Outer Limits 4x4 Board

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Anyway got GQ shaking front end occasionally. Mostly happens on freeway at 100km/h after hitting slight deviations in road surface.
Yesterday i was towing 1.2t of rock and drove beautifully down section of freeway it normally hates at 100kph.

Could the weight on the arse end be suggesting the truck's too heavy in front (dual batt, winch, steel bar), shocks/springs are knackered, or just coincidental and is something else?

Cheers

sounds like you ahve a lifted the car with out corecting the caster. also as always with this problem check/replace your panhard bushes.
when you load the ute up it will lower your car giving you slightly more castor with will help prevent wobbles. I would doubt that shocks will affect it to much but worth checking for safty anyway but definantly check your panhard bushes.

darnoldrs wrote:when you load the ute up it will lower your car giving you slightly more castor with will help prevent wobbles. .

Lower the front maybe, but lower the rear no. By having weight in the rear the front is going to be nose up, basically the same as raising the front suspension. This is going to reduce positive caster.

If you already have caster correction fitted, then definitely check your panhard bushes first. Also make sure the bolts/nuts holding the panhards are done up really tight. If you have poly bushes, fit genuine Nissan rubbers ones as the polyurethane elongates in the hole with wear and makes them loose and sloppy, it doesn't take much. If that's all ok I would be having a good look at swivel bearings. Good luck!

depends on how much of that 1.2t is infront of the rear diff. I would be assuming that it is leaf rear with that weight so the front will drop a little, one again, assuming lots of things I guess.

Don't have any solutions for you but I'll be interested to see what the suggestions are as I notice with my GU the highway shakes go away when I have the camper on the back.

It's a GQ wagon with coils all round, 5" lift. Trailer had crushed rock so evenly distributed load. As truck is lifted the trailer sits on a bit of angle and if anything would be pulling rear down and therefore, front up. Panhards are genuine bushes, ok nic and tight.

I had suspected that king pin bearings may need replacing but thought this phenomena of the trailer might have cast some light on the issue. Looks like i'll be putting a hub kit through it and see how that goes.

Oh yeah, has offset bushes for castor correction. Maybe they're shagged. Thinking about dropboxes?? Expensive little suckers though, and then the cost of genuine bushes. Do they get hung-up much?

Draglink (front rod) bush is fuked. Most ppl tell me that will not cause shaking. What's the outers braintrust's thoughts??

Thanks guys

at a 5 inch lift, castor corection bushes will not be giving you enough castor for starters.
I thought you had a a ute and the rock in that. cant think of why with a trailer on would make it better.
if your drag link it worn i would expect this could cause an issue but not totaly certian there. How is your steering dampner??
I have decided to go for drop boxes but havnt got them yet so i cant say about getting hung up, however if they do then you wont get the chassis over what ever it is anyway.

darnoldrs wrote:if your drag link it worn i would expect this could cause an issue .

spot on mate

Also check your steering box for play.

I have been trying to get hung up on my drop boxes to see what my limits are but it hasn't happened yet, think I will have to try harder!

already been said, but castor bushes on 5inch really doesn't cut it.

if it's an early GQ some of them had a nasty habit of cracking the mount for the panhard rod to chassis. But it would have a pretty vague steering feel.

because it's at a certain speed, that nearly always means castor.
trailer affects it because it would raise the front slightly meaning that you would need a different speed to set the death wobbles off. Dare I say faster than 110kmph.

Drop boxes are the cheapest way out with best results. Otherwise look at dropped radius arms.

Death Wobbles for president!