DC Tailshaft vibrations. why/how/what?

[DEFENDER DEN]

Hi all, I have just put in my new TW front double cardan tail shaft in my puma and now I have vibrations at around 2200-3000 rpm in all gears. I have tried the old coil springs and still the same. Has anyone come across their DC shaft vibrating?

[Grappler]

I had a problem with a Tom Woods shaft that I put in my Disco 2 a few years ago. It vibrated from new.

Took it to a drive shaft balancing outfit in Perth and they needed to straight and rebalance it!

[BilboBoggles]

I would have thought that if it's vibrating at specifc RPM's in all gears and not at a specific speed, then whatever is vibrating is rotating at engine speed. So that means it may not be the prop shaft. In my experience if it's vibrating at a specific RPM band its probably something like a engine to chassis contact issue, or a flywheel etc.

What sort of vibration is it, a rough harsh high pitched vibration that you feel through the steering wheen could be a intercooler hose rubbing on the steering shaft, perhaps that was dislodge by the mechanic?

[jools]

I experienced similar vibrations after installing a dc shaft on my puma 90.
Went through all the balancing of shaft etc but shaft was well within tolerances.
Turned out to be a distorted flange at the transfer box.
Replaced with new flange and vibrations vanished.
Hope your fix is as easy.
Cheers
Mike

[DEFENDER DEN]

Hi. Thanks for the replys you can feel the vibration through the steering wheel, dash and gear stick. It is like a growling sound but unlike the binding sound that the old shaft made when it was binding with the extra bit of lift
Did you have any indication of vibrations prior to changing over to a d/c shaft from the old shaft before the t/c flange was replaced.
Cheers

[jools]

Before my 2"lift there was no vibration at all with the standard shaft.
I was well aware that after a 2"lift to a Defender 90 a D/C was required so at that time I had Hardy Spicer fit a heavy duty D/C front shaft. There were no vibrations at all.... it just felt very tight for the first 500kms. Now the story...
Alas, their installer did not use Loctite at T/C.
Just 3,000km later when I was miles from anywhere ( in Limmen National Park near Roper Bar, NT) the tailshaft came loose from the T/C.
Due to the endless corrugations, I did not notice until a smooth patch of track. Upon inspection the bolts to flange were held in place by less than quarter turn...and due to the movements and friction the shaft and flange were glowing red hot. The lower D/C joint was totally destroyed so rest of trip was completed with front shaft removed.
Back in Townsville, Hardy Spicer made and fitted a new shaft but it was then that a vibration as described by you was felt through steering, dash and gear lever.
After removing shaft and rebalancing many times (they even sent shaft down to Brisbane to be checked) they noticed that there were heat stress marks on T/C flange which was found to now be distorted They replaced flange with genuine replacement part and the vibrations totally disappeared and that was 4000kms ago.

[jimr1]

I suppose the way to tell if It is a shaft problem is take It off , engage central diff lock and drive It . if the vibration has gone It could be the prop ! If the vibration is still there then It's not a prop issue . Next would be to be happy that It is balanced ok. If It is and the vibration is still there , then as some of the other's have found , It's the output flange . One word of advice , put new nylock nuts on , they're cheep !!.. cheers Jim ..

[Yorkshire_Jon]

Maybe a silly question, but what end do you have the DC joint? Needs to be at the T/Bo end.

Also, how long is the shaft? It's not over extended on the splines is it?

[DEFENDER DEN]

Thanks for the replys. Further fuel for the fire when I push the clutch in all quiet. No vibration. I am now thinking that the small extra weight of the D/C is causing the vibe's somewhere. The D/C end is at the T/C end and around 690mm long with plenty of spline in the shaft.
I will get around to checking the output flange one day with a dial gauge . Other than that my head is getting sore and the brick wall is still standing. Cheers

[steveG]

When you push the clutch in and it goes quiet, are you holding the revs up at the problem rpm or just letting it idle? I agree with Bilbobiggles - if its engine rpm dependent its most likely not the shaft.
Is it just rpm, or also varies with engine load?

Steve