Wiggling Rear End

[R.3.2.G.T.R]

hi peeps,

need some help sorting out my rear end on my 32R, can feel rear wiggling from side to side at around 60-70kms, on smooth road, no tramlining etc, worse in the wet

few things done recently:

all hicas bits removed completely and fitted with driftwork elimination kit

wheel alignment done at jax blacktown - rear toe at 0mm both sides

now before the hicas mods, this wasnt an issue, was running approx same camber at rear, not sure on toe

i have subframe collars and not installed yet, could existing ones cause the issue? anything else i should be checking in the meantime

tonight i will be double checking the wheel shake and coilovers (tein current set to middle of range) and all bolts in the vicinity

tyres are month old, same all round and had wheel balanced when fitted, car is legal height and street driven

anything wrong on my alignment sheet?

[Sinista32]

I'll check mine when I get home. I don't see anything jumping off the page.

Sounds silly but have you double checked wheel nuts ?

- track difference and thrust angle stick in my mind for some reason but will check

Camber is the exact same front and rear ???

Did you ask for 0 toe ?

Edited May 23, 2013 by Sinista32

[R.3.2.G.T.R]

I'll check mine when I get home. I don't see anything jumping off the page.

Sounds silly but have you double checked wheel nuts ?

- track difference and thrust angle stick in my mind for some reason but will check

Camber is the exact same front and rear ???

Did you ask for 0 toe ?

wheels nuts torqued

camber front and rear is identical but i didnt ask for that, running 18x10+15 rims so cambered as little as i could for it to lineup with the guards

rear toe i asked for 0mm thinking it was better and didnt want it to contribute further to already cambered rear tyre wear

[gtr jet]

I had a similar issue and fitting rear sub frame collars fixed it for me.

[darksky34]

could be any number of things, but i think i had similar with my car (with known issues), before i put in:

• hicas lock bar
• new tie rods (rear)
• new shocks (had a leak in one)
• sway bars
• pineapples (subframe alignment kit???)

before all that, car would sometimes feel like it wobbled on a turn, or over a small bump. now all gone.

[GTSBoy]

The quick and dirty test/check is to get the rear toe set to -1mm and see if that makes it feel better. With 0 toe your wheels actually end up toed out while driving because the dynamic forces transmitted from the road push the wheel backward relative to the car and that causes it to swing around the upper and lower inner suspenion mounts - basically twisting the bushes. The upper tension arms only do a certain amount to prevent that because they are on an angle themselves. Toe out causes the wanders, so dialling it out is an easy check.

Other than that I would say you need to look for;

*Sloppy tie rod ends from the HICAS, assuming that you still have them there (and most HICAS eliminators do leave them there).

*Sloppy bushes in any and all of the suspension arms.

*Tired subframe bushes. Collars will help, but brand new ones are a serious improvement. It's a lot of work to change them, but worth it.

[R.3.2.G.T.R]

thanks for the replies guys

no tie rod ends left and will check all arms tonights, coilover isnt leaking

otherwise ill slap on the c-collars over the weekend and have it adjusted to -1mm on each side as suggested

i have whiteline rear swaybar installed with new link bushes etc, that was done a while back

will report back tonight after checking

[Sinista32]

As said by GTSboy - Start with adding rear toe.

I'm on the street most of the time and handles very well. Dialled in to handle well for the street and reduce tyre wear (so a compromise)

At least for mine, so you can compare. (and I trust my guy)

Toe on the front - Half toe +1.5 degree (total +3)

Toe on the rear +2 degree's - Will straighten up when driving. Plus I really don't like tracking.

I also run more caster on the left than the right (opposite to yours)

Neg camber on the front -2 (slightly more on left than right)

Neg camber on the rear -1.5 (slightly more on left than right)

Track difference of 0.07

RIms - 18x9.5 +12

Mine is also different on the king pin angle and thrust angle.

Adjusted so it doesn't dart to one side under Hard acceleration.

Edit: think they added more camber to the rear (+2) last time but I didn't get a printout

Edited May 23, 2013 by Sinista32

[Duncan]

Your alignment is fine, might be a little taily on the track but that can be fun (personal preference). Plus, alignment would only create instability at the rear if there was a lot of toe out.

So, I reckon there is a problem in the toe control. Start at the centre and make sure the lock bar is bolted down securely, then check the inner tie rod ends are tight. But I reckon it's almost certainly stuffed ball joints at the outer/hub end of the tie rods. That was the issue I had, and I had exactly the same "tail wagging" feeling. Unfortunately they are both painful and expensive to replace, I could not find an aftermarket option

[R.3.2.G.T.R]

Your alignment is fine, might be a little taily on the track but that can be fun (personal preference). Plus, alignment would only create instability at the rear if there was a lot of toe out.

So, I reckon there is a problem in the toe control. Start at the centre and make sure the lock bar is bolted down securely, then check the inner tie rod ends are tight. But I reckon it's almost certainly stuffed ball joints at the outer/hub end of the tie rods. That was the issue I had, and I had exactly the same "tail wagging" feeling. Unfortunately they are both painful and expensive to replace, I could not find an aftermarket option

thanks Duncan, I believe u have nailed down the issue, re-checked all bolts and tried to see if any bushes are worn and leaky without much luck

What I did find is that one of the elimination kit brackets is not bolted "square on" like the other side, although not loose might under load be moving from not being aligned squarely

I'll fit the subframe collars and set n torque the bracket correctly on the wknd before alignment with specs listed earlier

One thing I don't get as kit came without instructions is, other than the bracket bolt being done very tightly, what will stop the bracket from tilting from load, better pic of one side below

[Duncan]

ahh interesting, I hadn't seen that style of lock kit before. It's very similar in concept to the factory non-hicas setup on the stagea.

I am not excited about the design of the brackets because they have a single bolt, and no apparent locating dowel or flanges against a locked surface. In any case, if a bracket with a bolt that big is moving it will not be a smooth "wiggle" but rather a sharp/clunk unless it is finger loose. also you would see scraping on the paint of the subframe if it was moving.

given the inner and outer rod ends are bearings and new they should be easy to check for slack. is the outer end now a bush of some sort instead of the factory ball joint? If so, it might be the whole subframe that is shifting relative to the car?

[R.3.2.G.T.R]

yeah i couldnt find any info on how the bracket is located other than the single bolt and looking at other ppl's install pics, it appears to be the same

no paint or wear marks on the bracket and its still relatively tight

the outer end is now bush replacing the factory ball joint, i also checked both wheels for any movement but it was solid, its odd that only now the subframe is shifting or perhaps it was happening previoulsy but not felt due to worn ball joints

is lowering subframe just a matter of raising the car to a suitable height with the wheels sitting on something and undoing the bolts in front and back till the end of the thread?

[Duncan]

I guess that could work....but I've always put the car up on stands and then put a jack under the centre off the diff (good balance required). Nuts off, or right down to the bottom of the thread, and then lower it on the jack

[luke gtr]

Your alignment is fine, might be a little taily on the track but that can be fun (personal preference). Plus, alignment would only create instability at the rear if there was a lot of toe out.

So, I reckon there is a problem in the toe control. Start at the centre and make sure the lock bar is bolted down securely, then check the inner tie rod ends are tight. But I reckon it's almost certainly stuffed ball joints at the outer/hub end of the tie rods. That was the issue I had, and I had exactly the same "tail wagging" feeling. Unfortunately they are both painful and expensive to replace, I could not find an aftermarket option

werent as bad as I thought they be, price or difficulty to replace.

[R.3.2.G.T.R]

alright, c-collars installed and every bolt that i could get to tightened up with torque wrench, will try and squeeze in an alignment tmrw lunch-time, hopefully last one for a while and it fixes the wiggle

[R.3.2.G.T.R]

As said by GTSboy - Start with adding rear toe.

I'm on the street most of the time and handles very well. Dialled in to handle well for the street and reduce tyre wear (so a compromise)

At least for mine, so you can compare. (and I trust my guy)

Toe on the front - Half toe +1.5 degree (total +3)

Toe on the rear +2 degree's - Will straighten up when driving. Plus I really don't like tracking.

I also run more caster on the left than the right (opposite to yours)

Neg camber on the front -2 (slightly more on left than right)

Neg camber on the rear -1.5 (slightly more on left than right)

Track difference of 0.07

RIms - 18x9.5 +12

Mine is also different on the king pin angle and thrust angle.

Adjusted so it doesn't dart to one side under Hard acceleration.

Edit: think they added more camber to the rear (+2) last time but I didn't get a printout

was that 2deg rear on each side or total?

[Sinista32]

Each side. Works for me

Neg camber on the rear -1.5

Toe +2

Edit:

Although as some one above said you shouldn't have an issue with the settings you originally posted.

Your camber settings will save just a little additional wear on the tyre inside. Which is normally fine for normal street driving.

More camber on the front for turning and less on the back as it will follow and does not "turn".

I would only suggest you reverse your caster settings up front as it will help stop drifting towards the gutter.

General rule is as much caster as you can get without scrubbing and more on the left than right.

Edited May 28, 2013 by Sinista32

[Sinista32]

Have you identified and rectified the issue causing the Wiggling rear end ?

[R.3.2.G.T.R]

yeah got an alignment over the wknd, rear feels heaps more stable

i re-adjusted the brackets to be more square and torqued it, something i didnt do initially

also the rear diff bracket/support bar was a lil loose on one side, ended up checking all bolts that i could get to

there was one stretch of road which previously amplified the wiggle, much much better on that stretch now