Strange Rattle noise...possibly prop area?

[Aidan]

GKN Driveline at Leek
I have had their own made ones before, sliding joint and standard din90 ujs with grease nipples less than £200 and I recently had two shafts refurbished by them after my attempts had failed, you can fit a trunion kit from baxter but they don't necessarily come right without some black magic to sort end float and balance, as I have discovered,they did 2 for £135 plus vat in 24 hours sorted and repainted. I delivered and collected they are just over an hour from me, but I'm sure they can sort shipping/collection if required but good to use local if possible. GKN have more than 1 depot anyway, it was Andy Simpson who found the Leek one and pointed me at it.

[syncroandy]

Ditto, thumbs up for GKN driveline, very good service. I have a similar GKN prop in my pickup, it still has that 'ring' though. I think the steel tube it just acting as an amplifier for 'take-up' elsewhere in the driveline.

GKN Driveline at Leek
I have had their own made ones before, sliding joint and standard din90 ujs with grease nipples less than £200 and I recently had two shafts refurbished by them after my attempts had failed, you can fit a trunion kit from baxter but they don't necessarily come right without some black magic to sort end float and balance, as I have discovered,they did 2 for £135 plus vat in 24 hours sorted and repainted. I delivered and collected they are just over an hour from me, but I'm sure they can sort shipping/collection if required but good to use local if possible. GKN have more than 1 depot anyway, it was Andy Simpson who found the Leek one and pointed me at it.

[syncroand101]

GKN Driveline in Leek did mine, think I used Parcelmonkey to ship there. Accepted credit card over the phone, can't for the life of me remember how much it was, wasn't too dear though - had both UJ's replaced and it balanced:

GKN Driveline Ltd,
Higher Woodcroft,
Leek,
Staffordshire,
ST13 5QF

GKN Driveline Service Ltd

+44 (0) 153 838 4278

[HarryMann]

I have a similar GKN prop in my pickup, it still has that 'ring' though. I think the steel tube it just acting as an amplifier for 'take-up' elsewhere in the driveline.

That's it... Any tube will have several natural resonances, 'bell', 'organ-pipe', 'whirling'', bending etc

Our props being thin-walled accurate steel tubes have several strong ones, and probably two that combine (bell and pipe)...

The diesel engine partic. has torsional vibrations that excite these. I reckon one is about 140 Hz, a right clanging sound when you let revs drop below 1200. I've stood underneath in pit with someone just dropping clutch to take drive up and if there's any play at all (always will be) the ringing is like being in a bell-tower - almost deafening!

I bonded some bitumastic panel deadeners at the 1/2 ND 1/3 node points as an experiment and it was a real joy, quiet as a mouse, but they soon came off due to cent.force, starting at the corners.

There is a solution, just takes a bit more engineering to keep them on without losing balance (prop turns at crankshaft speed)

[HarryMann]

https://club8090.co.uk/wiki/Sy ... ifications

[ragnarhairybreeks]

Hi,

I've been fooling around trying to make new bushings for the propshaft. I managed to get both replaced and the fit of the yoke shaft into the housing is nice and snug. But assembly is not road tested yet and I have no idea how durable a fix it is.
Longish story of the process here: http://shufti.wordpress.com/2012/06/06/ ... -part-one/" onclick="window.open(this.href);return false;

and second part, bushing install successful here: http://shufti.wordpress.com/2012/06/06/ ... gs-part-2/" onclick="window.open(this.href);return false;

Now, please be gentle with me, there is plenty to criticize about what I did, believe me I've been nagging myself through the whole ordeal.

cheers

Alistair

[Simon Baxter]

We carry GKN rebuilt ones on the shelf.
Ready for next day delivery.

[Simon Baxter]

Oh, and GKN don't have a supply for the rubber coupling..
When we send a prop down to them they also get a new rubber coupling to fit... something extra you get on a Brickwerks/GKN prop rather than a GKN prop.

[HarryMann]

Alistair, that looks some handy chisel, a bit like a nut & bolt getter-offer




Here's mine... (screw/bolt punch)

But that bushing job looks a black art, but very successful, quite an achievement, right down to using that shimstock to funnel the bush past the step (if that's right), so

I'd like to link your article to the Wiki page we have here

https://club8090.co.uk/wiki/Sy ... eplacement

and/or here:

https://club8090.co.uk/wiki/Sy ... _refitting

please?


Thanks for posting this up

[ragnarhairybreeks]

Thanks for the kind words Harry. Of course you can link away, but I'd like to add the provisos of:

1. it is not road tested yet, let alone long term testing
2. much easier to buy a new shaft
3. real machinists will cringe

The little chisel is a handy little bugger, I haven't had to use it on nuts/bolts.... yet.

cheers

Alistair

[silverbullet]

There is a solution...

Has anyone ever considered filling the prop with structural PU foam to damp resonance? Not the usual builder's stuff, I'm talking about the non-contracting 2-part marine type they use for filling yacht masts. Mass is negligable so any accidental voids that result from filling won't throw the balance to any appreciable degree, a post-fill balance check might be worth the inconvenience nonetheless.

[jes*b]

In the spirit of experimentation I have a prop on the shelf that I could throw in the mix, spare one came in van

[ragnarhairybreeks]

One thing about the PU foam idea is that if the shaft does need balancing (then or later), welding on balance weights or spot heating to straighten might melt PU at that spot and confuse the balancing process.

cheers

alistair

[silverbullet]

What about props that have a cardboard tube insert to damp them? Common practice with British cars in the 60's and 70's and they have balance weights spot (resistance) welded on with no problems.
The foam is so low-density I can't imagine it would cause a problem. Fire-retardant too IIRC

[HarryMann]

One thing about the PU foam idea is that if the shaft does need balancing (then or later), welding on balance weights or spot heating to straighten might melt PU at that spot and confuse the balancing process.

I thnk Alistair has a point, most turn to an ugly (and much denser) loaclised mess at fairly lowish temps 150 up... so could upset things further. Cardbaord wouldn't usually of course; like wood sustaining a good deal higher temps.