Outer Limits 4x4 Board

Has any body done this on a swbpajero? Aparantly its common on lifted swbpatrols to help decress the angle of the rear prop shaft to help stop vibration through the drivetrain.
Ive come to the conclusion thats what my vibration could be. Can anybody tell me will i have any other problems if i drop my front cross member about 7-8mm.
cheers
Glenn

WHAT why? you have IFS. Your front drive shaft doesnt change angles.
Please explain your vibrations.

Going by your sig line you only have a 2 inch suspension lift - this is not going to be the cause or your vibration.

If you think it's a drivetrain problem then start with the uni joints on your rear prop shaft. Check them for movement or excessive heat build up after driving, pump them full of grease and take the car for a run around the block to see if the vibration has been reduced.

Explain the vibration - does it happen under power or when you back off or all the time. Can it be felt "through" the car or mainly through the steering wheel.

Lowering the crossmember ain't gunna do jack.

Sorry not the drive shaft (will correct) it will help the angle of the rear prop shaft. When I did the lift it was a total of 60-65mm from memory but It probably is only a genuine 50mm as the old springs may have saged a bit.
Ive just had a second hand transfer case put in and 2 new uni joints and the viration is still there.
The vibration is through the whole car ,comes and goes through the rev range in each gear. vibrates around 2.2-2.6k rpm and 3.5- 3.8k rpm.Play havic with you ears somrtimes.
If I put it into 4wd the vibration goes away. Any ideas
Cheers
Glenn

Your not talking about the front crossmember then, your talkin about dropping the transfer case like the jeep guys do.

I am curious if it will vibrate still when you pull the rear shaft and drive in 4wd 2wd.

Wheel bearings ?????

OK, now we've got a better idear. Since you have a SWB, it could be the rear tailshaft angles. Maybe you could load up the back ( say with cement bags or some such) so it brings it down by 50mm than see if you still get the vib's. But I suspect you may have worn uni joints.

A come along will do the trick.

I have found 3 litre shafts to be weak, [soft], and the yokes can be pressed out of true when fitting UJs causing the driveshaft to not spin true.
J Top

I'm sure you checked this, but with the philosophy of simple things first, wheels out of balance/broken tire belt/bent rim?

Yeh, ive had 2 mechanics try and find the problem and couldnt and put it down to the lift. I have tried packing the car full of weights and tyrs but only droped 20mm and didnt really see any differance (maybe a little).
So does anybody know if it would do any harm if I lowerd the front cross member 6-7mm to lower the transfer case angle.
Cheers
Glenn

It shouldn't do any harm apart from lower your ramp over angle so give it a go although I can't see it fixing the problem. I originally lifted mine 3" in the back which has come back down to 2" after settling - that was nearly four years ago and any vibrations have usually been chased back to uni's or bearings (mainly due to lack of maintenance and too much mud).

Spacing the trafser case cross member down shouldn't take long and it's another thing to cross off the list if it does not work.

Bent or out of balance rear prop shaft??

Rotate the front tyres to the back and make sure they are all up to the same (and the correct) pressure.

Rear wheel bearings (make a deeeeeep) pulsing kind of hum that can be felt through the whole car.

Its got band new uni joints so its not them.
Would wheel bearings cause a contant vibration through the full rev range when driving or could it cause a vibration that comes and goes through the rev range? This vibration I have vibrates around 2.2-2.6k rpm and 3.5- 3.8k rpm but is ok when cruising.It also does it with both sets of tyres and wheels so I have ruled them out.
The vibation reduces about 90% when I put in 4wd which makes me think its something to do with the prop shaft.All the weights are still on there and doesnt look bent.

Might sound funny but have a real good look at your engine mounts, gearbox and transfer case mounts. Even go to the point of taking them off the vehicle one at a time and checking them.

Get a 2nd hand prop shaft from a wrecker or meet up with an OL member and try a shaft from someone elses car if they are up for it - slabs or beer help here.

Any play in the front end ???? tie rods ?? drag link ??

You just put in a 2nd hand t/case ??
Did the vibes start after that ??
If it did then it could be the output shaft main bearing or too much slop on the slip yoke.

With a 3" lift on a SWB your D/S is probably too far out of the transfer, I just fitted a 20mm spacer to Lugs Loves Mud
J Top

The vibe was there before the new transfer case and with the old uni joints.
The transfer case mount has drooped about 2-3mm but was told it wouldnt cause that vibe that is in the car.All other mounts seem ok.
Jtop, may try that, maybe I just need a 10mm spacer. Can I just use washers as a spacer? I do get a leak of oil dripping off the transfecase dust cover were it connects tp the prop shaft so I am now wondering if the pop shaft is being pulled out slightly. This also happen with the old tansfercase.

I had an old holden years ago it developed a vib did everything to find it ( balanced d/shaft wheels everything) wnen i got to the diff I got it lapped and told my woes to the guys he mentioned the bearings put new ones on and wulla no more vib bearing cost $35 but i spent about $500 trying to find the cause look in to it

Why not pickup some stock coils and put them in drive on them for a day and see if the vibe goes away?