Outer Limits 4x4 Board

I got this real bad shake in my mk patrol, i tighten the wheel bearings got a bit better, then top shackle bushes little bit better again. But it still shakes around 40 to 70 when i hit a small or big bump, went out today got to 80 to 100 shake stops or pulls out of the shake but the shake is very minimal at that speed. Any ideas

steering dampner?

tyres balanced? (buckled rims, out of round tyre etc)

had 3 sets of wheel on that's not the prob steering dampner still good in fact like brand new, king pins still in great shape.

had an old MQ that had the same prob no matter what I tried, did the death woble thing about 40kph-70kph then one day found that one of the springs was slightly bent near one of the eye's !!!!!!
not saying thats what wrong with yours though

Here is my list off the top of my head (in no particular order) of things which can cause this on MQs and other trucks

1) Worn knuckle flange swivel bearings or incorrectly adjusted bearings
2) Wheels out of balance
3) Steering damper shot
4) Worn shock or shocks
5) Track rod ball joints worn
6) Relay rod ball joints worn
6) Steering relay lever bushes worn
7) Pins and/or bushes in spring shackles worn
8) Worn or incorrectly adjusted wheel bearings
9) Loose wheel nuts
10) Loose spring U-bolt nuts
11) Cracked spring mounts

In my experience no 7 above is a common culprit especially with the MQ which had steel bushes and steel pins. Often though it is just a gradual cumulative wear of all the joints in the system - steering rods and springs. Fixing one thing helps but only for a short time. I have had these wobbles several times on my MQ - twice the only permanent fix was a replacement of all the slightly worn ball joints, and at other times it has been the shackle pins.

Replacing the steering damper merely masks the underlying problem temporarily - the first MQs did not even have a damper or provison for one and ran just fine (for a while). I have replaced the Nissan drag link, which had integral ball joints and was expensive, with a tube threaded to take Landrover Series II or L/R Discovery ball joints which are a lot cheaper and quicker to replace. I have also found it helpful to fit a length of motorcycle inner tube over the spring shackles to keep the water and dirt out and the grease in - seems to be quite effective.

For a while I ran my truck with the sway bar disconnected but have put it back both for on and off-road work. I found that without it the springs twisted excessively causing accelerated wear in the spring shackle bushes and I also broke the front spring U bolt (the square one) no less than 3 times. Have had no futher breakages since I reconnected the bar.

Cheers, David.