Shredding Fan/Drive belts

[mwtryan]

My '98 Chim 500 has developed a nasty habit of shredding it's fan/drive belt - i've gone through 4 in the last 2 months!

It only happens at high revs/speed and basically the belt seems to move forward and shred the leading edge of the belt.

All the pulley's seem aligned and fine and in good nick etc.

Has this happened to anyone else? - Anyone got any ideas?

All help/advice will be welcomed.

Cheers.

[mongoose]

check your pulley alignment again.i cant see how it could be much else when happening with such regularity.pay particular attention to the crank pulley and inspect it very closely.crank pulleys on these engines have been known to move and fly off,a recent thread on here revealed that this does seem to happen a lot more frequently,it appeared, on '98 cars for some reason.

[GreenV8S]

It may be a problem with the pulleys not being parallel rather than being 'in plane'? Or perhaps a knackered bearing allowing something to wobble?

[2 Smokin Barrels]

One of my Chimaeras ate up belts. Main crank pulley was out of alignment.

[flintstone]

I've noticed my fan belt has a tendency to jump the idle pulley (where the PAS steering pump would be) by one groove. This only happened after I replaced the old pulley.

It looks to me like the pulley is too far forward by (coincidentally) about the thickness of the engine lifting, plate, hole, thingy. As I've no plans to hoist the engine out in the near future and it can always be refitted should the need arise I'm going to remove it.

[Painey]

I had the exact same problem last year on my 95 Griff 500. It left me stranded a couple of times after shedding the fan belt but only after I'd driven it quite hard. What seemed strange was that it was fine until I started to use the higher revs, then it was literally a matter of time before the belt got wrecked!! I keep a spare fan belt in the boot at all times now!!

I took the car to Austec who diagnosed that the idle pulley had moved forward slightly, thus making it not line up correctly. Just to confirm, that's the one furthest to the right when looking at the front of the engine on mine. Quite an easy fix and they secured it so it couldn't possibly do it again.

Hope this helps, cheers - Chris.

[flintstone]

Painey, any idea what they did to fix it?

[Painey]

Not sure really. I gather it had something to do with taking the idle pulley off and then refixing it with something a bit stronger so that it couldn't move forward again. Alignment of it was all checked as well and haven't had any problems since.

Sorry if that doesn't help very much, all I cared about at the time was that it was fixed!!

[deeen]

Mine was touching a jubilee clip, see if any look a bit close, turn them round so they are as far away as possible

[seasider]

Check your engine mounts

[deeen]

Good point S-S, have had mine changed since then!

[mwtryan]

Found the problem - the main bottom pulley seems to be slightly buckled - only saw it when we unhooked the coil and turned the motor over slowly. Obviously at high revs this will cause the belt to wobble nastily and become damaged. Either the pulley is not on right (unlikely) or it has indeed become buckled. Either way it's coming off on monday and hopefully will be sorted.

Thanks to all contributors - at least know what to do to prevent this happening again.

[Flintstone]

Mine only started doing this after I changed the idle pulley so I'm hoping for an easy fix.

[flintstone]

And the easy fix was.......................

Put the idle pulley on the right way round. The word 'Front' stamped on it should have been a clue

[jamer]

2 Smokin Barrels said:

One of my Chimaeras ate up belts. Main crank pulley was out of alignment.

was that the dodgy one you sold to me


Actually Dom and jamie at TVR Power re aligned the pulley, it had been like it from new.

As the engine is fairly simple you should be able to get someone to do it locally.

better still email TVR Power direct

[2 Smokin Barrels]

jamer said:

2 Smokin Barrels said: One of my Chimaeras ate up belts. Main crank pulley was out of alignment. was that the dodgy one you sold to me Actually Dom and jamie at TVR Power re aligned the pulley, it had been like it from new. As the engine is fairly simple you should be able to get someone to do it locally. better still email TVR Power direct

Yep, but the papier mache chassis was the real problem

[victormeldrew]

The first fettle my 500 required as delivered was to get the pulleys aligned after it ate a belt at 500 miles. One was not parallel. It doesn't take much for them to get eaten up.