Replacement Serpentine Belt So Tight Topic is solved

wanderdüne · Post by **wanderdüne** » 26 Jun 2021, 19:03

Hi, I just changed out the tensioner (INA) and tried to change out the belt (Continental 6DPK 1825) on my 2006 XC90 2.5T. There was a split on this at chassis # 288075, with before the split getting an 1841mm belt and an 1825mm belt after the split. My chassis is 3xxxxx. so I chose the after the split parts.
I verified the split in VIDA and some parts sites.

Anyway, I got the old belt off and removed and installed the new tensioner, but try as I might, the new belt won't install. I bottomed out the tensioner and till have about a third of the PS pulley that I can't get the belt on to. After several attempts, I reinstalled the old belt which wasn't bad, just wanted a new one for a road trip.

For the life of me, if the 1825mm is indeed the correct belt, I have no idea how to get it on. Now the old belt didn't have a lot of excess either, but it did go on. I tried to get a measure of the two belts before I reinstalled the old one, but I can't tell if they are within 16mm of each other.

In your experience, are these belts just super close when new? I've only done this on a Mercedes, and there was a good amount of play for fitment on that one. I think I'd literally have to shoehorn this one, and likely would damage a pulley in the process. I'm wondering if I should order the 1841mm at this point.

Any thoughts? Thanks

Post by **SuperHerman** » 26 Jun 2021, 21:08

Compare parts. Tensioner and pulley size and belt size. Visually match up the belts and compare their lengths. If you want to go wild, count the teeth of the old belt and compare the number to what the new belt has.

If the old belt fit - then exclude all new parts and then the belt.

wanderdüne · Post by **wanderdüne** » 26 Jun 2021, 22:18

I did measure the pulley and it's the same. I tried to measure the belts against each other by looping one end on a bar in my vise and pulling them straight next to each other, but couldn't really see a difference. Short of cutting them and laying them flat, I don't think I'm going to be able to do anything definitive. Thanks

Post by **cn90** » 26 Jun 2021, 22:49

- The way to measure belt is to have a second person to help hold the other end.
Otherwise, put both of them on a straight pole (drive a straight rebar into the grass as a pole) and pull/measure.

- My 2005 XC90 2.5T uses the longer serp belt.

- I think different belt lengths come from different PS Pump Pulley diameters.

- Yes, get the longer belt and see what happens...

https://www.swedespeed.com/threads/serp ... on.627541/

wanderdüne · Post by **wanderdüne** » 26 Jun 2021, 23:45

Thanks, the link is really helpful. The Conti belt had absolutely no stretch to it, but I think it is the wrong size anyway. Maybe mine had the PS pulley or pump replaced, who knows?. I'm going to pick up a Gates DK060725 in the morning locally. I think it's an 1843mm, so 2mm longer than stock for the longer belt. Hope it works, I was losing my mind over the other one. I'll post up what I find out.

Post by **RickHaleParker** » 27 Jun 2021, 00:52

Gates DK060725 is 72.54 inch ( 1842.5 millimeter ) you have the right size belt.

When the belt is off center the Circumference shrinks. That why the belt is so hard to get on. Friction makes it even harder to get over the edge. Have you tried a film of dish soap. So the belt will slide over the edge instead of dragging ?

wanderdüne · Post by **wanderdüne** » 27 Jun 2021, 08:32

RickHaleParker wrote: ↑27 Jun 2021, 00:52 Gates DK060725 is 72.54 inch ( 1842.5 millimeter ) you have the right size belt.

When the belt is off center the Circumference shrinks. That why the belt is so hard to get on. Friction makes it even harder to get over the edge. Have you tried a film of dish soap. So the belt will slide over the edge instead of dragging ?

Thanks, I know I have the right belt for my chassis#, the 1825mm belt, but there is no way short of levering that this belt would be able to go on. Actually the old belt was even difficult to get off. I don't know if the old belt is the 1825 as there is not remaining identification on it. Even with the tensioner pulled to full lock, it's just clear to me that the belt is too short. The older spec belt is only 16-17mm longer, and I'm hoping that it will work. I've only changed out one serpentine belt before, in a Mercedes 300E, and besides the easy access, I don't recall having anywhere near this level difficulty pulling the belt on.

Post by **cn90** » 27 Jun 2021, 10:38

Measuring belt length is not difficult.

See this link:

https://www.thepoultrysite.com/news/201 ... ing-vbelts

PS: Always keep the OLD belt in the trunk as spare, old-schooled method, but it is free, why not?

Post by **SuperHerman** » 27 Jun 2021, 13:29

If in doubt count the teeth. Take a marker, crayon, piece of tape as your zero mark and start counting. New belt should have a mark you can start at.

It is that simple. No guessing and ordering another incorrect part. If the teeth count is the same you have a problem elsewhere, something is installed wrong, routing wrong or you are doing it incorrectly.

Post by **RickHaleParker** » 27 Jun 2021, 14:14

wanderdüne wrote: ↑27 Jun 2021, 08:32 I don't recall having anywhere near this level difficulty pulling the belt on.

Keep in mind the old belt has been stretched. When it was new it was just as hard to get on.

WARNING: Do this wrong and somebody can get hurt. Proceed at your own risk.

Disable the engine so it cannot start. Pull all the coil pack wiring or injector wiring ..ect.

One trick is to wedge something between the belt and pulley like you are trying to pry it on. Such as the tip of a flat screw driver, It need to be thin. Then have somebody bump the starter. The rotational force will slip the belt over the edge of the pulley.

This takes two people that understand what they are doing. The person doing the wedging need to be able to anticipate what is going to happen so they don't get a finger crushed or something poked by the pry lever. The person operating the starter need to understand the difference between a bumping the starter and cranking the starter. Practice before doing with the other at risk.

It can be done by one person only with a remote starter switch.

I'm not saying anymore. Either you can visualize the spatial relations or you cannot.