Outer Limits 4x4 Board

i wish i hadn't have lifted my truck now. Put 4" coils and longer shocks and have fitted new adjstable panhard rods and home made castor plates.

i know it's been done to death, the death wobble thing. I don't get it at any speed in particular, just when you hit the right type of bump in the road the wobble goes on and everyone know what happens next.

Question is what degree castor plate adjustment should i be looking out for, i'll just go and buy the right ones. Standard tyres too at the moment, i'm too afraid to get bigger ones at the moment.

Chris

roc70y wrote:i wish i hadn't have lifted my truck now. Put 4" coils and longer shocks and have fitted new adjstable panhard rods and home made castor plates.

i know it's been done to death, the death wobble thing. I don't get it at any speed in particular, just when you hit the right type of bump in the road the wobble goes on and everyone know what happens next.

Question is what degree castor plate adjustment should i be looking out for, i'll just go and buy the right ones. Standard tyres too at the moment, i'm too afraid to get bigger ones at the moment.

Chris

4" shoud be 3deg castor correction, plates are usually to much and you normally only put bushes in for 4"

BTW the rule in 1.5deg correction for evert 1" over the 2" so you 4" is 3 deg, 6" will need 6deg correction

Also depends on the size tyres you intend to run Chris, with a taller tyre you will need less caster correction, in regards to degrees. Caster plates are not need for this size lift, bushes would be fine. The wobble you have is from the excessive caster with the plates. Easy fix, if you know what you;re doing...

the rule of 1.5 degree correction per inch or whatever is flawed, becasue it doesn't take into account the effect of the tyre's height altering the projected pivot point in front of the tyres' contact patch.

Area54 wrote:Also depends on the size tyres you intend to run Chris, with a taller tyre you will need less caster correction, in regards to degrees. Caster plates are not need for this size lift, bushes would be fine. The wobble you have is from the excessive caster with the plates. Easy fix, if you know what you;re doing...

the rule of 1.5 degree correction per inch or whatever is flawed, becasue it doesn't take into account the effect of the tyre's height altering the projected pivot point in front of the tyres' contact patch.

true, but is a good place to start

I agree with Tiny. I had bad wobbles with my 5" lift & castor plates for a long time. Now, I changed to 3 deg offset bushes and my problems are gone. I haven't changed anything else in my suspension setup.

Cheers
Joachim

JBE wrote:I agree with Tiny. I had bad wobbles with my 5" lift & castor plates for a long time. Now, I changed to 3 deg offset bushes and my problems are gone. I haven't changed anything else in my suspension setup.

Cheers
Joachim

wow someone agrees with me

As you know wheel ballance afects it a lot also, when you hav the correct castor get a wheel alignment and wheel ballance

i'll get a wheel alignment done and they will then be able to tell me if i havew too much castor.

Thanks for the replies guys.

Chris

Check the GQ bible. Bazzle had some excellent comments on lifts and alignment in the steering wobble section. If you go from plates to bushes, a toe in at around zero most likely improves steering/handling.

Cheers
Joachim

Chris don't be disheartened by the death wobbles. I've had a 4 inch lift in a couple of gq's now , one setup for about 4 years. In that time I had the wobbles a few times really bad. I have the offset bushes and have never worried about drop boxes or moving panard mounts. I've always run 35inch tyres.
My wobbles came from cheap tyres going out of round when down to about 30% , a panard bush being a bit flogged out . If your bushes are good and everything is done up nice and tight it should be good.
I took mine to Pro axle and they did a wheel alighnment on it and told me exactly what the caster and camber was doing and gave a couple of sugestions on how to get it a bit better.
4 inch is a good size for your towing too.

I lifted mine 4inch front and 5inch rear using 3.5degree castor correction bushes and running 31 tyres (at the moment). Before getting the wheel alignment the bump steer was scary. Also make sure that you have put on new radius arm to chassis bushes as they hold the front diff back and new panhard bushes as they help control the sideways travel of the front diff. (When they are badly flogged it can make the vehicle walk on the road after hitting bumps.) Also allow a thousand km or so for new suspension parts to settle. I have driven around 3000km since fitting mine and now it seems really good. (A number of ppl have commented on how well it handles.)

Another thing to do is lube the sides of your new castor correction bushes before fitting them. This helps to prevent them from snagging on the diff brackets and wearing out to quickly or worse tearing apart.

Try emailing shane at 4wdstuff
shanetamie@bigpond.com
I paid somewhere around $100 for mine

It wouldn't hurt to get underneath and check out how much slack you have in all your rods. Get someone to move the wheel left to right. The wobbles could be a combination of little things. When you lift your 4wd, problems previously unnoticed become magnified.

A decent steering damper will mask the problem or solve the problem if yours is on the way out. A Bilstein steering damper designed for the Rangie works best for the GQ and early GU's. For a GU, 2000 on I think, a Discovery Bilstein steering damper works wonders. They cost $150. You will lose an unnoticeable amount of steering lock.

Leading arm lowering brackets (Drop Brackets $250, they are bolt on and are also welded(Engineered)) should be a consideration . They correct your castor and at the same time they level out your control arms. I am no mechanic or Engineer but having your control arms on an angle must not be helping. Yes 3 degree castor correction bushes are $100 and you will need someone to press them in for you. Have you checked your control arm bushes. Maybe they are causing your prob.

In my very neglected Rangie my rods (probably all of them) have a fair bit of slack. I can feel it knocking when I change directions. I replaced my steering damper and I no longer have my frightening death wobbles. It has only masked the problem so I am going replace bushes etc. but steering dampers do make a big difference.

Let us know how you go.
Shane