5.0 idler pulley - smooth vs. ribbed

[Hartman]

Guys,

The main idler pulley on my engine, the one at the top, was shot. This pulley was ribbed. So I went to the parts store and got a replacement, which happens to be a smooth pulley. The pulley works fine and the belt stays in place, but now I have a belt chirp. It will go away for a few seconds if I spray the belt with carb cleaner. The belt itself shows no signs of wear at all and looks fairly new.

I'm trying to decide if the source of the chirp is the belt itself or the smooth idler pulley that I got from the parts store?

 

[firepop5]

The top idler pulley on my 96 5.0 makes contact with the outer side of the belt, so it is a smooth pulley. The lower idler is groved and makes contact with the inner side of the belt. Does your car have A/C? Are you sure the new belt is routed correctly? Sometimes another belt will do the trick. Are you positive the squeak is coming from the belt?

 

[gavin]

the replacement should be a ribbed pulley.
I remember going through that... the one I originally got was smooth, but then exchange it for the ribbed.

the engine has 2 idler pulleys; 1 smooth and 1 ribbed.

 

[Hartman]

Nevermind, the stock pulley is smooth but the sides flare upward. The replacement is a regular smooth pulley. The new one looks smaller in diameter but it's hard to tell.

Today I purchased the smaller ribbed pulley and I'll be ordering a new belt.

 

[joebroni99]

Did anybody get this resolved? I bought the new idler pulley and it squeaks pretty bad for being new. Did anybody experience this? What is the solution? I put a new pulley and a new belt with the same issue.

 

[koda2000]

smooth pulleys run on the back of the belt. ribbed pulleys run on the ribbed side of the belt. the pulley the OP is talking about should be a smooth metal pulley.