Tonight I changed the drive belts on my 2002 XJR 4.0L V8 Supercharged. Checked the wear indicators on forehand. They still had a little bit to go. But I have a few long drives across Europe coming up in the next couple of week.

So I decided to change them out. I have done it in the past once or twice before. Both the supercharger as well as the accessoire drive belt as Jaguar calls it. Fairly straightforward. Although the JTIS claims you can remove the supercharger belt by just pushing the tensioner out the way. If you use this method the belt becomes slack. You can certainly pop it of the idler pulley but it still gets stuck. There is no way you can actually get it out. Nor would you be able to get the other belt off easily. So I always loosen up the tensioner of the super charger(just one bolt) and I take the shroud with the two fans out. (just undo two bolts and two connects). Gives you a lot more room to work and even then it is still pretty confined.

Anyway I had ordered new belts from SNG Barett. And sure enough they arrived a few days ago. In original Jaguar bags, labels, part numbers, the works.

The accessory belt p/n NCC7740BA and the supercharger belt NCA2211DA.

https://www.sngbarratt.com/uk/#!/Eng...f-e7b58166d952

https://www.sngbarratt.com/uk/#!/Eng...b-b13503975800

The accessory belt was fine.

However, the super charger belt was distinctly different from the one that I had fitted some years ago. This belt was much thicker, but more importantly it was ribbed on both side. The new one was ribbed only on one side. The way the superchargers belt is fitted means both sides do go across pulleys that are ribbed.


Here you see the old one, ribbed on both side and the new one, all flat on the “outside, only ribbed on the inside



Here you can (hopefully) see how much thicker the old double ribbed belt is compared to the new one


One more time the old belt



As far as I can tell, the part numbers are correct. The super charger belt fits and the wear indicator shows a new belt has been fitted.

Still, it seems a bit odd to have ribbed pulleys . The accessory belt is also only ribbed on one side. But the flat side runs over non-ribbed pulleys. So that makes sense.

Anybody knows what is going on here? Has Jaguar made some changes to the belts over the years?

Jeroen

 

The type of SC belt follows the type of pulleys used. There were at least two SC pulley combinations: 1. tensioner ribbed, idler smooth; 2. tensioner smooth, idler ribbed; (and maybe also both ribbed). If you have the pulley combination 1., you should use one side ribbed belt; the pulley combination 2. requires double ribbed belt. You can get the double ribbed belt on Ebay, Dayco 8DPK1327 (Dayco 6080522), 1327 mm. The SC belt on X350 engines is double ribbed (Jaguar C2C37055, 1355 mm.) but this belt is a bit too long for the X308.

It looks like Jaguar experimented with the pulleys (ribbed and smooth) in order to eliminate the belt squeak. My 1999 SC engine (Daimler Super V8) has the pulley combination 2. so I use the double ribbed belt.

 

 

Thanks M. Stojanovic and Bob,

So where do you go when you get confused about Jaguar. Well, I thought I would phone Jaguar. To add to the confusion for some reason my car (based on VIN) shows incorrectly in their database as a normally aspirated engine.

But even after having sorted that, they could only find the incorrect belt. So I thought back to SNG Barratt. After a bit of checking they came up with the correct one:

But that one is too long as mentioned. Tomorrow I am attending a technical workshop at an independent Jaguar specialist. I called him and he immediately knew all the problems and claims he has the correct belt.

So for now, I have put the old belt back on and hopefully tomorrow I am getting the correct belt.

One more thing, on my XJR the idler pulley is ribbed but the pulley on the tensioner is not. Is this correct?

I’m getting very good at replacing the Supercharger belt. I can do it in under ten minutes now!

What is a bit surprising that both Jaguar the Netherlands and SNG Barratt initially only came up with the old one, and not the more recent one. Recent being a relative term here. Because I have had these belts for at least 7-8 years as far as I can recall.


Jerone

 

Yes, your pulley combination is correct, same as on my engine (later arrangement), and it needs a double ribbed belt 1327 mm long (8DPK1327). For my engine, I recently bought a DAYCO 6080522 (8DPK1327) on Ebay for $49 plus shipping.

The Jaguar parts catalogue does not show this particular pulley combination nor the belt required for it so Barratt, and probably other parts suppliers, will not show them either as they normally just follow the parts catalogue.

 

Thanks again. I found the DAYCO belt on Ebay.co.uk. Ordered it two weeks ago and it arrived yesterday here in the Netherlands. Just installed it and it is perfect!. The tensioner is in the exact correct position for a spanking brand new belt!

I have spoken to a couple of Jaguar dealers and specialist. everybody keeps coming up with the same belt for the X350 as for the X308. Remarkably there is even some difference in length between the different brands of belts as well. Still, very happy I finally got the correct one!

Thanks everybody for the support and suggestions

Jeroen

 

Jeroen, I believe that the original supercharger belt on early V8 motors was single sided with a plain idler. Part way through the model run Jaguar changed the idler to ribbed and the belt to double sided BUT still 1327 in length. Now Jaguar Australia will only supply the belt used on later motors (1355) and require the purchase also of a stand off bracket for the idler to compensate for the longer belt. Something many of us down under are quite annoyed about.
Hope this helps