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Guest

Hi guys,

Usually on here as bw but can't find my login details just now Sad

Last night the P4 started vibrating at low speed, and making strange almost metallic noises whilst turning on hard-lock. I'm worried this is a problem with the viscous coupling maybe seizing up or something like that Shocked

. Earlier in the day I grounded the car on a speed bump, but I think that only touched the exhaust so may be unrelated???

Anyone had this happen before, what would the symptoms of a knackered coupling be?

Or any other possible causes you can think of please?

P4 Paul · Posted: Sat Mar 13, 2004 10:12 pm Post subject:

possibley your propshaft cv's,or you centre mount bearing?

Buck Bundy · Alfasud Joined: 30 Oct 2003 Posts: 68 Location: Anglesey

It isn't likely to be the viscous coupling, unless you can see evidence of damage to the casing. It would probably need a good knock to damage it.

There is very little to go wrong with the viscous coupling itself, except for physical damage or leakage. If all the fluid leaked out I think it would just stop transmitting drive to the rear, rather than seize. Have a look at the coupling mountings, and the prop U/J and bearing as Paul said.

Could it be the rear diff'? It is possible for that to seize if it looses its fluid.

Good luck

Buck
_________________
Sprint Veloce 1.5 - Ebay £310!!! (In need of TLC)

Guest · Posted: Mon Mar 15, 2004 10:52 am Post subject:

Thanks guys. Forgive my ignorance but would there be any physical signs of a damaged or worn out CV? Is it safe to drive, or is there some way I can disable the 4wd until it can be repaired...think I read somewhere there's a fuse I can take out which disables it but might have made that up Rolling Eyes

Buck Bundy · Alfasud Joined: 30 Oct 2003 Posts: 68 Location: Anglesey

You're right, there's a fuse which will isolate the magnetic coupling stopping drive to the rear.

I can't remember where it is though! I seem to recall it being with the other fuses.

If you do this, and still get noise, then it could be the gearbox (ahead of the mag coupling) or the rear diff.

Do viscous couplings wear out? Apart from physical damage, and wear to the mountings, I don't think there is much to go wrong.

Buck
_________________
Sprint Veloce 1.5 - Ebay £310!!! (In need of TLC)

JamesD · Posted: Tue Mar 16, 2004 12:30 pm Post subject: P4 noises

The fuse is part of a relay mounted on the cross member between the front strut towers. On a right hand drive car it is on the left, just in front of and to the left of the battery. Removing the fuse will dis-able the drive to the rear wheels, but the propshaft etc will still turn as the car moves. (The 4x4 fail light will illuminate when the fuse is out.) You may still have noises if the universal joints/bearings are stuffed.

Check the rear diff oil level by removing the filler plug on the back side - the level should be up to the hole.

My P4 makes various noises depending on the tyre pressures. Pressures correct - very little noise, rear press low - lots of noise from the gear backlash just chattering to itself especially when under no load (ie not accelerating!)

Have fun!
JamesD
33S16V P4 (phew!)

Guest · Posted: Tue Mar 16, 2004 2:06 pm Post subject:

This is good info, cheers. Haven't had chance to look at it yet. One thing that intrigues me is that the car was at the Alfa specialists only 10 days ago and I asked them to check all the gear and diff oil levels etc. Now I'm wondering if maybe that is related - what if they forgot to put a plug back in or something and the oil got low. Anyway, no use speculating now, I'll have to take a look when I get chance.

thanks again

Ben