Can't get serpentine belt back on

[platon20]

I took off the belt to service the impeller pump a few days ago when it was 70 degrees out.

Now that the temp has dropped to the 50s, I cant get it back on.

I checked the belt diagram multiple times so I know I'm putting on the right way.

The idle/tension pulley is way too tight.

So I think there are a couple of options:

1. Try to heat the belt up before putting it back on. Should I use a tub of hot water? Blow dryer? Butane torch?

2. Try to adjust the tension of the idle/tension pulley so that it will move further out of the way so it's easier to get the belt back on. However I don't know how to do this or if it's even possible. I showed pictures of the tension pulley below. Is there a way to adjust it so that it rotates further and provides less tension so I can get it back on?

 

[Bt Doctur]

There is no need to remove any pully to replace a belt. If you have the correct size belt it goes on with no issues.

I checked the belt diagram multiple times so I know I'm putting on the right way.

serpentine belt diagram ,mercruiser at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

Check it again

 

[Lou C]

Usually you put a 3/8ths ratchet square end in the square fitting in the tensioner and use that to move the tensioner in the right direction so you can install the belt.

 

[alldodge]

Your probably not feeding it in the correct orientation. What motor is this?

 

[platon20]

It's a 6.2L Mercruiser MPI 300HP on a 2017 Chaparral 246 SSI

I didn't remove the pulley to put the belt on, I removed it so I could get access to the impeller pump which is directly underneath/behind it. There's no way for me to remove the impeller without taking out the tensioner/idle pulley.

I searched a lot of youtube videos but those videos all show a different kind of pulley tensioner. Mine is different than the other mercruiser videos.

The pulley has 2 positions -- "tight" and "relaxed"

The default position is tight. I have to use a ratchet to move the bolt clockwise on the tensioner, which causes the pulley to move down to get it into the "relaxed" position. And while I hold pressure on that ratchet, I have to get the belt back on the pulley.

The problem is that even in the "relaxed" position the belt is too tight and won't go on the pulley no matter how much force I put on it. It's the same belt that I took off so it's not a new belt so I don't understand why it doesn't fit all of a sudden. The only thing I can think of is that the cold temperature has caused the belt to shrink.

I will try to post a video later.

 

[alldodge]

Does this look like the arrangement?

 

[alldodge]

Found a better pic

 

[GA_Boater]

If it came off, it will go back on. Any unlikely shrinkage due to cold will be taken care of by the tensioner. A used belt would stretch some over time and old or new, not shrink from temperature changes.

How hard was it getting the belt off? It should have almost fallen off. And as this has been mentioned by others, is the belt routing correct?

 

[platon20]

Yes that diagram is correct.

It takes quite a bit of torque to get the tension pulley into the "relaxed" position, but once it does, the belt fell off easily and I didn't have to pry it off.

 

[Bt Doctur]

try putting it on the alt pully
relax the tensioner and slip it on the alt pully.

 

[bbook83]

Is there any chance that the seawater pump was re-installed improperly, causing the pulley on that pump to be mis-aligned?

 

[platon20]

Update:

I got it back on but nearly broke my wrist doing it.

I was trying to use a 3/8 inch ratchet wrench that's only 12 inches long which wasn't enough to give me leverage to rotate the tension pulley all the way down.

So I went to home depot and bought a much longer 24 inch long breaker bar which allowed me to rotate the pulley another quarter inch and that was finally enough to get the belt back on.

If you're getting the belt off, you don't have to rotate it as far compared to getting the belt back on.

 

[Lou C]

It’s all in the leverage lol! Glad you got it!