vibra thing

[G-zilla]

whell I've got a problem whit my front drive shaft , first of all , thought is was the shaft it selfs so I bought a new one , nothing happens , when I'm driving over 70km/u ther is a noticeble vibration , You can feel it on the floor of the truck , when I remove the front shaft there is no vibration at all , and it drives smooth until topspeed , ,when I mount the shaft back the vibration is also back , the shaft is istalled propperly , does anybody knows where to search ? transfercase , front axel , or something else ? The vibration is ther in 2WD AND 4WD !

thanks to all of you !

[Roy Gardiner]

Have you checked the relative positions of the two halves of the drive shaft G-zilla?

If it came from MB I would it expect it to be correctly aligned.

I have seen correct alignment pictures shown here before, Dutch will know from whom no doubt.

Just a thought...good luck with your detective work.

Regards

[Roy Gardiner]

G-zilla,

Don't know if this is relevant to G's (?) but I do now that many 4x4's are sensitive to the mountings condition and correct angles for the transfer box.

The infamous Lada Niva (actually a great off-road performer) produced awful drive-line vibaration on the road, instantly cured by shimming the transfer box mounts with a washer - food for thought?

Roy

[Hipine]

If it shakes with a new shaft and not without, doing the easy stuff first, I'd check:
1- U-joint phasing (drive shaft article on CGW)
2- Transfer box mounting rubbers
3- Input flange parallelism to transmission flange

-Dave G.

[Karl Ingolfsson]

I remove the front shaft there is no vibration at all , and it drives smooth until topspeed , ,when I mount the shaft back the vibration is also back
MB 1982 300 GD
3 inch of lift
body-lift
winch
33x12.5-15 Goodyear MT/R

If your G has 3" suspension lift and the frame connection of the front radius arms is unchanged it MUST vibrate....

[Hipine]

What Karl is meaning to say is that a spring lift will rotate the axle drive flange to an angle that is no longer matched to the u-joint phasing and transfer case flange angle at neutral ride height. The nature of paired U-joints to induce and cancel cyclic variation of angular velocity will no longer be optimised if you use a stock drive shaft in that lifted configuration.

You MIGHT get lucky and find that one spline variation either side for the arrow alignment might help your situation, or maybe a full 180 degrees off. But it'd be sheer luck.

Since it's not hard to do though, I'd say try some alternate u-joint phasings.

I'd forgotten about your lift.

-Dave G.

[G-zilla]

so you say I have to change my U-joints , into CV-joints or something , I was thinking to put a spacer between the drive shaft and the TC or Axel drive flange (I've seen that on some toyota's and suzuki's) any other Idea's ?
Could italso be the ring and pignon ?

[Hipine]

The spacer when they lift those trucks is only a bad bodge to make up for the drive shaft becoming too short and possibly falling apart on full droop. Not a vibe thing.

Going to a CV joint at the t-cse end can solve your problem IF you can get the U-joint at the axle end to be straight (near zero angle). If there's angle in the front UJ, the CV won't fix the vibration.

Like I said, the other idea is to play with U-joint phasing by misaligning the arrows at the slider by a tooth or two.

-Dave G.

[G-zilla]

thanks for that info , I will try it tomorow in the afternoon !

I'll let you knopw what works !