[DB-101]

Further from posts in other threads here is a breakdown of what I have been through to fix, or nearly fix, the issue on my 3 patrols.

First was my 2001 DX 4.2:
Tightened wheel bearings, this helped, then replace panhard. Still had some wobble, but very minor, so replaced or re-built everything but the shocks. However, this was my first attempt at curing this issue and never thought about the shocks being an issue. Probably was the culprit.

2006 ST 6.5 Chev:
Was bought at a 3lt grenade and handed over to Brunswick for the turbo'ed 6.5 Chev. As part of the conversion a new suspension with 2in lift was done, along with this came and new adjustable drag link. Vehicle still had slight wobble at 80kph.

Fitted new bearings, no change, rebuilt swivel hub with no change. Never did the panhard before I sold it, so this was the likely culprit.

2009 Ti 3lt.
117,000km on the clock when bought. Wobbles at 80-90kph. New wheel bearings, no change, new adjustable panhard gave much improvement but still had some wobble but had increased to 100-110kph.

Fitted adjustable drag link and tie rod. Almost there, but still getting some wobble when I hit a bump, would stop with slight turn of steering wheel or when going around a corner.

As I will be doing a Duramax conversion I got a GVM upgrade, new shocks and springs all around.

Vehicle is rock solid to 135kph (ok, ok, I was going down hill with a tail wind ...)

To me the preference, and in order as most likely the issue is as follows.

1. Get a good balance, preferably on vehicle, if not then the balance machine must have a finger plate.

2. Wheel bearings, make sure they are tight.

3. Panhard Bushings.

4. Swivel Hub rebuild (remove shims first as a check, wobble goes with no shims then it needs new bearings).

5. Replace drag link / tie rod ends.

6. Shock bushings, or new shocks if had some punishment.

7. Steering box over hall.

Patrols are very susceptible to wobble, so the first order is to ensure you have a good wheel balance and make sure there is no mud or crud build up on the inside. It may be as simple as that, especially if your vehicle has done nothing hard, tires wear, when they wear the can go out of balance.

From my perspective, wheel bearings are also up there as a major. Pre-load (aka starting force) is stated as 4.3ft-lbs, some make the mistake that this is the load on the bearing as applied to the lock nut. It is not, it is the resistance of the whole hub to any rotation.

The actual bearing pre-load is 43ft-lbs as applied via the bearing lock nut tool.

Shocks.
I have a good mate, he is a landcrab man, but none the less he knows a lot on vehicles, suspension, mechanics, electronics and off road. His house looks like a landcrab wreckers yard lol.

He was saying that even with the most expensive shocks the rubber bushings take a beating off road and his opinion was that if you're a full time bush basher you are doing well to get 20,000 kms out of them (the bushings) before they need replacing.

Anyway, that's my 2 bobs worth.

 

[DB-101]

Agree on wobbles.

The other is classed as 'shimmy', as Gee mentioned.

But there are degrees of wobble, from extremely violent through to the more benign where you can keep driving, and certain repairs can, and will, reduce it as you progress through them.

The extreme is caused when something is completely flogged out.

After a good wheel balance, and if your bearings are good, then the most common fix is panhard.

 

[DB-101]

On any vehicle I have bought there are certain things I do, right off the bat.

And a wheel balance and alignment is the very first thing.

Most of all because tires are expensive and it will not take long to chew them out.

A certain person, who is a member here (though never contributes) did nothing and within 6 weeks of buying himself a second hand car needed new tires as he had scrubbed the edge off them.

Then comes:
New bearings.
Inspect steering linkage and suspension.

The above two is a prime concern, however, it is difficult sometimes to spot an issue when something is only very slightly worn. I would never have thought the shock bushings would cause anything till they were flogged out, but they made a huge difference on my current patrol.

You live and learn...

Then comes:

Change all oils.
Grease everything.
New brake pads, inspect rotors, skim if required.
Inspect coolant, brake and steering fluids, change if even slightly sus.

 

[DB-101]

Unfortunately, not in Perth at this time.

I use Mathew at Peel Tyres in Mandurah now.

He does truck and light truck stuff as well as passenger, and so has the right equipment.

So I would be looking for someone like that in your area. The chain store tyre shops should be avoided.

With the exception of Beaurepaires, you can go to one of their commercial centres in either Kewdale or Canning Vale, they do a lot of fleet, light truck, semi work in those areas.

I also used these blokes once, lost a few weights when up in the hills around Kalamunda and the vibration was really bad, was recommended to use them and they did a good job.

Drive Straight for Wheel Alignments Suspension Brakes for all Trucks Trailers Buses 4WD

They are in Welshpool, but it was some time ago.

 

[DB-101]

Yes adjusting the play in the steering box has made the biggest difference for me so far, I still get it occasionally but no-where near as bad.

Before I thought it was in my front end, but now that it is pretty much completely rebuilt and handles beautifully I can feel the vibration somewhere in the rear end, I think that while everything in the front was worn and loose the vibration just travelled there.

I think you're probably right on that, it was an issue I picked up on with the 6.5 Patrol I had. I change the front end components and drove, and still a wobble, changed back end bushings and less wobble, I put it down to the stiffening and eliminating any play that helped.

I think the whole set up is on a knife edge, it only takes one of a multitude of things on the front or back ends to get worn to tip it over the edge.