25mm suggests something more serious.