Squeaky serpentine belt. Solved!

[Kevlar7r]

I've been chasing squeaking belts on both motors since I got the boat. I think I finally solved it.

It appears that I was over tightening the belts. With the cheap stamped steel brackets for water pump, alternator, and power steering pump, the belt was actually flexing them in, causing the pulleys to be at an angle. This was causing the edge of the belt to rub against the edge of the pulley and squeak.

Haven't had it out and under load yet, but with the belt looser, both engines are running quiet.

I had searched many forums, and never saw anyone mention overtightened belts as a possible cause of squeak, so I'd thought I'd post it, in case anyone else is searching.

[HavaMax]

I have found that serpentine belts do not need to be as tight as a regular v-belt. Better design and I think better running surface.

[Phillbo]

Buy having them too tight you were also wearing out bearings faster.

[mmwjr]

My 97' had a bent raw water pump (B2) when I got it, this resulted in a misalign and belt wear.

Good for you and hope all else is fine

[oneradride]

Don’t the serpentine set ups have an idler and tensioner pulley…. I.E. no tightening required??

[HavaMax]

Not a gm based spring tensioner....

[mmwjr]

My 5.7LX is not spring loaded, the tensioner has a star gear that rides in teeth on the pully bracket. A socket is used the set the tension and then you tighten a nut to lock it.

[HavaMax]

The tensioner that mmwjr is talking about, it is very easy to over tighten.

[Kevlar7r]

No, like Mike said, it is a manual tension adjustment.



All the vehicles with serpentine belts I've had were spring tensioned, so I guess I've never really dealt with serpentine belt tension before. With v belts, well, if they squeak, tighten them. It appears that logic doesn't apply here.



When I first started messing with them, I remember thinking, why did they make the shaft so small (5/16's)? How are you going to put a big enough wrench on that?



Well it appears that one finger of force on the little wrench is all you need!

Taking the boat out tomorrow to go downtown for the new years fireworks and party at the Jacksonville Landing. Will find out then if I've solved the belt squeak, and starboard power loss.

[shrew]

My 8.1 has a spring tensioned serpentine belt. I admit, it makes changing the belt extremely easy. I would assume there are torque specs for tensioning the belt, are there not?

[Kevlar7r]

Probably. But, I've got a well calibrated arm. :-) I have a bad habit of not using torque specs... Unless I am inside an engine.

My neighbor came over the other day with a bolt with the aluminum threads wrapped around it. The were installing cam journals, and set the torque wrench to 13 foot pounds instead of 13 inch pounds. Oops!

[mmwjr]

They are two different wrenches, a foot pound wrench does not go down to that low of inch pounds.

Are they able to install an insert in the thread hole?

[Kevlar7r]

Thanks mike, I know that, I was shortening the story. Point is, they over torqued it. There are options, over drill and retap to larger, helicoil, or jb weld. Don't know which one they went with.