vibration when front hubs are locked?

[adamant]

ive got 6in tough dog lift, and im running drop boxes to fix the castor. The problem ive got is on the weekend i was down the snow, ive locked the front hubs and now ive got a virbration at about 80-90ks. So i unlocked them its fine again. So its in the front end, has anyone had this trouble? or know of it? any help would be appreciated, as its anoying the shit out me.

[GUHOON]

What vehicle we talking about.
Hows your front driveshaft?
is it hitting the xmember or your uni's might be shagged.

[rover1]

try leaving your hubs unlocked and go for a drive in high range 4wd, if its still virbrates look at your tailshaft (front).

[Sexy Fingers]

I've got the same kit in my car with 5 degree castor plates, but I don't have the drop boxes. Mine has the same problem. Looking at mine I reckon it's the angle of universal joints on the propeller shafts. I'm guessing your problem would be associated with the uni joints as well. One easy way to find out is to pull the propeller shaft off the car, lock the hubs and go for a drive. If the noise has stopped, bingo, problem found. I'm thinking of buying a gearbox spacer kit for mine. Would anybody have any feedback on these spacer kits? And what is the differance between drop boxes & spacer kits? (or can someone point me to a link explaining)

[rover1]

gearbox spacers will make the angle worse at the front.
drop boxes are better than caster plates but not as good as custom arms.
its a stuffed uni i reckon. you might find the front shaft is rubbing on the x-member with that much lift, you will have to take some metal out and give the shaft some clearance.

something like this, or just take to it with a big hammer.

[Sexy Fingers]

@ rover1. You've almost completly convinced me to take to my crossmember with an angle grinder. Just a couple of questions though. Is it that simple or will I need to do a cut and shut to reinforce the x member? How does this mod affect the structural integrity of the crossmember? and finally, even though my Patrol spends more time off the road than on, is it street legal?

Cheers

[SLOGQ]

Try turning your front tailshaft around so that the thinner end bolts to the gearbox. I have 5 inch coils and drop doxes and it clears the crossmember since i turned it round. I had the same vibration to by the sounds of it.................

You can do this to the rear one to.

[BIG GQ]

gearbox spacers will make the angle worse at the front.

Think about it man. Not the case. Why was the idea put in place to run gearbox spacers then? because they sit between the crossmember and the chassis and lower the gearbox which in turn puts the shafts at a less severe angle.

[rover1]

i have both my shafts turned around, rear clears most of the time, except when airbourne...

i did mine using some 75mm pipe with a 4mm wall, just what i thought would be enough out and added pipe in, and cut down to suit. i can still get to the nut for the gearbox mount with a 1/2" socket set.

as long as you weld something in place of what you cut out it will be as strong as before. as for legal, dont know how this could effect anything to make it illegal, if the cops pick you on that you must of pissed them off bad.

[rover1]

gearbox spacers will make the angle worse at the front.

Think about it man. Not the case. Why was the idea put in place to run gearbox spacers then? because they sit between the crossmember and the chassis and lower the gearbox which in turn puts the shafts at a less severe angle.

if you space the gearbox down, it will make the flange on the transfer case point upwards, not much but still making the angle worse at the front

[GUDamo]

Hey adamant

Mate, I've got the same problem. I think it is the angle of the front tail shaft too. I brought my Patrol standard with only 10,000 on the clock & had no noise or vibrations with the front hubs locked but soon as I did the lift I got the bad vibrations. I've checked & the tail shaft is not hitting anything. Being auto locking hubs it's fairly easy to just unlock them when I go over about 70kph. Pain in the ar*e I know. To bad if I wanted to use 4wd over 70 or 80kph. I'd really like to know if there was any way of fixing this problem too...

[JemmyBubbles]

gearbox spacers will make the angle worse at the front.

Think about it man. Not the case. Why was the idea put in place to run gearbox spacers then? because they sit between the crossmember and the chassis and lower the gearbox which in turn puts the shafts at a less severe angle.

if you space the gearbox down, it will make the flange on the transfer case point upwards, not much but still making the angle worse at the front

True. The transfer is connected to the... gearbox.... the gearbox is connected to... the donk.. (Sing it)..

You are lowering the rear most section down and as has been said this kicks the front drive flange up, thus worsening the angle...

[Jimbo]

Yeah mine does it too and i only have a 4" lift. I was thinking about putting gearbox spacers but havent had time. I just dont drive over 60km/h in 4wd....i dont find a need to

[Sexy Fingers]

gearbox spacers will make the angle worse at the front.

Think about it man. Not the case. Why was the idea put in place to run gearbox spacers then? because they sit between the crossmember and the chassis and lower the gearbox which in turn puts the shafts at a less severe angle.

if you space the gearbox down, it will make the flange on the transfer case point upwards, not much but still making the angle worse at the front

True. The transfer is connected to the... gearbox.... the gearbox is connected to... the donk.. (Sing it)..

You are lowering the rear most section down and as has been said this kicks the front drive flange up, thus worsening the angle...

Yes I thought that was the case. I don't suppose anybody does modified engine mounts to drop the engine down as well? And before anybody says it, I know it sort of defeats the purpose of lifting it in the first place

[adamant]

yeah just went out and had a good look at it, the drive shaft clears the cross member by 25mm, it spins freely but the angle on the unis on the transfer case is on a big angle! any body got any bright ideas how to fix it? thanks for the feed back

[adamant]

sorry forgot to mention its a gu tray back with 16000km on the clock, and the lift went in 2000km ago