Drive shaft center bearing?

[Sundowner]

Hello,
A few weeks back I reported a clutch shudder problem in my Sprint. I had lots of replies for which I am grateful. At the time I said that the drive shaft centre bearing was in good shape and dismissed it as being the cause, or part of the cause.
But while beneath the car yesterday, I gave the drive shaft a shake and found that although intact , the rubber was soft-ish and the shaft could move about when shaken.
Is this normal?..... OR ...... should the rubber be firm, making it difficult to shake the driveshaft?
Is there a "measure" I can use to determine if it needs replacing?
Also, should I need to purchase a new one, I understand that there is a certain way its supposed to be installed. Could you advise me how please?
Thanks & Cheers,
Rob

[gmsclassics]

Mine seems reasonably firm in that it hardly moves with one finger pressure but moves a lot with a good firm shake. Having said that I've only ever replaced one and that was because the rubber was actually split, but wasn't causing any significant vibration. Any prop should be balanced so unless that has been mucked up - for example changing a UV joint and reassembling the front and rear sections in a different way - I suspect that is unlikely to be the cause of significant vibration

Geoff

[harvey]

Years back one of my customers had a terrible vibration on his Mk3 Cortina and that was cured when I fitted a centre bearing to the propshaft.

[Galileo]

I've got this how to by James bookmarked if it's any help?

https://forum.triumphdolomite.co.uk/vie ... 30#p267600

[Carledo]

If it's not split and the bearing isn't noisy, it's probably OK! They do move around quite a lot with a firm shake, at least within a week of fitting a new one! I've driven around for years on some VERY borderline centre bearings, so long as the rest of the driveline is OK, they will last well and not produce any untoward symptoms by themselves. It's only when another fault is introduced into the driveline, like a partially seized or knackered UJ or similar, that will cause "run out" in the prop, that they disintegrate! Some other makes and models (I remember the MkII Granada was particularly prone) seem to be very sensitive to the state of the centre bearing and it's alignment, but the Dolomite isn't usually one of them.

Steve

[Sundowner]

Gentlemen,
Thanks for answering.

I did notice from James's "How To" that the shaft has a constant velocity joint mid way. Mine has a universal joint.

There is no vibration problem, gents. Just clutch shudder when hot. While pulling away, or at worst, when backing uphill.

Geoff,
your centre bearing description fits mine, so I think I'll leave well enough alone.

Steve,
You were posting just as I was writing this up. That's exactly what I was hoping to hear. I'll definitely leave it alone then.

Again, Thank you.
Cheers,
Rob

[Carledo]

With reference to your clutch judder problem, there used to be a problem on some cars (notably Fords) called "clutch thrash vibration"

It first surfaced (at least on MY horizon) talking to old hands when I was a just a new apprentice and the earliest victims were MKI Consuls and Zephyrs. It turned up again in the 70s with the MKI and II Granada, and was initially blamed on prop alignment (hence the sensitivity I mentioned above) Eventually, an uprated clutch driven plate was produced by Ford which cured it completely.

It occurs to me that nearly ALL available clutches these days will be copies made with different materials (ie NOT asbestos!) so this could be a factor! I also remember that, back in the day, those of us "in the know" would go out of our way to get a Laycock made clutch for both Sprints and any "big 6" saloon Triumph we had to put a clutch in. The Laycock was quite a lot more expensive, but well worth it, in terms of longevity and smoothness of operation. I have no idea how to get hold of a Laycock clutch nowadays, but perhaps there IS a better alternative driven plate around somewhere waiting to be discovered, or from one of the aftermarket tuning companies like Larkspeed (who I know do compo clutches for Sprints, i've fitted one, not to my own car, and drove it on the RBRR, seems OK so far, but only done about 3k miles)

Steve