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Hi Everyone,
I've got myself a pleasant Jaguar XJR (Supercharged 4L Straight 6)
The Supercharger Belt "Popped Off" Last Night and I've purchased another one to fit now....
The Pulley arrangement is fairly Straightforward... Obviously Main Pulley coming from the Engine... Winding around to an "Adjuster Pulley" with a Plastic (No Groove's) Guide Pulley finally finishing attached to the Supercharger Pulley itself....
The Belt itself is fitted and turning over ok....
Couple of Quick Questions
1) When I complete a slow increase in Rev's from Idle (All in Neutral) everything sounds fine in normal. However if I do a sudden increase of Revs I get a "Belt Slipping/Screaching Noise". Is this Normal for a "New" belt as part of some sort of bedding it process?
2) The Smooth Plastic Pulley doesn't seem to Spin completely freely. Should it be completely "Freewheeling" or should it have some resistance as well.
3) The Adjustable Pulley moves up and down on a Single "Adjusted Theaded Bolt". I've adjusted this so the Belt is pretty much as "Tight and Taut" as humanly possible. Is this what should occur.... Could the Noise mean I need to tighten further?
if you tighten it as much as humanly possible then that's to tight.. you can where out your supercharger front bearing.i wud back off a bit..and check.. if pulley you are talking about is the supercharger pully then yes it will have resistance from the rotors in the super charger.. and belts dont usually fall off unless they brake off.. i wud check for play on the tensioner pulley.
but idlers pulley shoud spin freely.. by hand with no belt on of course.. and have no play in it.. if there is replace it..
When I took the supercharger belt off on my xjr6, I can rotate all the pulleys freely without any noise. I can hand turn the supercharger pulley as well. The plastic pulley contains bearing inside and you can torque it down per spec. The belt tension adjustment should be done 1) loosen the bolt on the adjuster pulley, 2) turn the adjustment rod for the proper tension and 3) torque down the bolt on the adjuster pulley. Check all the pulleys and the belt alignment to see if they are all inline.
The idler pulley bearings if the same for the separate A / C compressor belt shouldn't last forever , 13 dollar ( Pre - Covid , PC ) common Gates # X
The center bearing bolt should have no effect on clamping the bearing too tight but has to be loosed in order to adjust the long treaded adjustment bolt
The treads can be frozen inside the treading block and let me know if yours is the same as I overcame that obstacle
There is a cheap belt tension gauge and the spec should be somewhere
To test the existing tensioner pully get some grease in the bearing and see if it disappears , temporary test fix
A sweak can also get in the area of a harmonic balancer slip ( under load ) with easy test
You don't have to remove belts for test , pic from AL as I don't have the SC engine
03-08-2008, 03:25 AM
RE: Jaguar Supercharger Belt Fitting (1995)
