Belt tensioner

[HunterK]

Hey guys, I'm in the middle of replacing the whole cooling system on my 89 Comanche while putting a new surpentine belt on my tensioner broke. The horizontal bolt that is used to tighten it up or loosen it, free spins now. I've looked around and can't find anywhere that sells a tensioner assembly. Anyone have any idea on where I can order one. Thanks.

[Minuit]

Can you get one from a junkyard?

[DirtyComanche]

I'm thinking it would pretty much be junkyard only.  If there isn't any local yards, I'm sure one of them will pull it and ship it to you (for a price....).

[88mjblue]

Jon (aka 5-90) was working on a prototype replacement for this very part, but not sure he has it made up yet. The whole power steering assembly has to come out to change this, so I would find one from a junkyard and swap it out.

 

 

Here's an excerpt from his website:

 

On the earlier XJ/MJ with 4.0, the belt is tensioned by a long bolt underneath the power steering pump. OK so far.

This bolt has a knuckle on it - this knuckle has two holes. One is threaded to be borne by the bolt, the other is smooth and has a stud on the bottom of the pump housing on it. Still fine.

When you tighten the belt, all of the strain is borne upon the threads in this knuckle - about a half-inch of threads about 1/18" deep. Small problem.

This knuckle is made of "sintered" metal - metal that started life as a powder, was poured into a die, and heated and pressed to make a solid part. Problem!

While sintering (now called "powder metallurgy") has made remarkable advances in strength, these knuckles were made before the advances. I've broken three of them so far. Considering the entire power steering pump has to be removed to replace the thing, we think it's worthwhile to make something that won't have to be replaced so much...

 

Again, these parts are CNC machined from wrought bar stock, and the solid threads will hold up nicely to the strain of holding belt tension before you can torque down the rest of the pump bolts.

 

[HOrnbrod]

^^  This. If in fact the adjusting collar is broken, they are readily available. I had to replace mine recently. This is what happens when they break:

 

 

This is what you need:

 

 

Available HERE and many other places. Part number 53002915.

[Minuit]

Curious since my belt adjuster is a little wonky but not broken yet - will switching to the new style power steering pump get rid of this adjuster?

[HOrnbrod]

Curious since my belt adjuster is a little wonky but not broken yet - will switching to the new style power steering pump get rid of this adjuster?

 

No. Even though the adjusting braketry is completely different, they both use this same collar. Even the long adjusting bolt is the same.

[HunterK]

^^  This. If in fact the adjusting collar is broken, they are readily available. I had to replace mine recently. This is what happens when they break:

 

 

This is what you need:

 

 

Available HERE and many other places. Part number 53002915.

that's exactly what broke on mine, a friend of mine who has a local jeep shop has a pile of them laying around.

[HOrnbrod]

that's exactly what broke on mine, a friend of mine who has a local jeep shop has a pile of them laying around.

Grab a spare or two, because it will break again, especially if they are used.

[EvilMJ]

HOrnbrod, thank you VERY much for posting this fix.  I broke mine several months ago and just tensioned it as best I could until I found a fix...  This is my fix!