XJ40> Modern secondhand Jag parts. Good supplier found.

[J44EAG]

These guys are great. Needed a good secondhand top serpentine belt idler pulley and didn`t want to buy new.
http://stores.ebay.co.uk/Auto-Reserve-T ... 707?_rdc=1

Andy is the man to speak to and his service has been excellent. He was most helpful when I phoned him. I`ll certainly be doing more business with him.

A trawl on ebay turned up just what I was looking for. New about £70 and seemingly almost impossible to source other than from Jaguar. So this pulley came to me as a "buy it now" second hand item with P&P for just under £13. Bargain The pulley is in cracking condition having covered about 54k miles, is clean, smooth running and not falling to bits like the one on my car. Considerable wear was noted at around 75k miles and the fitted pulley now sounds rough and noisy. Time to be swapped out. I understand this item is unique to the V8 S-type and will not fit K8 or J8 models.

As I see it, fitting will need the belt displaced by easing the bottom sprung tensioner and the belt then slipped off the water pump pulley. A centre bolt secures the upper idler pulley to a mounting shaft. The pulley may then be teased off the shaft and replaced.

Interestingly, i`m sure the centre sealed bearing would be available from antifriction parts suppliers and could be easily drifted out and replaced from new. The part number on the bearing is HSR S 86 on one seal face and HSR S 53 on the other. I`ll research this when I next have an anorak moment.

Fitting pics in due course.

Mike

[latebreaker]

Good work Mike.

Be handy if they had a set of 19" Barcelona wheels....I'll have a butchers.


Krish

[Martec]

Hi Mike,

A local Car breaker (Scawby spares) and Jaguar enthusiast put me on to Auto Reserve last year when I was looking for a full size spare wheel and other bits. I found them very helpful and very cheap (my sort of supplier).

Brian

[robv12]

yep used these guys as well, of course we also have Euro Jag to turn to, who I have to say have been brilliant recently with my never ending wants list!!

[J44EAG]

Changed this pulley now.

This top idler pulley is something of an odd ball. Remember I said it had a wobble which I put down to advancing age and mileage.

These pulleys are not cheap when new so I obtained a good secondhand one. Arming myself with a pulley extractor for removal, I started the job. Removed the air cleaner and trunking to the throttle body. At that point the pulley is easily accessible. Using a torque wrench with 3/8 drive adaptor I moved the sprung lower pulley against the tension spring and slipped the drive belt off the water pump pulley. Then with a 13mm socket on a ratchet, slackened off the pulley bolt. After a few turns the pulley became loose on its mounting. Removing the long 13mm bolt completely allowed complete removal of the pulley. I felt this a very odd build.

What I found was a collet which was internally threaded and could be moved along the length of the mounting bolt to run at any point along the length of the bolt within the internal diameter of the pulley bearing. It does not appear to serve much purpose apart from centralising the bolt in the centre of the bearing. With the collet screwed a little below the rear face of the bearing, that face then makes proper contact with the mounting on the timing cover. With the bolt tightened against a washer at the front of the pulley, all the wobble is now gone. No more nasty noises from the front of the engine. Job done.

I found the bearing on the car to be in excellent condition. Be that as it may, I swapped out my old pulley for the secondhand one I had acquired as it had covered 30k miles less than the one fitted to my car.

So what was the issue with my pulley and why did it wobble? Simple. The internal clooet had been fitted pround of the rear of the pulley bearing by a couple of mm. This meant that although the bolt was tightly torqued to the engine, the pulley rear bearing face was not in proper contact with the front register machined onto the front timing gear cover.

Now with 87k miles on the clock, J44 must have had this slight issue since manufacture. In other words this pulley hadn`t been fitted correctly at build stage. It doesn`t help does it? Fortunately no damage caused but I now have a secondhand pulley available and a small gear puller kit neither of which I now need. May be the gear puller kit will come in handy on some other future engine project.

In my efforts to be prepared for all eventualities with this pulley change, I went ahead and bought the puller kit and replacement pulley. I didn`t want a dismantled car kicking about whilst I sourced parts and materials. Had a good old fashioned Haynes manual been available I could have researched the job before buying a replacement pulley or taking the precaution of buying the gear puller set. No info on the internet on this issue either. So £30 as an unnecessary spend. Not the end of the world and the wobble and noise has gone.

Mike

[oldtimer]

Hi Mike,
Well, that's another job done and dusted. Well done. If I understand your description correctly, it sounds like a pretty dreadful bit of engineering. I can add this to a number of other, what I call dubious design features that I have come across on this vehicle.

I have to admit to being an admirer of Isombard Kingdom Brunel. Yes lets put in another six nuts and bolts in case - as opposed to - well, an elastic band should last a while.

Oldtimer

[J44EAG]

On this item, Phil, I would like to have seen a stub shaft on to which the bearing is better supported along the axial plane.

As it is, the rear face abuts a circular flat top hat sub with about a 3mm location register. The inner tube race is unsupported and relies on an 8mm bolt thread which at the front end passes through a large washer with minimal location value. A 13mm bolt head is to the front of the washer. Centralisation of the bolt within the tube inner race is by way of the threaded collet.

In practice this pulley has been trouble free with no reports rendered of any recurrent issues on the 4 litre V8. However it does rely on that odd collet being wound down the bolt to below the back edge of the tube race to seat correctly. Thinking on the subject again now and attempting to reverse engineer the design concept, I wonder if that collet should be located towards the centre area of the inner race bearing. That would put rather more support to the bolt towards the front of the pulley. ie in the centre of the belt run where forces would be distributed in the manner of clockwise moments equaling anticlockwise moments with a uniformly distributed and more balanced load potential being achieved.

What concerns me slightly is the fact that a side load force is applied by the lower tensioner to tension the serpentine belt. The centre bolt is not of 2% carbon variety being made of a rather softer material which could easily bend due to cantilever side loads imposed. I suppose it is adequate unless of course the collet and bolt arrangement adjustment is incorrect. Hopefully my adjustment of the collet and bolt will put the whole unit into safer limits than previously which allowed the pulley to wobble when the engine was running. I thought I was daling with a worn bearing. In the event the problem was cured by minor adjustment.

Mike