(Home) Crankshaft pulley

A fellow Townie owner has informewd me that his crankshaft pulley fell off a few days ago, he attempted to get a replacement pulley from a breakers, this was wrong as it only had two grooves instead of three. To the main question what sort of damage do you think there may be to the crank & what are the remedies?

- (#8700) Arshad Mahmood, 23 May 03 7:39

Lots of stories and views on AceAnswers. Worst case the crankshaft needs replacing, best just a new pully, key and bolt required.

- (#8701) Clive, 23 May 03 8:00

Surely,two grooves are machined onto the pulley itself but, the third groove is the power steering pulley which bolts onto the face of the main pulley. Unless there is a model with a crankshaft pulley with three integral pulley grooves. Can anyone say if there is such a pulley on any of the many "Ace" models? As far as I know, the earlier pulleys has just one goove, with the bolt on p/steering pulley.
You might be lucky and find that only the keyway has some damage and, a newly made up key, fitting well, will be all that is required. I am a bit puzzled as to what happened to the pulley which dropped off. Was it damaged and abandoned and did the "bolt on" third pulley/groove not get taken off?
I would add to Clive's comment but, I would not fit another pulley without a locking device for this frequently unwinding bolt. It's simple to make and ensures that this expensive episode cannot happen again

- (#8702) John Davis, 23 May 03 11:47

Arshad,
I had the same problem getting a pulley for my Liteace.
Inner pulley - Air Con
Next pulley - 2 belts - Alternator
Outer pulley - Steering pump
David Miller, helpful chap that he is was able to identify the correct part numbers.
The older part number was 1340864050 for pre August 1990 vehicles.( This is your 2 belt pulley )
The new part Number was 1340864080 for post August 1990 vehicles. This is your 3 belt pulley and as John has indicated the steering pump pulley bolts on to the front of it, making a total of 4 belts !
Most important !!!!
Check that there are no remains of the old bolt in the crankshaft. i.e. The original bolt had broken.( Get a mirror and flashlight and look down the hole also Check depth with the new bolt. If I recall correctly it does'nt go fully home but its pretty close)
I had to remove the radiators, make a bushing and cut drills short, to enable me to drill the remains of my broken bolt out. I then had to buy a tap to clean the threads.
If the nose of the crankshaft is damaged use a good 2 part epoxy adhesive to fill the damaged area and dress with a file.
On rebuild DO NOT tension the belts with the threaded tensioners but rely more on leverage with a long screwdriver - I believe that over tensioning the belts is a major contributor to this as a recurring problem.
Check the archives for more info on this.
Costs
Pulley £190, Woodruff key 83P, Bolt £2.57, Washer £300 and you should get them all.
Tap for the crankshaft was £78 because they would only sell them as a set of 3 - fine medium and coarse because its an unusual thread.
- (#8703) Stephen Judge, 25 May 03 17:01

Arshad,
A most helpful and detailed contribution from Stephen and,apologies,in my posting I had overlooked the inner, air compressor pump pulley. Yes, three pulley grooves, with the fourth being a "bolt on" for the power steering pump. What interests me, being a bit paranoid about the pulley, when this disaster happens, does the pulley bolt usually unwind or, as in Stephens case, is it more common for the bolt to shear? Comments from other unfortunate owners would be helpful because it is difficult to imagine a bolt of these dimensions shearing if it has not been "bottomed" in the threaded bore of the crankshaft. I have made a locking device for my bolt and I know, by careful measurement, that the bolt does not bind in the bottom of the threaded bore but, no locking device can prevent the bolt from shearing. Might we have a situation here where the owners of vehicles which have lost their pulleys, might, unwittingly, be torquing the bolt into the bottom of the threaded bore, therbye setting up a shearing stress in the bolt? I know that there are different pulleys, some with only one groove for the alternator/fan drive. Could there be different lengths of bolts in use and, should everyone who fits the pulley, be reminded to check the lenghth of the bolt and the depth of the threaded bore? As I mentioned in my previous posting, on other vehicles, I think the motor trade would consider this a very unusual, almost unheard of phenomenon.

- (#8704) John Davis, 26 May 03 2:02

John, the cds show a number of different part numbers for the bolt, but as there's no spec, it's hard to work out what differences there might be.

As an aside, I've heard of a couple of instances of crank pulley loosening/ failure on Peugeot HDi engines...

- (#8705) david miller, 26 May 03 5:51

The reason for my first failure remains unknown but my second failure was my fault ( over torque ) as confirmed by a metallurgist friend who analysed the bolt. He suspects this was compounded by excessive belt tensions which set up additional forces.

- (#8793) stephen judge, 28 May 03 16:16

Thanks for your comment Stephen. Can I assume that when you lost the pulley for the first time, the bolt had unscrewed and become detached/lost ? I seem to think that this is the usual failure with the bolt and not a shearing failure as it was in your second pulley problem. Thanks for yours and David's comment on my original request and I still feel that careful checking of the bolt, it's length v the depth of tapped bore, together with a simple locking device, are important considerations when fitting these pulleys

- (#8794) John Davis, 29 May 03 1:22

John,
I agree 100% that some form of lock would be benificial.
On both occasions my pulley bolt remained in place. It was the vibration and knock at low revs, that got progressively worse, that alerted me to the problem.

- (#8843) stephen judge, 30 May 03 17:20

Hi all
I had this problem about one year ago and my local toyota dealer asked me for £2000 to replace crankshaft as the only solution to this problem...
However I asked to another garage and they did replaced the pulley and etc for just...£200 (ten times less)
If you are in the Bristol Area and you need this job done, mail me and I will give you the directions to the garage.
Luis

- (#8851) Luis Cebrian, 2 Jun 03 3:28