Outer Limits 4x4 Board

Ok here goes...
First off i tried the search option and it either went to a page that was no longer there or it didnt really answer my question.

About the car...
SWB GQ, 6" coils, 5degree caster plates and Haultech Slotted bushes

I just installed some Haultech slotted bushes into the front of my GQ shorty. Before i put them in i had a little bit of steering wheel shake, but it was nothing really. After putting them in the 'shake' was undrivable.
It voilently wobbles from side to side, as soon as i hit 60kms. I have to stop the car to stop the wobble.

So far ive replaced the rotors, pads and overhauled the calipers (only cos it needed doing anyway). Packed the hub with new bearings and seals. Next im doing the panhard bushes and getting a wheel balance and alignment.
I have an adjustable draglink on its way also

WHAT ELSE CAN I CHECK???

Ill be replacing the tierod ends also.

Can the shims under the swivel hub cap/bearings cause any problems?

Please help ASAP!

Cheers

Definately do the panhard rod bushes!

I have had the same steeing wobble issues but mine kicked in at 95Kmh. Then had to slow to a stop to get them to stop.

Through trial and error I believe that we have found what can cause this. It seems to be that it is caused by bump steer from the lugs on the tyres. This creates movement in the tie rod and panhard rod and translates to up and down movement of one of the front wheels.

I replaced all the suspension components on the front end and still it happened. When I changed the panhard rod over then it stopped. I have also increased the pre-load on the king ping bearings by removing one of the shims top and botoom on both sides. This has cleared up the issue. I have not replaced the tie-rod yet.

Hope this helps.
Thwack

When I had my GQ Patrol lifted 5 inches, I had the same issues.

I went about changing panhard bushes etc and nothing fixed the problem. It wasn't till I dropped it back down to a somewhat standard height to sell, that the wobbles appeared to have deminished.

My next point of call was going to be the preload on the swivel hubs. I think this is the main issue. Well, for me it was anyway........

Hope this helps.

Keep us posted whether or not this fixes your problem.

Regards

Anthony.

did u put the tyres back on the same side they came off from? and to every patroller that has front end shimmy, please start diagnostics with a good wheel balance. there could be more wrong with ur truck but all it takes is for the wheels to be slighty outta whack balance wise and our beloved patrols behave like stage coaches.

also sthings like swivel hub preloads etc etc will not be effected by changing bushes only. if it drove good before the slotted bushes it should not change after unless u changed something putting it all back together. make sure all ur bolts are tight on ur castor plates. actually piss them off altogether and get some custom arms or drob boxes....

better still get an on car balaance

your caster could be out, it doesn't mater if someone says for a six inch lift you will need 5 degree caster plates or what eva
every patrol is different on my shorty they had to stuff around with different caster plates to get the caster as close as possible

thwack wrote:Definately do the panhard rod bushes!

I have had the same steeing wobble issues but mine kicked in at 95Kmh. Then had to slow to a stop to get them to stop.

Through trial and error I believe that we have found what can cause this. It seems to be that it is caused by bump steer from the lugs on the tyres. This creates movement in the tie rod and panhard rod and translates to up and down movement of one of the front wheels.

I replaced all the suspension components on the front end and still it happened. When I changed the panhard rod over then it stopped. I have also increased the pre-load on the king ping bearings by removing one of the shims top and botoom on both sides. This has cleared up the issue. I have not replaced the tie-rod yet.

Hope this helps.
Thwack

Thanks everyone for the help.

I had the 35s balanced today by Kmart tire n auto but its still sh%thouse. I took the panhard off tonight and im gunna get new bushes pushed into it on thurs. When i took the pan off the bushes looked ok to the eye, but all should be revealed tomorrow.

I have also been told that a 5 degree caster plates for 6" coils is NOT right. Im jus going on what im told, i hope they are 5 degree plates...
So after replacing the pan bushes, ill take it for a spin. If it is still crap im gunna drop in some 4" coils and see if it fixes the problem. If it does well my caster plates might be the wrong ones.

Cheers Justin

viperguy wrote:did u put the tyres back on the same side they came off from? and to every patroller that has front end shimmy, please start diagnostics with a good wheel balance. there could be more wrong with ur truck but all it takes is for the wheels to be slighty outta whack balance wise and our beloved patrols behave like stage coaches.

also sthings like swivel hub preloads etc etc will not be effected by changing bushes only. if it drove good before the slotted bushes it should not change after unless u changed something putting it all back together. make sure all ur bolts are tight on ur castor plates. actually piss them off altogether and get some custom arms or drob boxes....

It had a little wobble in the steering wheel previously, and now that ive given it more movement in the radius arm it may be emphasizing the problem that wasnt that noticable before. Im not blaming the bushes for the wobble at all. I can wait to get this sorted and get it into th bush!

Cheers

thwack wrote:Definately do the panhard rod bushes!

I have had the same steeing wobble issues but mine kicked in at 95Kmh. Then had to slow to a stop to get them to stop.

Through trial and error I believe that we have found what can cause this. It seems to be that it is caused by bump steer from the lugs on the tyres. This creates movement in the tie rod and panhard rod and translates to up and down movement of one of the front wheels.

I replaced all the suspension components on the front end and still it happened. When I changed the panhard rod over then it stopped. I have also increased the pre-load on the king ping bearings by removing one of the shims top and botoom on both sides. This has cleared up the issue. I have not replaced the tie-rod yet.

Hope this helps.
Thwack

So u have 1 shim in the bottom and 2 in the top, that correct??

Thanks Justin

dieseldude wrote:When I had my GQ Patrol lifted 5 inches, I had the same issues.

I went about changing panhard bushes etc and nothing fixed the problem. It wasn't till I dropped it back down to a somewhat standard height to sell, that the wobbles appeared to have deminished.

My next point of call was going to be the preload on the swivel hubs. I think this is the main issue. Well, for me it was anyway........

Hope this helps.

Keep us posted whether or not this fixes your problem.

Regards

Anthony.

Yeah all the replys have helped, thanks everyone!!!

Im gunna remove the 6" and replace them with 4" coils and see what happens. If no change ill put the 6" back in and then ill play around with the shims


Thanks, Justin

Bartso wrote:your caster could be out, it doesn't mater if someone says for a six inch lift you will need 5 degree caster plates or what eva
every patrol is different on my shorty they had to stuff around with different caster plates to get the caster as close as possible

Can someone please confirm the distance between the upper n lower hole in a 5 degree caster plate? I measured it and i got 61mm centre 2 centre. Is this right for 5 degree??


Bartos,
You had 6" coils in ur shorty, what degree plates did u use??
Did u remove any shims from urs?

Thanks Justin

Changed the panhard bushes today and tightened all the radius arm bolts.

Still no change.

I actuall ordered a set of 4" coils and drop boxes from superior today. Im over the 6" lift.

In the meantime im gunna fit an adjustable draglink and downsize tires to see how it goes then...



Justin

Sounds like you have done everything you can..
Bit of a long shot but check for a chassie crack between panard mount and the steering box. Its a long shot cause I was flat out getting over 40kmh when mine went with the panard mount flapping around

justinshere wrote:

Bartso wrote:your caster could be out, it doesn't mater if someone says for a six inch lift you will need 5 degree caster plates or what eva
every patrol is different on my shorty they had to stuff around with different caster plates to get the caster as close as possible

Can someone please confirm the distance between the upper n lower hole in a 5 degree caster plate? I measured it and i got 61mm centre 2 centre. Is this right for 5 degree??


Bartos,
You had 6" coils in ur shorty, what degree plates did u use??
Did u remove any shims from urs?

Thanks Justin

mate not sure what caster plates your spose to have but i have a 5 link in the front of mine so its adjustable

ok, i ditched the 6" coils in the front and put in some 4" and rotated tires.
Still got the damn wobble.
Im waiting on some drop boxes and adjustable draglink from superior.

Hope it works this time.

Next... replace tierod ends and then do the swivel hub bearings.

6inch coils is too high for a shorty mate u have way too many thing to correct to get it to drive properly, when u put your drob boxes in with the 4 inch coils it should drive like a standed hight one changing the tie rod ends and swivel hub bearing wont fix any thing unless they are worn out, should get them checked by a steering joint before forking out the dollers. a swivel hub it is about $200 and take about 4 - 6 hours to clean and fit correctly. u can check them your self by jacking it off the ground disconecting the steering arm and draglink off the swivel housing and turn the wheel by hand it should turn smoothly, if it feels really nochy then get them checked out ...

should get a W/A done first to see how much caster it has after the lift then u know how much to change it, to get it right

just sounds like a caster problem to me.


any other problems jus pm me

CHEERS SKIPPY

just went through the same problem with a gu patrol . changed all the bushes and was still there sure it was gonna be castor too . but by the off chance i was told about the kingpin bearing so i checked the swivel hubs and they were quite loose . removed a few shims til it moved nicely ( firm ) and the problem is now gone . have had a gq with 6 inch coils and mate has one with 4 inch never had any problems just luck i guess . also left front wheel bearing is pretty well known for coming loose on them .

see the other post (difference between tie rod end and rose joint)
i answered it there
Its all about tyre pressure if everything else is sorted. I have had the same problem and fixed it.

didnt realise u were on the central coast.. if u wanna meet up some time u can check out my set up and take it for a spin. 5inch coils 2inch b/l, 37 mtrs and no wobbles... i started a week holiday today so wont be back on the coast for a week but next weekend will be cool..

If it happens every time you hit 60km/hr than it won't be the steering damper, it is worth pulling it off and checking though..

Castor
It is very important for a shorty that the uni joints are parallel to each other. If they are not parallel then you get vibes. If so there will be more centrifical force coming off the rear uni then the front so it goes out of phase. They are designed to cancel each other out.
Many use gearbox spacers to stop the severity of the angle as anything over a 10mm lift on a shorty will cause probs. You may have got it pretty right before but your uni's are going to wear so much quicker so this could be a prob but leave it till you try other stuff that isn't so expensive.

Try pulling your front driveshaft off and go for a drive. You can at least isolate the prob to the front.

After this pull your tailshaft off and drive on the front.

Another prob is maybe the holey bushes are a bit too holey, maybe you damaged them putting them in. Also maybe the softer bushes have changed the castor angle a bit.

If it still no worky there is another thing you can try but only as a last resort.
You could use a double cardin joint out of a Hilux and get a shop to put it onto your shaft. If you do this you have to have the other standard unit just about straight up the shaft but not exactly. If you do this you than have to cut and straighten your coil holder and shocks holder on your axel.

If it still doesn't work buy a LWB like you should have in the 1st place.


Shane

Update! with a happy ending!!


Took out the 40mm wheel spacers.... No change.

Rotated the tires without the spacers in.... No change.

Checked out the shims, in one side, 2 in the top 1 in the bottom. Other side 1 in top, 1 in bottom.
So i adjusted them so the hubs didnt move as freely as they did, they were pretty loose.... No change.

Got the S&%TS!

Pulled the front end apart and installed Superiors Drop boxes with new rubbers on the chassis end of the radius arm. And took out the caster plates off.

Took it for a spin and it was great! No more wobble!

Thanks everyone who helped along the way.

Cheers Justin

Mines got castor plates on the standard radius arms and a 6" spring lift but there's no wobbles or shakes even at 110. I think it's because it's all so tight with the angle of the arms at the chassis end lol!
It's all getting fixed though with proper drop arms etc. and pissing those castor plates off.
cheers, sudso

i have EXACTLY the same problem.....with exactly the same gear (axcept i have snake racing bushes in the arms)...

so far i have only done a wheel balance to no avail.....

reading everything on here i dont know where to start. im not confident enough in myself to do the swivel hubs and it would probably cost alot for someone to do it.....and i wont know whether it will fix it...

what sort of order (from simplest and cheapest) would i sort this problem out with.

cheers
PAUL

vanbox wrote:i have EXACTLY the same problem.....with exactly the same gear (axcept i have snake racing bushes in the arms)...

so far i have only done a wheel balance to no avail.....

reading everything on here i dont know where to start. im not confident enough in myself to do the swivel hubs and it would probably cost alot for someone to do it.....and i wont know whether it will fix it...

what sort of order (from simplest and cheapest) would i sort this problem out with.

cheers
PAUL

Hey Paul,

Thats the problem i had not knowing where to start.

First thing id replace is the panhard bushes, get genuine ones from nissan, they are less than $20 each.

Now 6" lift with 2" body im guessing?
Is it running on caster plates or drop arms?
If u say plates that could be a problem, thats what i put mine down to. Maybe it was either the caster plates themselves were sh*thouse or the caster may have been wrong. But saying that i had 6" coils with 5 degrees caster then dropped it to 4" coils still with 5 degrees caster and there was no change in the wobble.

I didnt end up rebuilding my swivel hubs i jus took out the shims, i know ill have to rebuild it soon though.

See how u go with the panhard n keep us up to speed.

Cheers Justin

I'm running a 7" lift in a shorty with 37 MTR's and have no wobble at all, at any speed. However, at one stage mine was so bad I ran off the road at 80km/hr after hitting a small bump. Very scary stuff. Obviously the bigger you go the harder it is to control the steering but it is possible. I've proven that. I have tried to hit portholes at 60, 70, 80, 90 km/hr and can not get even the slightest wobble happening anymore.

So how do you get rid of it? A lot of the things that effect it have been mentioned so far but it is the combination of a lot of things that usually mess things up. Firstly it is a harmonic imbalance, so it usually happens at similar speeds and any movement in you steering geometry can allow it to happen. i.e. it can be any of or a combination of the following: Loose swivel hubs, unbalanced tyres, worn panhard bushes or loose panhard bolts (polyurethane bushes wear much faster that rubber!), worn tie rod ends, poor steering damper (especially return to centre dampers!! I have a small and a large one sitting in my garage for anyone with a Toyota to buy), worn radius arm bushes (usually overlooked), standard radius arms with big spring lifts, offset rims, 35's on 8" rims, tyre pressures, and a loose steering box.

All of these things allow small movements and when a big tyre hits a bump and flexes it creates a wave of energy. If there's enough movement in the steering it creates a harmonic resonance which builds until the death wobbles (same thing happens on bikes). When this happens it obviously puts more strain on everything which wares everything faster, which makes the problem worse.

I chased this problem for a long time and had swivel hubs, tie rods already done (amongst other things I had tried that didn't help much like the tuffdog RTC dampers etc) when I had the above mentioned incident. I bit the bullet and swapped my 8" offset rims for 10" rims (wider rims give a flatter pattern on the road providing more friction) much improved but not enough. I then replaced my standard radius arms and caster plates with snake arms and put a heavy duty truck steering damper (cost $100 compared to $350 for tuffdog!) and had the tyres balanced on the car (at prosteer in Wollongong) and everything has been perfect since.

Since I run 37's I get a balance every 6000k's (every time you go 4B'ing and let air out and pump back up it throws the balance out a bit) and adjust wheel-bearings every 12000k's to keep it all tight. I also run my tyres on the road at 40PSI as it allows the walls of the tyres less flex, therefore less wobble to start.

Hope all this answers some questions.

HEY 4WD STUFF
Why would it be the REAR tailshaft if it wobbles thru the steering wheel????

From my experience rear tailshaft imbalance you feel through your seat and you hear a hum. If its the steering wheel wobbling, its the front end. i.e. steering components or tyres.

I agree 100% with Nelso. It is usually a number of things that create the problem and it IS harmonic. The first thing that we usually look for is castor, cracks in the chassis around the panhard mount (early model GQs), panhard rod bushes, tie rod ends, wear in the pivot bearings, wheel bearing adjustment, tyre condition and pressure etc.

RTC steering dampeners never fix the problem and sometimes make it worse as they can amplify the harmonic vibration.

Some vehicles check out OK and the problem still persists. We then have to look at the more expensive options. By more expensive options I mean aftermarket control arms or drop boxes. We offer these as recommended alternatives on any of our bigger lifts as you can usually eliminate the death wobbles before they start.

The pressure created on the control arm bush (chassis end) is what is eliminated by either aftermarket control arms or drop boxes. Yes - they correct castor also - but we have changed patrols with correct castor to aftermarket arms (castor has remained unchanged once correction plates have been removed) and eliminated the wobble. The bump in the road that upsets the suspension has the spring and the pressure on the bushes working against each other and this is what sets up the harmonic vibration.

Tyres etc. etc all play a part also - but get rid of the pressure on the bush and you are on a pretty safe bet - plus you will increase downward travel & ground pressure (providing shocks & link pins don't hold the wheel up)

Peter K.

Do drop boxes (whatever they are) effect the clearance??
Also what are the costings of the drop boxes and aftermarket control arms to suit my lift???

Drop Boxes do affect clearance - so although very good for the on-road handling are not so good for the off-road performance. The best Drop Boxes I've seen are from Mick at Superior Engineering at $385 per pair plus postage.

Radius arms by 2-D-Extreme are available for various height lifts and are longer that the original arms to move the axle forward again. They correct castor and eliminate the pressure on the chassis bush. They are priced at $1075 per pair plus freight with new rubber bushes pressed into the diff end. They do NOT allow for the front swaybar to be reconnected.

These are better for the off-road as they are stronger than the original arm and do not reduce clearance. They are not as good on-road because you have no front swaybar and because the arm is still on an angle from the chassis to the diff and not 'close to horizontal' as designed by Mr. Nissan.

Using drop boxes instead will return this angle back to original - or close to it.

A quick chat about suspension dynamics - if we look at (for example) tightening a wheel nut. We place the socket on the nut and a breaker bar out horizontally. You place your palm on the end of the breaker bar and push horizontally towards the socket. You have buckleys of tightening it. If you then remove the bar & socket and place the socket on the wheel nut so that the bar now faces down at 30 degrees. Place your hand on the end again and push in the same horizontal direction and you will start to tighten the nut.

It is leverage - and when you raise a vehicle and the radius arm changes from 'close to horizontal' to angled then the forces being applied to the arm from the diff become alot greater. Hence any bump or undulation in the road creates a more dramatic movement of the axle. Bushes flex more and you get more 'forward and backward' movement of the axle as it moves up and down, momentarily changing castor. This creates poorer handling and feel than a vehicle at standard height or utilising drop boxes.

It is really up to you which one you choose depending on whether you want better on-road or off-road.

Hope this helps

Peter K.