Outer Limits 4x4 Board

Has anyone had any luck dialling out the dreaded 80kph Patrol shimmy with an adjustable steering damper? I noticed that Tough Dog make one now but am concerned that if I put too much damper on it, then the steering wheel won't return to centre after cornering.

Which brings me to my question . . . . does anyone know of an RTC steering damper for Patrols that also includes a damper adjustment?

BTW - I have done all of the usual things to dial out the shimmy from shims on the kingpins, panhard rod bushes, wheel balances, tightening the wheelnuts in the right order, etc. The issue is obviously the inch of offset on the wheels I have for my muddies.

Check your Radius arm bushes at both the diff end and the chassis, and for f*cks sake don't get a RTC damper, it will not fix your problem.

Borrow someones tyres. You can borrow my tyres while I use your muddies.

Also are you sure you tightened those wheel nuts in the right order because they change sequence since they brought out the manual.

Shane

If you removed some shims and that didnt work id go for some new swivel barings, if not im not too convinced that a dampner will fix it , it might help a little but the problem will still be there.

RTC steering dampners are evil crap.

Get yourself a Procomp steering damper.

i got one of the adjustable dampeners in mine and it seemed to fix it.. steers perfect.. it is a little heavier in the steering but nothing major

can i ask why RTC dampers are crap?

For the cheaper RTC steering dampers you get a small steering damper which is too small for a Patrol. You can get a big bore RTC steering damper for over $300. I don't know how these things go yet.

When you are driving straight there isn't much load on the spring so it doesn't help much.

The extra load caused by the spring has been known to stuff up your power steering.

Some think they are great, some think they are crap.

When I sell Procomp or EFS Extreme or Ironman steering dampers I get no complaints.

There are other threads here on the same subject.

Shane

Dampeners shouldn't be used to fix stuffed steering. You should be able to street a patrol without a steering dampener.
So its more trail and error to find the fault. Panhard rod, Radius arm bushes, Kingpin bearings, wheel bearings. Buggered tie rod maybe. Out of balance tyres.

turps wrote:Dampeners shouldn't be used to fix stuffed steering. You should be able to street a patrol without a steering dampener.
So its more trail and error to find the fault. Panhard rod, Radius arm bushes, Kingpin bearings, wheel bearings. Buggered tie rod maybe. Out of balance tyres.

Steering isn't stuffed. It is fine with the factory wheels, just the offset muddies cause the shimmy despite being balanced multiple times. As for streeting a patrol with the damper, I'd hate to be in that position. I stuffed one on my old MK and even with 31-inch road tyres it was a nightmare at anything above 40kph. Installed a cheapie Pedders damper and it was good as gold. Just my experience.

The other suggestions are all likely suspects, but as I originally stated they are in good working order. It just seems to be an inherent problem with patrols and I was wondering if anyone has had success with RTC adjustable dampers.

It is pretty common for muddies to go out of round. I have had probs with brand new muds on an 80 Series so your Nissan may no be to blame this time.

Shane

Offset rims or wider rims (like 10" rims) will increase the 'scrub radius' which invariable will create a shimmy or wheel wobble.

RTC Steering dampeners will usually only amplify the problem by 'loading' the spring on each oscillation of the shimmy.

There are many factors with a GQ/U that cause or increase tha chances of a shimmy occuring - most of which are discussed elsewhere on OL. Tyres and the offset of the wheels are a major cause. Panhard rod bushes (only use genuine Nissan) are a common cause. Only use a good steering dampener - such as those Shane has mentioned. RAW also have good steering dampener.

Peter K.

Are we talking about driving along at 80-100km/h fine, then hit a sharp bump causing the steering to shake violently?

I have had this problem twice with my 4" lifted gq running cruiser off-set rims.

First time was worn tie-rod ends. cured that a couple of years ago.
Got it back again the other weekend. Cant find anything worn in the steering but I had just turned all 4 tyres to the inside due to tyrewall wear.
So took those MT's off and put my simex on and went for another drive.
With the simex it would not play up.
I think the odd tyre wear caused by swaping the tyres inside out has caused the problem this time.

Just my thoughts
Chris.

PS. there may still be an underlying problem with my car. But seems ok at this stage with my 2nd set of tyres fitted.

i have a big bore tough dog rtc on my patrol and find it great, steering used to be very touchy and shimmer occasionly, its fine now.

if you have 35's on, that will be your problem. most patrols seem to work fine with 35's but some just hate it. i would suggest maybe leavin your muddies just for play and gettin some road tyres for daily driving.

turps wrote:Dampeners shouldn't be used to fix stuffed steering. You should be able to street a patrol without a steering dampener.
So its more trail and error to find the fault. Panhard rod, Radius arm bushes, Kingpin bearings, wheel bearings. Buggered tie rod maybe. Out of balance tyres.

x2

You'll probably find that the bigger diametre and weight of the muddies is causing the problem to rear its head. Go through ALL of the usual bush/bearing/linkages and you'll have it sorted.

Coxy

Large tyres and offset rims just amplify the problem. So do over inflated tyres and worn tyres as they have less contact on the road and turn easier/faster allowing the harmonic oscillation to occur with less worn components. The only real fix is to tighten everything up (bushes, bearings, tie rod ends etc) and correct caster. If that is right, you will only need a standard damper. I ran 7 inches of lift with 37's and had no problems once I replaced all of the worn bushes etc. I couldn't even get it to wobble a little bit no matter how hard I tried. Before I fixed all of my problems I tried both a small and large return to centre damper and neither did as good a job as the regular damper that is on it now.

Swivell hubs, wheel bearings, tie rod ends and upper shackle bushes (MK) fixed it for me. I had 37's on 15x8 -23mm offset rims, and genuine Nissan damper. It got the shimmies on skinny H/T tyres, 31" AT's, and on the 37's (not as bad though). Plus, the car was sooo much better to drive doing all of that stuff.

Coxy

Thanks for the replies. I guess I'll go back and double check all of the potential problem areas. Either that or sell the muddies. :-(

I've got 35's which are pretty worn (5mm left) and 6" coils but no death wobbles or shimmy anymore.

It was a combination of incorrect swivel bearing (shimming) and wheel bearing preload and a worn out std stg dampener.

I went to the very upper end of the scales when setting the preloads because of the 35's and the rim offset.

Before this I ditched the castor plates and std arms and fitted new Nissan bushes to Big O drop arms but it still got the "death" wobbles. Once I checked and set the preloads its been good. Repacked the bearings while I was at it too.

After this it had a bit of shimmy over bad bumps but a new Dobinsons dampener fixed that.

cheers