Aircon belt tensioner/Crank pulley

Livermpj · 18th March 2012, 17:31

After being laid up for 18 months (the car, not me), I'm finally preparing the old 75 for the road

The front bumper's off to fix cooling fan, so I thought I'd do the belts as they're 11 years old.

As usual nothing's completely straight forward

I'm now wonding if this'll turn into belts + tensioner + crank pulley

I checked the bearings and the crank pulley by hand when the belts were off, everything felt smooth & tight so I fitted new belts and tensioned the A/C belt.
Running the engine I noticed a faint rattly sound in the belt area - then discovered I can rock the plastic A/C tensioner wheel when it's under load. It feels OK when it's unloaded though(?)
Before replacing the tensioner, I'm now thinking the crank pulley could cause the belt to become over-tensioned...

I've noticed the crank pulley is pulled slightly off-centre by belt tension. When running it seems to self-centre and run almost true, but not quite. I had a few grumbling noises from the belt area before I laid the car up, only from a cold start though, and only for the first minute or so.

Does anyone know how to daignose a failed crank pulley/damper?

Also is it normal to have a bit of movement in the plastic A/C tensioner wheel, even though it feels tight when unloaded?

Advice & experiences welcome, I'd like to try and get to the POL if poss.
Thanks, Pete.

T-Cut · 18th March 2012, 19:04

If tensioning the belt with the tensioneR system pulls the crank pulley off-centre, then the crank pulley needs replacing. The rubber interleaf is well known to deteriorate until it allows the outer part to start clanking on the inner part. Your isn't that far yet, but it soon will be.

There should be no sideways movement/slop in any of the pulleys, jockey or tensioner wheel. Any which show it should be replaced.

TC

COLVERT · 18th March 2012, 19:41

Crank damper ???

T-Cut · 18th March 2012, 20:27

Quote:

Originally Posted by COLVERT

Crank damper ???

Same thing. The pulley acts as a torsional vibration damper by means of its rubber interleaf construction. Yes the Freelander TD4 pulley seems to be identical and somewhat cheaper.

Compare Rimmer: http://www.rimmerbros.co.uk/Item--i-GRID001733

with British Car Parts: http://www.britishparts.co.uk/.sc/ms...SHAFT%20DAMPER

There may be cheaper suppliers of this Part Number LHG100750L

TC

Livermpj · 19th March 2012, 11:58

Thanks for the answers chaps, I think I'll change the pulley now whilst it's all accessible.

One thing bothers me though, and that's how to lock the crank/pulley.
I don't much fancy locking the starter ring-gear, as surely I'll be twisting the crank way beyopnd its design limits?

I've seen a picture somewhere of a special tool to lock the castellated hub on the pulley. Is this something that's readily available, or if not, has anyone got some good tips to make a heath-Robinson version?

Cheers,
Pete.

T-Cut · 19th March 2012, 15:16

This is the tool

And how it fits

They are available from tool specialists for about £80.

I doubt if Heath Robinson would cut the mustard. There's a good photo of the locking head in this thread: http://www.the75andztclub.co.uk/foru...=12-177&page=2

TC

James.uk · 19th March 2012, 15:34

Crank pulleys can "go" very quickly. So best to get it replaced..

E.G. .. I called into my local garage (social call) and the mechanic said the pulley was noisy, and told me to bring the car in the following morning. I had noticed nothing at that point.

Went home (3 miles) on the way back next day the engine started making a hell-of-a-row...

Got to the garage, and when they got the pulley off it was in two pieces... the inner ring could rotate without the outside one moving!!

...

Livermpj · 19th March 2012, 18:24

Hmmm, ran the engine briefly with no belts attached, and the pulley rattles...
As the car's already in bits, I'd prefer to do the job myself.

SO... Is there anyone in the Notts/Derby area who has a pulley holding tool, and who might consdier hiring it out, with a cash deposit just-in-case?
I treat tools with care and respect, so any prospective deal could be done with confidence

The good news is everything else on the car (so far) looks good. Glad I gave the underneath a good de-rust & wax seal a few years back, and kept the paintwork waxed, it makes repairs seem more worthwhile

I suppose rubber deteriorates regardless of whether the car's being used or not.

Thanks,
Pete.

18th March 2012, 17:31	#1
Livermpj Loves to post Rover 75 CDT Club saloon Join Date: Nov 2006 Location: Nottingham Posts: 280 Thanks: 0 Thanked 3 Times in 2 Posts	Aircon belt tensioner/Crank pulley After being laid up for 18 months (the car, not me), I'm finally preparing the old 75 for the road The front bumper's off to fix cooling fan, so I thought I'd do the belts as they're 11 years old. As usual nothing's completely straight forward I'm now wonding if this'll turn into belts + tensioner + crank pulley I checked the bearings and the crank pulley by hand when the belts were off, everything felt smooth & tight so I fitted new belts and tensioned the A/C belt. Running the engine I noticed a faint rattly sound in the belt area - then discovered I can rock the plastic A/C tensioner wheel when it's under load. It feels OK when it's unloaded though(?) Before replacing the tensioner, I'm now thinking the crank pulley could cause the belt to become over-tensioned... I've noticed the crank pulley is pulled slightly off-centre by belt tension. When running it seems to self-centre and run almost true, but not quite. I had a few grumbling noises from the belt area before I laid the car up, only from a cold start though, and only for the first minute or so. Does anyone know how to daignose a failed crank pulley/damper? Also is it normal to have a bit of movement in the plastic A/C tensioner wheel, even though it feels tight when unloaded? Advice & experiences welcome, I'd like to try and get to the POL if poss. Thanks, Pete.

18th March 2012, 19:04	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,754 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	If tensioning the belt with the tensioneR system pulls the crank pulley off-centre, then the crank pulley needs replacing. The rubber interleaf is well known to deteriorate until it allows the outer part to start clanking on the inner part. Your isn't that far yet, but it soon will be. There should be no sideways movement/slop in any of the pulleys, jockey or tensioner wheel. Any which show it should be replaced. TC Last edited by T-Cut; 18th March 2012 at 19:07..

19th March 2012, 15:16	#6
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,754 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	This is the tool And how it fits They are available from tool specialists for about £80. I doubt if Heath Robinson would cut the mustard. There's a good photo of the locking head in this thread: http://www.the75andztclub.co.uk/foru...=12-177&page=2 TC Last edited by T-Cut; 19th March 2012 at 15:26..

19th March 2012, 11:58	#5
Livermpj Loves to post Rover 75 CDT Club saloon Join Date: Nov 2006 Location: Nottingham Posts: 280 Thanks: 0 Thanked 3 Times in 2 Posts	Thanks for the answers chaps, I think I'll change the pulley now whilst it's all accessible. One thing bothers me though, and that's how to lock the crank/pulley. I don't much fancy locking the starter ring-gear, as surely I'll be twisting the crank way beyopnd its design limits? I've seen a picture somewhere of a special tool to lock the castellated hub on the pulley. Is this something that's readily available, or if not, has anyone got some good tips to make a heath-Robinson version? Cheers, Pete.

19th March 2012, 15:34	#7
James.uk Passed Away 2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles Join Date: Dec 2008 Location: Near the M67. Posts: 14,509 Thanks: 199 Thanked 585 Times in 397 Posts	Crank pulleys can "go" very quickly. So best to get it replaced.. E.G. .. I called into my local garage (social call) and the mechanic said the pulley was noisy, and told me to bring the car in the following morning. I had noticed nothing at that point. Went home (3 miles) on the way back next day the engine started making a hell-of-a-row... Got to the garage, and when they got the pulley off it was in two pieces... the inner ring could rotate without the outside one moving!! ...

19th March 2012, 18:24	#8
Livermpj Loves to post Rover 75 CDT Club saloon Join Date: Nov 2006 Location: Nottingham Posts: 280 Thanks: 0 Thanked 3 Times in 2 Posts	Hmmm, ran the engine briefly with no belts attached, and the pulley rattles... As the car's already in bits, I'd prefer to do the job myself. SO... Is there anyone in the Notts/Derby area who has a pulley holding tool, and who might consdier hiring it out, with a cash deposit just-in-case? I treat tools with care and respect, so any prospective deal could be done with confidence The good news is everything else on the car (so far) looks good. Glad I gave the underneath a good de-rust & wax seal a few years back, and kept the paintwork waxed, it makes repairs seem more worthwhile I suppose rubber deteriorates regardless of whether the car's being used or not. Thanks, Pete.