Is there too much play in this A/C drive belt idler pulley?

[MaddieCycle]

Have an intermittent belt squeal on compressor start.  Can't get it to reproduce when home. Tends to only happen when very hot out. Have not been able to reproduce while actually under the truck.  Thought I have the belt tight enough.  Trying to isolate other causes before I clamp the belt tighter. Don't want to kill the bearings.

Compressor spins easily and quietly by hand. Not sure that means anything. Idler also spins quietly and freely.  Is there too much lateral play in the idler bearing? Maybe just worth replacing it and see if the problem starts? Hope it is not the compressor.

 

Here's the video: https://drive.google.com/file/d/11-GGslhRxkGGE66tOeoHBvEntrA-nUnf/view?usp=sharing

[datzenmike]

Push on the belt half way between the pulleys with your thumb. 22 pounds should deflect about 1/3" for air conditioner. 1/2" for power steering and water pump.

[MaddieCycle]

Yeah it seems properly tight to me, but maybe a little more slack than when I put the new belt on a few months ago.  I'll tighten it up a taste and see if I can get it to squeal again.

[datzenmike]

New belts will stretch. Loose is probably better than too tight.

[MaddieCycle]

I think the main question is whether the play in that bearing is enough to indicate that the pulley is the source of the problem, assuming I have the tension correct.

[datzenmike]

Drive till it gets worse, fails or nothing happens.

[Stinky]

Your squeal is caused by the belt slipping, or not...If that is what what you know.  Then, why?  Could it be that the compressor is to hard to turn?  If it is taking normal pressure to turn, then your belt is to loose. 

 

That is to much play....I doubt that it would cause it to slip.  I really doubt that it would cause it to slip.  And not sure that it is worth worrying about....but maybe, a wobble is tightening and loosening your belt.  The worst thing that could happen is that it could eventually come apart and fly through ur radiator   : )   : )  : )    

 

Those pulleys are available.  Go to rockauto and dig.  Then cross-reference  at your favorite store (Autozone, Napa, etc.)  those pulleys are fairly generic.  I replaced mine, but I don't remember with what.  It was hard to find.  But, w/the PN you should be able to find it in your area.

 

https://www.rockauto.com/en/catalog/nissan,1986,720+pickup,2.4l+l4,1210385,belt+drive,idler+pulley,6956

Edited June 17, 2021 by Stinky

[NC85ST]

You don’t even have to replace the pulley. Just replace the bearing.

[datzenmike]

On 6/12/2021 at 9:22 PM, MaddieCycle said:

 

Compressor spins easily and quietly by hand. Not sure that means anything. 

 

Compressor's clutch is likely free wheeling.

 

 Truck will run without the air conditioner so drive it till it fails or doesn't.

[Stinky]

That doesn't mean anything.  Unless the clutch is engaged, the pulley just freewheels.

 

If you want to replace just the bearing, then you'll need the PN off the old bearing....it will be written in the rubber.

 

[MaddieCycle]

Thanks for the Rock Auto p/n, off to the parts store now.

 

When I spun the compressor pulley the clutch was not engaged because the truck was off.   The pulley itself seems fine.  Not sure what that says about the compressor innards.  Probably not worth trying to turn it while the clutch is engaged because I probably couldn't turn it by hand.

 

I'll try a new pulley with what seems like proper tension. If that is a no-fix, I am assuming the only other thing to do is change out the compressor.  A/C is important to me.

[bottomwatcher]

I am amazed your AC works usually one of the first thing to go on these old trucks. Don't jump to compressor replacement just yet these old systems become a can of worms real quick. Compressor leads to refrigerant conversion with incompatible oils and "O" rings. Dryers, thermal expansion valves, condensers, evaporator the list goes on. I want AC back on my truck at some point but the only way to do it correctly is all new parts and isn't cheap. Someone did a real good write up on here with all the necessary parts or you could go the Vintage air route. It seems once you crack these old systems up it becomes a cascade of hard to find parts. Good luck on solving this issue. I would exhaust all other options first.

[datzenmike]

Ocam's razor.The simplest solution is usually the correct one. Belt slips and squeals when the compressor load is suddenly applied. Tighten or replace the belt. Additionally you might try applying some spray belt dressing.

[Charlie69]

I quit buying Gates belts as they all seemed old and hard and squeeled like crazy.  Just bought a $7 alternator belt from O'rielleys and it works fine. I have a spare in the truck.

Edited June 23, 2021 by Charlie69