GU Vibration after lift

[mr nismo]

Hoping somone can tell me whats going on. I havee a GU wagon, and had a 3" lift untill saturday when I fitted a set of 4" springs. I have castor bushes fitted and its driving fine but I have a very slight vibration, more so under load, and a very slight rumbling sound when at around 80kmh whilst coasting.
I am guessing it is a tailshaft angle problem.
I have not fitted adjustable panhards yet, but will be in the next week or so.
Could this be the cause?
Or would it be more likely I need longer trailing arms?
I didnt have a vibration untill the springs were fitted, or will it get better as they settle?

Cheers
Dan

[stool]

Sounds like you need a gear box spacer 5 or 10mm

[Nelso]

Hoping somone can tell me whats going on. I havee a GU wagon, and had a 3" lift untill saturday when I fitted a set of 4" springs. I have castor bushes fitted and its driving fine but I have a very slight vibration, more so under load, and a very slight rumbling sound when at around 80kmh whilst coasting.
I am guessing it is a tailshaft angle problem.
I have not fitted adjustable panhards yet, but will be in the next week or so.
Could this be the cause?
Or would it be more likely I need longer trailing arms?
I didnt have a vibration untill the springs were fitted, or will it get better as they settle?

Cheers
Dan

Spot on. Your uni's are out of alignment. Longer lower control arms will fix it.

[Suspension Stuff]

Instead of getting longer lower control arms you are better off getting shorter (adjustable) upper arms. Bigger tyres will hit on the rear guards if you get longer lower arms.

It wouldn't hurt to get new lower arms the same length because of strength issues if you plan to go off road and hit an arm on rock or something.

You won't need the gearbox spacer.

Shane.

[unimog]

DO THE FRONT WHEEL VIB IF SO IT IS THE SPACE'S ON TOP OF THE KING PIN'S TAKE THEY OUT AND PUT THEM IN THE BIN AND GET NEW KING PIN'S HAD A GU WITH 2 AND 4 AND 6 INC LIFT

[KIWI]

I personall y went longer lowers as they are weak, so fixed 2 problems.
No problems with guard clearance with mine.

[mr nismo]

Thanks for the replies. I am going to fit longer control arms, and cross my fingers. I would like them anyway so they are stronger.

Thanks again.

[Nelso]

GUs have much bigger wheel arches than GQs, so unless you're running real big rubber you should be fine.

[mr nismo]

I am going to buy some snake adjustable lowers, is there any tricks to fitting the arms and do I need to get a wheel alignment when they are fitted to get them straight or just measure with a tape? I guess if I adjust them so that the spring seats on the diff are flat again it should be where I need it??

Thanks
Dan

[Suspension Stuff]

I am going to buy some snake adjustable lowers, is there any tricks to fitting the arms and do I need to get a wheel alignment when they are fitted to get them straight or just measure with a tape? I guess if I adjust them so that the spring seats on the diff are flat again it should be where I need it??

Thanks
Dan

Keep the uni joints parallel.

If you think about it, when you are fully compressed off road you will be roughly 15mm longer for the lower control arm for a 4-5" lift so your tyre will be pressed up against the rear guard and with 35" tyres there is a good chance of not just rub but stuffed guard.

If you don't go off road and flex it up you will be fine.

Shane

[bushy555]

[quote="4WD Stuff a 4-5" lift so your tyre will be pressed up against the rear guard and with 35" tyres there is a good chance of not just rub but stuffed guard.[/quote]

Angle grinder will fix that...

[Suspension Stuff]

[quote="4WD Stuff a 4-5" lift so your tyre will be pressed up against the rear guard and with 35" tyres there is a good chance of not just rub but stuffed guard.

Angle grinder will fix that...

Then you are good for 37's

[Nelso]

I am going to buy some snake adjustable lowers, is there any tricks to fitting the arms and do I need to get a wheel alignment when they are fitted to get them straight or just measure with a tape? I guess if I adjust them so that the spring seats on the diff are flat again it should be where I need it??

Thanks
Dan

Keep the uni joints parallel.

If you think about it, when you are fully compressed off road you will be roughly 15mm longer for the lower control arm for a 4-5" lift so your tyre will be pressed up against the rear guard and with 35" tyres there is a good chance of not just rub but stuffed guard.

If you don't go off road and flex it up you will be fine.

Shane

Don't think you'll have a problem with a GU and 35s. GQs need a bit of trimming to run longer lowers but GUs have huge wheel-arches in comparison.

For the record -Richo- just fitted 35s to his GQ that only has a 2" lift and didn't need to trim any guards or run radius arm spacers or bump-stop extensions on the rear and he doesn't even have the quarters chopped.

[Suspension Stuff]

I am going to buy some snake adjustable lowers, is there any tricks to fitting the arms and do I need to get a wheel alignment when they are fitted to get them straight or just measure with a tape? I guess if I adjust them so that the spring seats on the diff are flat again it should be where I need it??

Thanks
Dan

Keep the uni joints parallel.

If you think about it, when you are fully compressed off road you will be roughly 15mm longer for the lower control arm for a 4-5" lift so your tyre will be pressed up against the rear guard and with 35" tyres there is a good chance of not just rub but stuffed guard.

If you don't go off road and flex it up you will be fine.

Shane

Don't think you'll have a problem with a GU and 35s. GQs need a bit of trimming to run longer lowers but GUs have huge wheel-arches in comparison.

For the record -Richo- just fitted 35s to his GQ that only has a 2" lift and didn't need to trim any guards or run radius arm spacers or bump-stop extensions on the rear and he doesn't even have the quarters chopped.

With a 2" lift you are not running longer lower control arms by 15-20mm.

[mr nismo]

I was really after a method of how to change the arms over?
Do I need to put stands under the car etc or just undo the bolts and drop it out?
I am guessing I need to do 1 at a time?

Cheers
Dan

[mr nismo]

Well I have had an interesting time with this one! I fitted some snake racing adjustable lowers, and have adjusted them so the pinion is paralell, I measured from the top transfer flange to the top pinion flange and the same on bottom, and ended up with the same measurement, and still had a vibe. I tried adjusting them in and out 5mm at a time and the best position is 20 mm longer than standard. I got my adjustable panhard and fitted it and was fixed I thaught, but its not, I still have a slight vibe, well its like a very low pitched rumbling sound.
It is a GU 2.8 with the alloy case gearbox and the small diff, and all other GU wagons I have seen with big lifts around, have standard everything and are having no vibes. Everyone I speak to about it says I dont neeed a gearbox spacer on a GU LWB, and say they dont know why I have a vibe. I had a 3" lift prior and no vibes, now 40mm higher and its shagged!
The one thing I have noticed is th slip joint on mine is pulled out 70mm, and another GU with a 7" lift I saw today, I looked and his was only pulled out about 30mm. I dont know if it has anything to do with it but its really starting to bug me. I thaught it may have something to do with the fact its a 2.8 motor and could be different to others cos its got the different box and diff, but I have spoken to other 2.8 owners and they have bigger lifts with no drama.
I have 2 tailshafts, 1 spare, and they are both the same.
The shaft was taken back to Hardy Spicer today and checked for balance, with the slip joint pulled out to 70mm same as in the car and came out fine. The unis are 12000 kms old and are in perfect working order.
All this started when I fitted the new springs, its was fine withg the 3" lift.
Anybody have any suggestions?? Its got me buggered

[Suspension Stuff]

I had the 2.8 Turbo diesel GQ with a 3-4" lift. I found that the tail shaft would hit on the cross member in certain situations but this won't be causing the vibes, just a tip.

Somebody else will have to chime in about the 70mm in the tail shaft but it seems too much to me. The movement alone means it is different to where you had it.

My suggestion from the start was to get standard length lowers and adjustable uppers. You may be better off getting adjustable uppers just so you can shorten that 70mm gap. I am not certain this is causing your problem so we are better of waiting for someone else to speak up.

I assume it is part time 4WD???? Otherwise the front could be causing some probs.

Shane

[mr nismo]

Its a GU Patrol, so yes it is part time., and my tailshaft has been turned around for a while now so it cant hit the crossmember.
I am not convinced it has anything to do with the arms, upper or lower, as it didnt really make much diference, and all the other GUs I have seen with big lifts have all standard gear under them, pinions pointing upward almost the same angle as the tailshaft, so thats what I dont understand why mine needs them especially mine is only 4"?
I have a feeling it may be perhaps a bearing somewhere and with the extra lift it has changed the angle and the sound is radiating differently?
I dont know Im only guessing?
Thats why Im asking on here as I know others have had these problems in the past, and I am hoping someone has had the same experience, or know someone who has.

[zerko]

Is there excessive play in the slip joint. Not length wise, but twisting-wise.

Is the slip joint greased up?

[GU_247]

I have a feeling it may be perhaps a bearing somewhere and with the extra lift it has changed the angle and the sound is radiating differently?
I dont know Im only guessing?

You will find the unis are more than likely have a bit of wear
A gearbox spacer will fix the problem
However the best solution is to replace the unis

[mr nismo]

The slip joint feels good. No play in either direction. The unis are relatively new,like 12000 kms old.
I had the shaft checked yesterday at hardy spicer moorebank and they gave it the ok as well, and even checked it for balance on the machine with the slip joint pulled ot 70mm to simulate whats going on in the car.
I tried packing down the gearbox 10mm, but it seemed to make no diference.
It doesnt matter which shaft I put in the car (I have 2) it still does the same thing, so I think its the angle of the shaft, or the slip joint being pulled out so far, or not the shaft at all, but it did only start as soon as I put the bigger springs in from 3" to 4".
Does everybody else with a GU have their slip joint pulled out so far?

[zerko]

Can you remove the tailshaft all together, run the car to 80kmh in 4WD and see if the vibe is still there. At least that will eliminate if its the tailshaft or not.

[mr nismo]

OK I will try that tomorrow, the vibe only starts at 70kmh geets worse at 80 kmh, bit better at 90 kmh same at 100kmh and then pretty much goes at 110 kmh.
I was going to change my muddies for my stockies tomoz as well just to see.

[mr nismo]

Well its pissing down rain taday so taking the shaft out and going for a drive is on hold.
Just a quick question, after looking at it and thinking more about it, I think the pinion needs to go down a little more.
If I wind my lower arms out longer it will push the diff back more and pull the slip joint out more, and possibly the tyre will grab the guard on compression.
My question is if I shortened the lowers back to standard length, the slip joint will go back in the same amount. If I buy adjustable uppers, and shorten them it will bring the pinion down, but what I want to know is will the slip joint get pushed back in or will it get pulled out more? I dont like the fact the slip joint is only engaged by bugger all as it will wear very fast so I would like to fix it properly.

Cheers
Dan

[Suspension Stuff]

Adjusting in the upper adjustable control arms doesn't make as much difference to the tail shaft length as the lowers do.

Even after adjusting them in the tail shaft will still be longer then original because of your lift.

I am certain you aready know this but the idea is to keep the universal joints parallel, this is how to phase out the vibes although you may have stumbled on another reason you get vibes, being the slip joint. I don't have experience with this so I can only presume same as you. I am certain others would have a similar setup though. Snake sells bucket loads of those arms.

When you adjust it, it does look all wrong.

Shane

[mr nismo]

Yesah I figured the lowers needed to be lengthened more to acheive the same thing?
I am going to borrow an angle meter to make sure the angles are right first.
What do you mean by all wrong?

[zerko]

There is always this http://72.34.32.141/~snakerac/product_i ... 60fa5df22d

[mr nismo]

But I shouldnt need a longer slip joint on a GU with only 4 " of lift???
Should I???????????????
And at $550 to buy the slip joint, I may as well get the shaft lengthened for $300.
I still think it is the angles.
It bugs me though that I look at these other lifted GUs and the pinion is up in the air, pretty much paralell to the shaft, and the angle on the gearbox end is massive, and they get no vibes???????
WTF just my luck!

[unimog]

the vibe in the front end is the spacers above the king pin trust me been there before . and the rear tail sharft angle should be about 10 deg's down bubble off the angle of the tail sharft so when you put the boot in to it . it will level up . try the front space's i went and done all that and then did that it's gone