Bearing noise coming from Alternator/Tensioner area. Used Penetrating Oil and it's gone.

[Angry Possum]

A few days ago I had noticed a possibly spun bearing noise eminating from the alternator area in the Ranger. I'm not sure what's directly underneath the alternator, however I used penetrating oil on both areas, and the noise is gone. Does anyone know what is directly underneath the alternator, it's a part that's included in the belt pulley section, it's not the water pump, it's in between them both. Anyways the noise is gone for right now.

 

[Shran]

Idler pulley? Pretty cheap, if it's making noise, replace it... those bearings won't spin for long if they're dry & worn.

 

[Curious Hound]

I’m not familiar with layout on the front of a 4.0l. But your choices of pulley driven pieces are; alternator, A/C compressor, power steering pump. Fan clutch, tensioner pulley and probably an idler pulley. Crank shaft powers them all.

do NOT spray oil on the belt or pulleys. They rely on friction. So, oil will make the belt slip.

 

[Angry Possum]

Idler pulley? Pretty cheap, if it's making noise, replace it... those bearings won't spin for long if they're dry & worn.

Yeah, Methinks it's the Idler pulley bearings or the actual alternator bearings. I appreciate the input. I'll keep it monitored and to be proactive, I'll just go ahead and order the idler pulley on Rock Auto. There probably cheap enough anyways. It's good to have on hand regardless

 

[RonD]

Facing the front of the 4.0l OHV engine the tensioner pulley is below the Alternator and the idler pulley is to the right of alternator

 

[Angry Possum]

Question- Would I just order the whole belt tensioner unit or the individual bearing pulleys. They sell them separately. Maybe I'll just get both the idler pulley and the tensioner pulley.

 

[Angry Possum]

I’m not familiar with layout on the front of a 4.0l. But your choices of pulley driven pieces are; alternator, A/C compressor, power steering pump. Fan clutch, tensioner pulley and probably an idler pulley. Crank shaft powers them all.

do NOT spray oil on the belt or pulleys. They rely on friction. So, oil will make the belt slip.

Thanks, yeah I dropped some oil on the shafts actually closest to the housing of both alternator and tensioner, I didn't get any oil on the actual belt. I'll see how it works out.

 

[Angry Possum]

So far so good, no more noise. Good ole 3 in 1 Oil.

 

[Curious Hound]

Question- Would I just order the whole belt tensioner unit or the individual bearing pulleys. They sell them separately. Maybe I'll just get both the idler pulley and the tensioner pulley.

View attachment 101669

I geenrally order the idler pulley and the tensioner pulley. If you are in a rust belt area, it might be wise to order the entire tensioner assembly so that you know there isn't any binding preventing it from properly tensioning the belt.