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Replacing Pulley Bearings as Preventative Maint??
Today, I am replacing the pictured Dayco pulley as preventative maintenance as it looks quite old / possibly original. Does anyone replace the bearings in the other (green) pulleys as preventative maintenance? What about the bearing to fan radiator belt?
Curious as believe it would be difficult to “hear” a chirping, failing bearing over the sound of an idling engine… THANK YOU
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4 Replies
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With over 400,000 miles spread between three coaches I have never replaced a pulley. I have replaced a bearing in an idler pulley that actually did not make contact with the OTR belt unless it started slapping.
I do a periodic pulley inspection, engine off, belts loose and I rotate every idler pullet. If I feel any roughness, or hear any growling, or sense any looseness I will deal with it. But other than the bearing replacement on my first coach I have never had an issue. You will never hear a bearing noise with the engine running which is why I loosen the belts and rotate and feel the pulley.
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In addition to Jon’s post there are one of two things which would tell me to replace this pulley pointed out in picture.
A ) Noise and / or excessive end play leaking grease appears splattered around the spinning pulley.
B) Excessive jumping coming from spring which is located behind the black cover. Most shops will push for an replacement as general life at 100,000 thousand miles.
Then carry the old one as a spare.
Another check is rubber packing in bottom of pulley groves. Clean this away dirt so to allow your serpentine belt to lay completely enclosed in pulley surface.
AL
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Because of this post I checked my pulleys and notice oil leaking from the back side of the black pulley on the left side of the above picture. I believe this is the gear driven pulley.
I assume (and we all know what an assumption is…) this is a simple matter of ordering a new pulley assembly and bolting it on.Any additional thoughts before I proceed on my assumption?
Chuck
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I had two idler pulley bearings go dry and intermittently lock up several years ago. The bearings would spin fine when tested by hand. I had a heck of a time figuring out what was happening. The serpentine belt would partially walk off the pulley and get cut at the pulley fence. The frayed belt would whip around and unscrew the oil filler…. In the end, the belts would only last a couple of hundred miles.
I replaced the old fixed tensioner arrangement with the newer automatic belt tensioner with new idler bearings. No problems since.
The bearings can be replaced if you are careful in pressing them out of the pulley. The cast pulley breaks easily. Ask me how I know.
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