tensioner/serpentine belt sizes?

[Keseleth]

Hey all,

What length serpentine belt and diameter belt tensioner would I need for my 03' Renegade 3.7L?

This has been driving me crazy, so I hope somebody can help. My KJ died Thanksgiving morning, and I discovered that the tensioner had seized up, threw its' outer ring, and mangled the belt. Replacements seem to come in several sizes for each part, and I can't find the info anywhere on which I need. As my belt is stretched and mangled, and my tensioner decapitated, I can't just measure them to find out, either.

Any help would be much appreciated! Thanks!

~Kes

 

[JeepJeepster]

When I replaced the tensioner on my kj the replacement was larger. Fits fine. Ive got a thread around here somewhere with pics. Got the stock size belt.

 

[Keseleth]

When I replaced the tensioner on my kj the replacement was larger. Fits fine. Ive got a thread around here somewhere with pics. Got the stock size belt.

Thanks, JeepJeepster! What size is the stock size, though? Or how would I find out? None of the 'OEM' listings I've seen give a size, and all the others (OReilly's, Autozone, etc) give at least two sizes.

 

[dude1116]

I just remember Pepboys gave me one size for the Chrysler 3.7L. I believe any number around 87" (+ or - .5 inch should do.).

 

[Keseleth]

Thanks, dude1116! It's all fixed now. We were able to salvage enough of the shredded belt to make out the stock number, and from there determined which tensioner was needed.

For anyone else with a similar issue, here is my engine and which parts I needed:
3.7L V6, on a 2003 Renegade:
-3.5" tensioner assembly
-87.25" serpentine belt

Thanks, all!

 

[LetFreedomRing]

On a side note, I just went through the same thing trying to find out the belt sizes to pulley sizes.

What I found out is:
- If you have the smaller tensioner (pulleys are the same size, 3 inches)
- You will need the shorter belt. It measures 86 3/8 inches

- If you have the larger tensioner (pulleys are different sizes, I believe
one is 3 inch and the other is 3.5 inches.)
- You will need the longer belt. It measures 87 1/4 inches.

No matter what version of tensioner you have, either one will work as long as you get the correct belt length. I have read the the "new and improved" tensioner is the one with the same size pulleys. My old tensioner had the different size pulleys, I ended up putting one on with the same size pulleys with a shorter belt. Everything works perfectly.

 

[k99jk99j]

Does anyone know what the reasoning is behind switching from 3.0inch to 3.5inch pulleys, in the middle of the production run?
They both seem to accomplish the same thing with the right belt?