Weird squealing

[woodwright]

I've got a 93 suburban with a TB 350 and 700r4 that I use for work. For the last few months its been slowly been developing a squeal. I just assumed it was an idler or something, and I just haven't wanted to deal with. But now I'm trying to get it ready to sell and need to fix it. I'm beginning to think its not an accessory though. It doesn't start squealing until I've been driving for about 20 minutes, and it only squeals at idle. when you put any load on the motor, it goes away. And it sounds like its coming from underneath near the rear of the motor. Any ideas?

 

[jekquistk5]

When is the last time you replaced your serpentine belt?

 

[woodwright]

I've had it for 2 years and never changed it. Wouldn't it squeal louder with more load on the engine?

 

[imiceman44]

I've got a 93 suburban with a TB 350 and 700r4 that I use for work. For the last few months its been slowly been developing a squeal. I just assumed it was an idler or something, and I just haven't wanted to deal with. But now I'm trying to get it ready to sell and need to fix it. I'm beginning to think its not an accessory though. It doesn't start squealing until I've been driving for about 20 minutes, and it only squeals at idle. when you put any load on the motor, it goes away. And it sounds like its coming from underneath near the rear of the motor. Any ideas?

Do you have a tin cover or aluminum cover on your transmission?

 

[woodwright]

plastic I think. If it was something rubbing, wouldn't it do it all the time?

 

[jekquistk5]

I've had it for 2 years and never changed it. Wouldn't it squeal louder with more load on the engine?

Not true, if its slipping over a idler because it looses grip. I replaced idlers twice on my dmax, then changed the belt. The belt did away with the squealing. And yes the squealing would go away when rpms went up.

 

[imiceman44]

plastic I think. If it was something rubbing, wouldn't it do it all the time?

On your transmission?
I don't think they ever made a plastic one.
Anyway if yu have an automatic, the flexplate at idle does a little wiggle but under power it smooths out, so if you have a tin cover and for some reason it got hit and bent closer, it could be touching when it wiggles.
The other thing I had once but it was in the front (you said towards the back) I had my engine mounts sagging so my balancer was rubbing on the crossmember when idling but apply power and it lifts up.
So look under the balancer to see if there is sign of rubbing.