Please replace it. I'm on my 3rd XK8 and I had belts go on 2 of them even though they looked good!

 

99 XJ8 VDP
Old belt is cracked and 14 years old. Only have 72K miles on the car but figured it would be good to replace the belt before it breaks on its own.

Taking off the old one was no problem at all, 15mm socket on a long breakerbar, turn all the way left toward airbox untill it goes no further and old belt easily slides off.

I routed the new belt as per Gus' diagram, except for the final pulley on the alternator, since the JTIS said to start removing from there.

I verified I have the correct Goodyear Gatorback replacement belt (GTR-4070915), it even has the diagram on the carton, the words "Jaguar XJ8 4L" plus the number on the carton matches the number on the belt itself. (so I know nothing got switched somewhere).

However, I am unable to get the new belt on. I realize a new belt is going to be tighter than the old belt, but still.... Tried everything I know (short of using some kind of lube; figured that would not be such a good idea).
I futzed around for an hour and gave up.
Put the old belt back on without a problem and everything is back to what it was when I woke up today.

Anyone know what I am doing wrong??? It can't be that hard.....

 

Does the new belt match the old belt in size? I am attaching a link for installing the belt go to page 121.

Link http://www.jagrepair.com/images/Auto...sb_09_2003.pdf

Hope this helps.

 

Thanks, Gus. That did cross my mind before trying the new one on so I laid them on top of each other before (trying to) mount the new one... They were indeed the same length, or certainly not off by much. I compared the part number on the belt with the number on the package and they were the same... I even (after my debacle last weekend) searched and verified that indeed GTR-4070915 is for the 99 Jaguar XJ. Sigh....
I think I might start a new thread on this issue since I kinda highjacked this one!

 

Old post ... but in the intervening time Sean B has posted the standard part numbers for the bearings. A complete set of four bearings to replace all bearings in the two idlers and two tensioners on a supercharged model costs under $20. The naturally aspirated models only require 2 bearings.

 

What a coincidence, ExportGuy!
I have the exact same belt (took a pic below ). I actually had Coventry Cars mechanics trying to get it on, and even they failed!!! It surely isn't your fault if Coventry cars mechanics in San Diego can't do it either!!! They offered OEM Jaguar belt for >$100 which I clearly refuted .
I have Gates K070916 currently sitting on my table. Hope the "16" in the P/N will make a difference. I will report back tomorrow during the day (PST ) on the progress.
BOTTOM LINE, GOOD YEAR GATORBACK AS PICTURED BELOW DOES NOT FIT 1999 4.0 ENGINE!!! Quite puzzling...

 

OMG...
If that's it, that's incredible! I can't understand how Goodyear can claim their 070915 will fit when it clearly doesn't.
I've never actually changed an accessory belt myself, so I thought it was something I was doing wrong, or at least not right.
If this is the fix, I'll be a very happy guy!
Thanks, Danny!!

 

I am back with good news, ExportGuy! The Gates fits perfectly! I also happened to be replacing it on my own for the first time btw . I borrowed a kit from local Autozone, but all you really need is a good, longer breaker bar with 15mm socket...preferably deep socket.
Once I compared the GY Gatorback and Gates it was quite obvious that fitting the former would be impossible due to the deficiency in length. One could humor me why Good Year uses the Jaguar 4.0L designation with the very exact belt-pulley routing on the retail sleeve ...

Below is couple pics with the GATES K070916 installed and a little Photoshop fun .

Please, let us know once you are done replacing yours!
Best,
Danny.

 

Wow. I think I'm going to contact Goodyear, see how far I get with this. I don't even remember where I got the GY belt, I've had it for about 6 months in my trunk. But that doesn't matter, because all vendors just use the GY info that says their belt will fit. While indeed it doesn't.

I'll let you know when I've rep[laced my belt and what kind of response, if any, I get from Goodyear....

Richard

 

There are a couple of interesting points here. The numbers on belts are codes for what the measurements and properties of the belt are.

These 4.0 liter engines changed the length of belt they used in 2000.

The Gatorback 4070915 indicates that it is a 7 groove belt (number 7 in stock number) and that the length is 91.5" long. For my 2002 it specifies that a Gatorback 4070923 is needed. Thus it is 92.3" long 1.1 inches longer.

The Gates K070916 by this nomenclature would be 91.6" compared to the Gatorback 4070915 at 91.5 inches thus a 0.1" difference. It's curious as to why that Gatorback was too short.

I am getting ready to change my belt today with a Gatorback 4070923 (2000 cars and forward). Why the Gatorback? It came as a spare (and new) in the trunk of another XJ8 I bought.

I am getting a chirping on start-up. A very, very small amount of Armor All sprayed on the belt stops the chirping. I will probably repack the bearings on both the load and static tensioner pulleys. It will be interesting to see if this stops the chirp.

Final note, I have had other cars where the belt would sometimes chirp. Holding a fine file to the belt's edge while the car was running would clean up the edges that tend to fray or flatten as time goes by. I tried this on my current situation and it did not abate the chirp.

 

Never heard of filing a belt before. Interesting concept, but be careful down there....

 

Just drove 3000miles in my 2000 xk8, Maine to Parris Island SC to Birmingham AL and back to Maine. I found myself thinking of your mantra "life's too short to drive a Prius"!!!

 

This was VERY, VERY helpful.

I did change the belt but did a couple of other things too. I did replace the idler pulley as it was 20 dollars AND the replacement was of a different design.

The original has a lip that it towards the front of the car which, I assume, keeps the belt from jumping off the front of the pulley (tho I don't know why/how it could). The new one does not have that lip. The original one was polished to bare metal at the 90 angle where the flat part of the pulley meets the vertical lip. That indicated to me that there was major rubbing at that point. I do believe that is where the chirping was coming from.

I repacked the bearings in the tensioner pulley. That was great as there was not a replacement that I could find at the aftermarket stores.

The Gatorback went on easily without any problems with length. The long handled socket breaker bar and socket can be a bit difficult to work with. Specifically, if the socket cannot be inserted on the breaker bar in the right way there is not enough "reach" to pull the tensioner against its spring load. Fortunately for me, the bolt holding the tensioner pulley tightened and stopped at just the right position to allow my breaker bar to swing from 10 to 2 o'clock without a problem. I can see how this could be an issue.

The Gatorback belt does had a screened area that says "Official Belt of NASCAR." I might have to get some lacquer thinner and rub that out.

 

Don't worry. It will only stop where it is readable when you are trying to show off the motor to a buddy. All other times it will be on the bottom of its travel.

 

And what was VERY helpful is the fine folks at Goodyear put a diagram of how to run the belt on the back of my package too: