Can anyone give clear, accurate direction for removing Access. Idler and S/C Idler bolts??? I see Access. Tensioner is REVERSE (L.H. thread), Right to Loosen, and S/C Tensioner is (normal) Left to Loosen.

Again, need Access. Idler and S/C Idler directions to LOOSEN/REMOVE bolts.

Thanks.

 

Hi,

the only reverse threaded bolt on the pulleys is from the accessory drive belt's tensioner pulley (turn clockwise to loosen).
All other bolts (from pulleys, brackets etc.) on the drive belt's components are normal threaded (= turn anti-clockwise to loosen).

Cheers, Alexander

 

Alexander--

Thanks for ALL the info and pix !!

SCREECH at 3000 rpm. Had both belts (Access. Drive and S/C) checked for wear and tension. S/C Idler (smooth) was smudged with S/C belt (back-side) residue. Cleaned S/C Idler contact surface and replaced S/C belt with Jag OEM belt...no change. Next is replace ALL 4 sets of Idler/Tensioner bearings.

Any other suggestions, tips ??

Ed

 

If the contact area of the idler was covered with belt residuals, then it's likely that the other pulleys are too. When changing my belts, I cleaned the grooves of the ribbed pulleys too. With a flathead screwdriver I scratched out all the residues...and it had been some!
So my thinking goes that if your grooves are filled with belt residuals then your belt is likely to slip because it's contact area to the pulley is reduced.

 

After reading through this thread, I am even more confused than I was prior to reading it

Recently, I decided that I wanted to replace my supercharger tensioner and belt, as well as the tensioner and belt for the accessories. I ended up buying all of the parts from a seller on eBay, who bundled them all together in one listing for me. He sent me the supercharger tensioner, accessory tensioner, supercharger belt (double-sided,) and the accessory belt. He also sent me the idler bracket ($100) for the supercharger belt. He said it was required for an update that Jaguar did. He wasn't sure what the update was, but he thought it had something to do with the pulleys being switched over to metal instead of plastic. I told him that all of my pulleys were already metal, so the update must have been done. But I went ahead and had him send me the bracket anyway, in case I needed it. He said I could return it if I ended up not using it. He also mentioned that I needed a new idler pulley, but I told him that I would wait to see if the existing pulley had any slop in it before buying a new one.

Long story short, when the parts came in, and the old parts were removed, I compared them to each other. All of the accessory belt parts were spot on. But I immediately noticed an issue with the supercharger parts. My existing tensioner for the supercharger has a metal, ribbed pulley. The tensioner that he sent me has a smooth metal pulley. So I sent him an email asking if he could send one with the correct pulley. I also mentioned that the idler pulley did have some slop in it, and I would need to buy a replacement from him. After that, I took a look at the new supercharger idler bracket. To my eyes, it looked the same as the one that was on the car. That made me happy, because it meant that I could return it.

On Monday morning the seller responded to me, and said that the tensioner he sent me was the correct one for my car. He also said that I DO need that new idler bracket. Can anyone tell me what the difference is between the new version and the old version? As I said, they both look the same to me. Just to double check what he said, I checked PartsGeek for the supercharger tensioner. They list BOTH versions, which really didn't help me to figure out which one was the updated one. At that point I was fairly confused. So when I came home from work, I started reading threads about the supercharger belt setup. In this thread, the OP states that his original idler pulley is smooth, and the new replacement that he was able to find was ribbed. My current idler pulley is smooth. Now I'm even more confused. Why would the new tensioner have a smooth pulley, and why would the idler be ribbed? (which, presumably, is the reason that the new belt is double-sided) That seems backwards to me. Why would you have the ribbed portion of a belt contacting a smooth tensioner pulley? Doesn't that reduce the amount of surface area on the belt that is gripping the pulley?

In closing, I would like someone to answer the following question for me: As of right now (April 23rd,2018,) what is the CORRECT configuration of the supercharger drive system, including all updates, for a 2002 XJR?

 

Latest revision, also used on the 4.2L, is a double sided belt, smooth tensioner and a ribbed/flanged idler with the slightly modified mounting bracket. JTB00045NAS3 - Drive Belt Noise - Repair Procedure.pdf the attached bulletin outlines the changes to the 4.2L cars, but in the end the same has been fitted to the 4.0L as well.

 

I was also initially confused with the changes made but, after reading a lot of information, I concluded the following:

1. With one-sided SC belt: smooth idler pulley, ribbed tensioner pulley.

2. With double-sided SC belt: ribbed idler pulley, smooth tensioner pulley (this is what I have on my 1999, VIN 87+).

3. There could also have been a combination for a one-sided belt: ribbed idler pulley, ribbed tensioner pulley but I am not sure about it.

It seems that Jaguar tried various combinations to eliminate belt squeaking. I don't see any problem in belt ribs riding on one smooth pulley (as long as other pulleys have ribs to keep its position) or the smooth back of the belt riding over pulley ribs. With the ribs-smooth combination, the chance of the belt squeaking is much smaller.

As for the SC idler bracket, there are two different part numbers with a change point at VIN 853936. I presume this was the change from plastic to metal so the idler pulley bracket should be same for the later metal pulleys, smooth or ribbed, but the best thing is to compare them and measure in detail, especially the height of its centre part to which the pulley is attached.

 

Thanks guys! But I still think it's strange having the ribbed portion of a belt riding on a smooth pulley I've never seen that before. So once I get the new (ribbed/flanged) idler pulley, I will have a completely updated supercharger drive belt setup. I just need to look around for the bolts that hold the s/c idler bracket in place, as well as the s/c idler pulley bolt, so I can replace them when I put the new bracket on.

 

The idler has a special bolt to centre it.

 

Looks like the idler pulley comes with a new bolt

 

if this is for your 100, then the car already had the updated (4.2) pulleys. The cheapest and fastest way to renew these revised pulleys is as I've mentioned earlier in this thread...
(I updated my 100's, and many cars since)
https://www.jaguarforums.com/forum/x...71/#post443012

 

While my 100 did have all metal pulleys when I bought it, it did not have any of these updated parts that I'm putting on (flanged and ribbed idler pulley, smooth tensioner pulley, slightly different bracket, and a double-sided belt.) I just need one more piece, and my car will be fully updated. If these new updated parts ever go bad during the time that I own the car, I will go ahead and just replace the bearings. But that will probably be for the next owner to do.

 

It does 😉

 

Wanted to thank everyone in this thread who helped out.
Bought idler and wasnt the one I needed when arrived (but will replace anyway) and looking at the parts/schematics I only go tmore confusededed. About the first thread that came up and now it all makes sense. Ordered the new bearings and hopefully back to new soon.

Thanks!!