I need to replace the supercharger idler pulley on my 99 xjr part number NCC7753AD. I am looking for a part I can find locally and there are no Jag dealers here. Does anyone know of an equivalent part that I might be able to source from a chain parts store. Possibly Gates 38028?

 

SC idler pulley under number NCC7753AD appears to be NLA. Also, this pulley was grooved on some engines and smooth on other.




If only the bearing is bad, just buy SKF 6303-2RSH/C3 or equivalent (like *** 6303.2RSR.C3) and replace it.

 

Check this thread out too https://www.jaguarforums.com/forum/x...acement-65171/

The bearing is the way to go, if possible. Pretty easy to do, especially if the idler has a landing "lip" like on the lower photo, you can just press the bearing in until it rests on that.
On a 99, you'll probably have the smooth surface idler. You could replace it with a ribbed idler, you'd just need to replace the SC belt with a double-ribbed one to match.

It's been a while, but I think the pulleys don't interchange between the SC idler and acc idler. (think the SC idler is larger diameter?) According to my notes though, the acc idler and acc tensioner pulleys do interchange, with most brands anyway, just gotta use the correct bolts and orientation.

 

My 1999 Daimler Super V8 has a grooved SC idler pulley and a smooth SC tensioner pulley, using a double-ribbed belt. The pulley diameters I measured are as follows (the grooved pulley diameter measured over the peaks of the grooves):
SC Idl Grooved 88 mm 47 mm OD bearing (SKF 6303-2RSH/C3)
SC Tens Smooth 76 mm 40 mm OD bearing (*** 6203.2RSR)
Acc Idl Smooth 76 mm 40 mm OD bearing (*** 6203.2RSR)
Acc Tens Smooth 76 mm 40 mm OD bearing (*** 6203.2RSR)
The correct double-ribbed belt for this pulley setup is Dayco 8DPK1327 (Dayco 6080522) 52.244 in, (1327.00 mm) long.

It seems that earlier models had different pulleys and, according to the info I found, their diameters are as follows (I do not know where exactly the shown diameters for the grooved and the flanged pulleys were measured):
SC Idl Smooth 90.7 x 38.0
SC Tens Grooved 83.3 x 38.3
Acc Idl Smooth Flanged 85.5 x 37.2
Acc Tens Smooth 77.0 x 37.2

 

I appreciate the help guys! I'm in a bit of a time crunch so I went with a used one from Jagbits. At some point I believe maybe in 2000 they switched the pulleys to a grooved pulley as stated above and the diameter changes so if you switch to the grooved you have to switch out all the others.

 

If you change the SC idler pulley from smooth to grooved, you only need to change the SC tensioner pulley from grooved to smooth. Other pulleys have nothing to do with it.

 

I did this a year ago and would recommend just replacing the bearing. Wayyy easier than trying to source something.

 

You shouldn't just install a used pulley, you should replace the bearing first as the one in it may already be on the way out. You can actually buy two bearings, for both pulleys, and have one spare.

 

After multiple supersessions, NCC7753AD is now C2D21157, and readily available through a Jaguar dealer.
If you have any issues obtaining a new one, message me.

 

C2D21157 is a ribbed pulley, NCC7753AD is smooth so they are not interchangeable.

 

As shown from the catalogue,
C2D21157 is the latest supersession from Jaguar.

 

Yes, smooth SC idler pulley was superseded by a ribbed one (C2D21157) but, at the same time, the SC tensioner pulley was superseded from a ribbed one to a smooth one. My late 1999 Daimler Super V8 has the superseded ribbed idler (like C2D21157 but steel, not plastic) and a smooth tensioner pulley (and a double sided grooved SC belt).

So, with the early smooth idler (like on the parts diagram posted above) you have this tensioner:


And with the later ribbed idler, you have this tensioner:


Jaguar's changes of the pulleys (metal, plastic, ribbed, smooth) and the lengths of belts, I think, is a bit of a nightmare.

 

Hi, I have a question, is the none ribbed in the photo fitted with the side shown facing the engine or the front of the car? The pulley has a lip that the bearing sits against and I am not sure which way to fit it.

 

It is as on the picture above. Fitted to the engine like on this picture:

 

That's brill, Thanks guys

 

Here is the Jaguar TSB explaining the belt change. It was to try and stop the belt from squeaking on cold start up. I had this done under warranty years ago on my 2005 STR. Changed the belt to ribbed on both sides and pulley changed too.
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