Propshaft vibration

[DavidW]

Driving home from Kent to Derbyshire last week, 'Mellow Yellow' developed quite a vibration when slowing from 70mph to 65mph. It felt like it was coming from the transmission and a good friend of mine in the club says its most likely the propshaft.

I've been looking at repacements, and see I have a choice of two:
LD Parts offer a solid one without the rubber elastomer joint https://www.ldpart.co.uk/shop/shop.p...8fdd84ce67cf02
and Rimmer and EJWards seem to offer the origional version with the rubber elastomer joint.

My question is - LD say its almost imposible to get the propshaft with the rubber elastomer joint to balance. Is this correct, and has anyone had experience of fitting either of these?

[richardthestag]

I had no end of bother with various props (new and used) when I had a BW35 fitted. Had the gearbox not expired and been replaced Man o/d I might have gone down the solid tube route

[sujitroy]

im in us. and bought a cv jointed one from Rimmer have not fitted. cost was a factor with with shipping to USA. it is for a manual
my bw35 auto was rebalanced I asked the guy about the rubber and he said it was ok.on two manual prop shafts I have the spines were worn. too expensive to fix here

[Lingen]

David.
Before you go to the expense of buying a new propshaft, why not get the U/Js checked. It could be that one has failed, and a small garage with a decent workshop should be able to fit a replacement. In fact if that is the problem, it would be sensible to replace both of them. If the positions of everything are carefully marked up before removing the old ones, it shouldn't put the shaft out of balance.
Mike.

[Mark S]

David.
Before you go to the expense of buying a new propshaft, why not get the U/Js checked. It could be that one has failed, and a small garage with a decent workshop should be able to fit a replacement. In fact if that is the problem, it would be sensible to replace both of them. If the positions of everything are carefully marked up before removing the old ones, it shouldn't put the shaft out of balance.
Mike.

I replaced the joints in my shaft when I converted to manual and the balance was way off. Rimmers sold me one of their CV shafts at a very good price and it has been as smooth as silk and no problems in 10,000 miles.

I'm not anywhere near an outfit that balances shafts but for the cost of two universal joints, then pay a small garage to fit them and then have your prop balanced would probably be uneconomical compared to the price of a new one. If you have someone close that has the equipment to balance propshafts it would probably be cheaper to hand the whole thing to them to recondition.

I would get underneath and have a good swing off the prop and drive shafts to see if you can find where your problem is.

[Bakdraft007]

I just did one of my UJ's (gearbox) recently. I too had a vibration and also a clank when rapidly applying power in reverse or forwards. When I got it off it was clear there was a bad joint... there were no rollers left inside it just rust crumbs.

It was a really hard job for many reasons:

1. Getting access to everything underneath of axle stands was difficult
2. Getting the exhaust apart was difficult
3. The UJ circlips snapped... difficult
4. The UJs did not want to press out difficult
5. The new ones did not want to go low enough in for the new circlips difficult and stressful
6. The bolts on the prop-shaft were really difficult to access and could only be move by small amounts at a time..neck so stiff
7. The exhaust mounts were difficult to reassemble with the small amount of room

It was all in all such a pain that I had bought both to change but only ended up changing the clear fault one... as I though if the other one is as difficult to change I might end up with no prop shaft

That said once done it was fine... and It save me changing the propshaft and the UJ's are cheap.

Dave

[Alacrity]

Just a thought, and its probably not relevant for this thread, but we had a customer bring a Stag in for a bad vibration at speed, BW35 auto. We could find nothing wrong apart from the two gearbox sump to engine backplate braces being both missing, Suggested to the owner That he may want us to fit them & see if it helps, he said no but he would look into it himself. Anyway about a month or two later I saw him at a show & he had fabricated a couple of braces & the vibration stopped instantly.

Perhaps not relevant here but may help someone in the future.

Geoff

[JOHNS]

The old trick for balancing prop shafts used to be to mark the prop shaft circumference at 1/4 intervals about 100mm from the uj and fit one or two jubilee clips. You then drive the car and note the vibration. You then keep moving the clips around the shaft until you have eliminated the vibration. I have never tried it so cannot verify that it works.

[MandM]

I make this little jacking tool to push the exhaust apart so the prop would come out easily between the boxes, as john said have a go at balancing it with a clip but mark the prop so you know where you have been with the clip
P1080540.JPGP1070905.JPG

[Lingen]

One (or two) other things to check. Make sure the flanges bolted to the diff and the overdrive haven't worked loose. A bit of slack in either of them can cause the problem.

[ramjam2005]

After a catastrophic failure of the diff at speed (actually..the quill shaft bearing seized), I had it replaced along with new driveshafts. I returned to the garage that had done the work a few times after as kept experiencing a vibration. Mechanic said everything with the drive train and the propshaft UJ's looked fine. Not satisfied, I removed the propshaft and meticulously inspected it myself. The source of my vibration - a hairline crack in one of the yolks !!

I was supplied with a replacement prop which I had rebulit and balanced. No more vibrations !