Strange Rattle noise...possibly prop area?

[silverbullet]

I think I'll have a word with Reco-prop over at Feltham and see what's available. There's no excuse not to have damped tubes if you're having a prop made with DIN90 (?) yokes.

[v-lux]

I'd personally be interested in the results of all this. I sent my prop off for a full refurb a while ago and albeit in very nice condition upon return (joints all lovely and smooth, repainted and looking like new) i'm not sure if they replaced the bushing in it as it still rings like a church bell. No vibrations from it whatsoever though.

I'd love to get rid of that ringing, drives me bonkers.

[..lee..]

had my prop done the other day. there are spicer joints available that have pads in the ends of them to controll this. did the trick with mine nice and quiet now even with the tdi

[ragnarhairybreeks]

The propshaft is approx 8 cm in diameter, so something on the outer surface would be experiencing a force of 715 G when shaft is rotating at 4,000 rpm. If one guesses that the propshaft wall is about 3 mm thick, then something on the inner wall would experience 661 G at 4,000 rpm. So I'd guess that whatever foam material you choose to fill the shaft with should be resistant to collapse under these forces.

Amazing G forces eh? No wonder Harry had problems keeping the mastic panels on the outside surface.

cheers

Alistair

[HarryMann]

Yes, I did have problems keeping them stuck on... but it was silent as a lamb to start with

did the trick with mine nice and quiet now even with the tdi

Lee, its the Tdis isn't it, that are much less of a problem than the AAZ's ? Or it seems none of the Tdis I've been in rattle their props anything like my idi diesel.

[lloydy]

I get that ringing bell noise from my prop, notice it more when driving down a narrow road as it rebounds off the houses. Would like to get rid of it, Can you still buy the props new?

[silverbullet]

Mr Baxter will be happy to relieve you of a parcel of monies in exchange for one!

[HarryMann]

Why dost thoust think a new prop will resolve this noisome nuisance Lloyd? Could it be that prop is just the messenger of , not the source of said tribulation.

[lloydy]

if i was certain, i would have bought one by now To be honest though, not much else it can be. Over the last year or so everything else has been replaced, at least once Its made the noise since i've had the van, low speed when lugging the engine

[HarryMann]

Over the last year or so everything else has been replaced, at least once It's made the noise since i've had the van, low speed when lugging the engine

Ditto.... including a new GKN prop that sounded even worse But have to admit I haven't tried a brand new VW ones, but other used ones, which have made a difference, but not a full cure.

This was about the quietest, while it lasted...



Have you tried:

a) switching it around (to petrol position) ?
b) putting two (exactly diametrically opposed) pairs of jubilee clips around it, at two positions, 1/3 and 2/3 along the tubular section length, or exactly midpoint *
c) large diameter heat-shrink *

*as you can see, I did 1/3 1/2 and 2/3 with the panel deadening bitumen based sheet

I am sure there are much higher quality self-adhesive sound deadening mat'ls than that Frost stuff I used, in fact i know there are, which may give a much longer term result. I think it lasted a few weeks; one of the wraps a month or more ...

[ragnarhairybreeks]

Harry,

I experimented with some bitumen impregnated, self adhesive fabric a few weeks ago. I started (and did not get any further) with a section in the middle of the shaft. I did not notice any difference when driving, but I can't say whether that was due to the relatively lightweight fabric or just having it on one place.

But... the adhesive partially failed during a short drive. A portion of the fabric came loose and was hitting the protective rails. Imagine a playing card in the spokes of a bike wheel amplified 1000 X. Was an incredible noise and vibration from such a (seemingly) small bit of material


alistair

[HarryMann]

Mine did same Alistair, but not quite such a din as that. Could just about tell that the stuff was delamming or coming off from time to time (it actually stayed on well for much longer than I imagined) Would think with a heat-shrink sleeve over it, with the care I took overlaying, cutting and flush fixing the edges, it'd be perfect enough to last and last. Job has to be 100%, degreasing, laying on etc.

The actual test is hill climbing and letting revs drop too far (down to 1200 rpm and below ) before changing down, that's where I alwasy get the rattlle, exacerbated by the ratio spacing on the T3 diesel boxes, now got a 'V' box in mine with diff ratios twixt 2nd & 3rd, but of course, now we knw why so many modern diesels have 6-speed boxes... even more so with direct injection Tdis, they ahve a very narrow usable/workable rev-band...

much like so many of those classic two-stroke screamers of the 70's and 80's

[dave friday]

Hi Harrymann,in the picture of your damped prop the orentation of the uj looks wrong [90deg out?] is it the picture?
Best regards,Barry.

[HarryMann]

No very std., they're at the required 90 degrees at opposing ends.

[jebiga41]

Just to resurrect this thread just saw a post on the yahoo Syncro group

I've gotta say, after 150,000 miles in my syncro, that I must agree with Daryl and Insyncro. Any time I had any prop-shaft related vibrations, with the three different shafts I own, it was fixed by re-build and high speed balance..bad u-joints being the problem....and bad builders/rebuilders.
> I had a brand new Burley shaft go bad on me with-in 600 miles of installation (actually, it was bad out of the box, but thats another story). That thing destroyed the out-put shaft seal & bearing on my de-coupler, and I'm fairly certain it wiped out my front diff as well.
> The "go-westy"; slip-yoke shaft I'm running now was rebuilt locally twice, re-installed and removed immediately more than twice, due to continued vibes. On a whim, I finally sent it back to the guys at Driveline Services in Oregon (the ones that built them originally for go-westy) and its been perfect again, ever since. Again, bad u joints....on a twice freshly rebuilt shaft!
> I don't want to steal anyones thunder regarding angles and alignment but for me, on my van non of that stuff ever made any difference at all. I've run shims, no shims, cranked the front diff laterally as far as it would go to both sides, had three different motors (stock, zetec, 1.8T), vc's and straight shafts, decouplers and not. None of those variables changed anything...ever.
>
> Mark