How-To: Fix GMT800 Idler Pully Squeek For FREE.

y2kz71 · January 18, 2008

dang good info

LGillingham · March 10, 2008

The Upper Idler pully on my 2001 Tahoe was squeeling.. Really bad in the morning and then would eventually do away as it heated up..

I was going to replace it for about $50 or $60 bucks but decided to pull it it off this afternoon and check it out first...

I am told they are one piece and must be replaced and are not repairable.. WRONG...

Here are the steps..

1. Grab the center pully bolt with a 15mm socket and turn it clockwise to relive the belt tension and remove the belt.

2. take the pulley off by turning the same bolt Counter Clockwise.

3. Once off and on your workbench you can then see the bearing covers on both sides..

4. You need strong sewing needle to get the covers off.. Start carefully on the edge of the cover. (It's made of some sort of hard rubber) get underneath it and pop it off. Do the same for the opposite side.

5. You have now exposed the roller ball bearing race. One sode you can actually see the actual ball bearings

6. It's most likely dried up pretty good in there and you need to regrease them. I used some high temp caliper grease but you can probably use any high temp grease. Simply put a dab in between the spaces on the exposed ball bearing side. I even put one drop of Mobile 1 to help keep it loose..

7. Snap the covers back on and make sure they are snug.

8. Reinstall the pully and away you go..

9. Take the saved money and take your Wife or Girlfriend to dinner..

Here is the picture below of all the parts...

I had a similiar issue on both a 1500 and a 2500 Sierra. I was told the same thing that the whole unit had be changed. When you look at it closely the bearing is molded into the plastic pulley so I used a dremel to grind off the molded plastic holding the outer race of the bearing on the engine side of the pulley. I was then able to press out the bearing, go to a local bearing shop and get a replacement (dirt cheap) and press in the new bearing. The fact of the matter is that this bearing does not need to be molded into the pulley -only there for the GM finances - when fitted in location on your vehicle it is secured by the bolt and washer on one side and the stop which rests against the inner race on the other side. I did this for both idler and tensioner pulleys - problem solved.

n0dih · April 8, 2008

I just bought the new bearing for $5 at local parts store, took me all of 2 min to hammer the old dry one out and hammer the new one back in... Mine is a 99 K2500 454 Suburban. Maybe they got cheap on the newer rides.... But the older ones used a metal pulley.

So always check for the bearings, they are readily available....

I just performed this quick fix on my 95 Chevy.. took me all of 10 minutes and worked like a charm!!

Thanks for the heads up!

Pancho · September 11, 2008

Replaced belts (went w Goodyear Gatorbacks again) today and decided to give this a try. It was so easy I now wonder if there is any downside? When buying grease the guy behind the counter asked if I needed anything else. He was prompt to remind me that those bearings are sealed and need to be replaced. I am confident that he expects me back for the replacements as he said I was wasting my time. Anyway, upper was completely dry and the lower had some signs of having had some grease on the back sides of the the covers once upon a time.

jonezy00 · October 30, 2008

what was the part number on the bearing?

Mik3M · November 1, 2008

Mine too has been sqeeekin for a long time, only in the am, and especially when wet. I don't have the plastic pulley you show, but rater a smooth metal pulley. It was slippen on the back of the belt. I took an angle grinder, and a rolock disk to roughen up the pulley to fix it. SO far so good.

ricko2 · November 1, 2008

I'll give it a try. What have I got to loose?

ricko2 · November 3, 2008

Oh well. My alternator bearing is the one making the noise, not the tensioner or the idler.

zz50 · November 9, 2008

Bearing part number is 6203 with neoprene seals on both sides. This is the same for the tensioner pulley (palstic) and the small smooth flat pulley next to the alternator. I found both of these pulleys new for less than $30 @ rock auto. Yes, it is still cheaper to grease but if the bearing is shot then this is a good alternative.

what was the part number on the bearing?

zz50 · November 9, 2008

If it was slipping there then there is probably something seizing up. Roughing that surface wil only accelerate belt wear. These belts are designed to be used for drive on both sides not only the grooved side. The smoother the surface the longer it lasts. Good luck

Mine too has been sqeeekin for a long time, only in the am, and especially when wet. I don't have the plastic pulley you show, but rater a smooth metal pulley. It was slippen on the back of the belt. I took an angle grinder, and a rolock disk to roughen up the pulley to fix it. SO far so good.

jtupper · November 19, 2008

I did this on Friday and it worked like a champ...for a few days. I noticed this morning that the chirping is back. I even noticed it yesterday morning, although it was very faint. I used wheel bearing grease. I did the tensioner pully and the small pulley directly behind the fan. Is that the idler pulley???

I absolutely HATE that damn noise in the mornings. It takes a while before it goes away on mine. When it's really cold it doesn't go away at all sometimes.

tlanham1213 · July 18, 2014

Hey guys. I have a '99 GMC Sierra SLT 2500 4x4 with 185k miles. I have a chirping/belt squelling sound udder the hood. I've listened with a stethoscope to isolate the problem. This thing is really kicking my butt. I've replaced the alternator, power steering pump and reservoir, water pump and thermostat, brake booster, upper belt pully, idler pully, tensionor pulley, new belt twice,a/c compressor, accumulator, orifice tube, a/c belt, radiator, new radiator fittings, new metal lines and transmission line. The only item that hasn't been replaced is the harmonic balancer and pulley. When idling there is no noice, rev engine and chirping/ squelling noice sounds and never goes away. PLEASE HELP! This thing is driving me nuts. Thank ya'll in advance. You guys have built one great forum.