STRUGGLING getting this VelocityAP belt back on and over the pulley system with the new larger VAP lower crank pulley on (yes Im using the velocity AP belt they provided pic of the one they provided is the lower one in the pic and just slightly longer than OEM). Been at it for 2 hours and cant figure it out.

I found tutorials on here as well as YouTube and found two different ways described:

1. Put the belt over all pulleys and leave the tensioner pulley (#2 in pic) until last… the tensioner pulley is EXTREMELY challenging to move (seemed much easier to move the tensioner when i took the belt off).

2. Put the belt over all pulleys except for the idler pulley (#3 in pic) and then pull it over. Idk how you’d even go about this method but tried a few different ways and didn’t come close.

I also tried putting it over all pulleys except top supercharger pulley (#4 in pic) and standing in the engine bay trying to get leverage to wrap it around the supercharger pulley. Not even close

Any ideas? I don’t know why this tensioner pulley is nearly impossible to move more than like 1cm. Is that normal?

Also, the gap between the crank pulley and the pulley above it is TIGHT. I had to really push/wiggle the belt through the tiny gap to get it seated. Is that normal?

I’m at a standstill here on the install and don’t know what to do.







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Never done it myself but I am fairly sure the tensioner (#2 in your pic) should rotate/loosen a fair bit more than 1 cm, my guess is at least 2 or 3 cm anti-clockwise so it is pointing straight down or a little past straight down.
These tensioners are known to wear out and rattle so maybe yours is stuck/fubar?

 

@dbleoh7 I did this alone so it is bringing back fun memories!

The key here is the tensioner must be moved significantly more than 1 cm. With one hand I used an 18 inch breaker bar and pushed the end of the bar the opposite direction of the tensioner (counterclockwise as you face the engine or to the right of the car). It takes a bit of torque to overcome the tensioner. Practice a couple of times to figure out the ergonomics. (better yet get an assistant to do the bar while you do the belt). Then with your other hand slip the belt on. I believe I did this from underneath the car. I also remember the tight gap between the pulleys that you show. It all worked out though. Triple check that the belt is seated perfectly on all pulleys.

Check out the photos by @Bierry and the others' experiences here, especially about belt issues:

https://www.jaguarforums.com/forum/f...2/#post2595117

 

Yeah, see the square hole in the #2 tensioner arm? (and the other belts' tensioners)

That fits a 3/8th square drive from a ratchet or breaker bar, which provides enough leverage to move the tensioner a LOT more than 1 cm.

 

One more tip (from my own experience) - If you are using a breaker bar, be sure the breaker bar isn't contacting some of the structure around the front of the engine and artificially limiting your travel. On my first attempt at installing the belt with the VAP lower pulley, I was using a 1/2" breaker bar with an adapter to 3/8" to fit the tensioner. That combination caused my breaker bar to hit something and limit travel before the limit of the tensioner travel. I have since switched to a tensioner tool (https://amzn.to/3Ykt09w) which is much thinner and allows full travel and extra length for leverage.

 

The first time I replaced the belt was when I put the pulley on. I recall cataloging that as a 1/2 day job without a lift, and that I did wrestle with the belt a bit. I did the belt only later after some slippage in cold weather at the top of the rev range. Mine is apparently a transition VIN and JLR changed the cutover to a different size belt. The second time I did everything from above and I think it was about 20 minutes. Key to that was having a long enough lever to that 3/8" square hole in the tensioner. With the right leverage it moves easily several cm and makes the job easy. I can't remember if I used a breaker bar or a ratchet, but I have a selection of both on hand, so probably grabbed a handful. The tensioner tool in post #5 looks like a winner if your present selection of tools doesn't quite fit the bill.

 

I figured it out. Thank you everyone for the comments. I stepped away from it for a day to give my shoulders and brain a break/refresh and when I got back to it I almost immediately figured it out. I was pulling on the breaker bar attached to the tensioner when I should’ve been pushing upwards. I was using the blue torque vector when I should’ve been using the yellow torque vector. Once I figured that out I got the belt on within 15 minutes

 

Yeah, widdershins versus sunwise. We've all been there.

 

I'm going through the same issue, supercharger belt impossible to install, I have compressed the supercharger tensioner all the way and the belt does not want to slip over any pulley, any help? Don't understand what yellow vector you mean?

 

His description was that he was pulling on the breaker bar, parallel to the bar, rather than pushing on the bar from the side, perpendicular to the bar. However, if you have compressed the tensioner completely, that's not your issue.

Since I had all the splash shields off, and the car on a lift, I had easy access from below. What I ended up doing was routing the belt over all the pulleys, except the crank pulley. I fed the belt through the gap between the idler and crank pulley, but other wise left it loose. Then I compressed the tensioner while a helper wiggled the belt around the crank pulley. What you are really looking for is which pulley has the lowest lip on it, meaning you need the least amount of slack to get the belt on. But you have to combine that with the practicality of the belt routing. It's pretty much impossible to use the lower idler because of the tiny gap between it and the crank pulley. You also have to balance it with whether you are doing it solo or have help.

Also, double check the belt part number. Mistakes do happen and it's possible you got shipped the shorter belt -- this assume you only did the lower pulley and not both. If you did both, the shorter belt would be correct.