# Pulley bearings. When it spins freely. Why exactly is this bad? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [April 18, 2012, 3:08am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972 "2012-04-18T03:08:26Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![UsedEconobox\_2\_UsedBMW](https://avatars.discourse-cdn.com/v4/letter/u/8491ac/32.png) [@UsedEconobox\_2\_UsedBMW](https://community.cartalk.com/u/UsedEconobox_2_UsedBMW)\ **Post date:** [April 18, 2012, 3:08am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/1 "2012-04-18T03:08:26Z")
Listen to the bad pulley. What has happened inside? It spins freely, no resistance. Unlike when new. But, why isn’t this a good thing? (Less resistance…) ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [April 18, 2012, 3:20am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/2 "2012-04-18T03:20:58Z")
If you spin any kind of sealed bearing and the bearing makes any kind of noise it means the factory lubricant is gone. The noise is caused from the rollers in the dry bearing spinning on the races in the bearing. Tester ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [April 18, 2012, 3:45am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/3 "2012-04-18T03:45:12Z")
It’s not a case of less resistance. The pulley may be turning at an acceptable rate today, even though its bearings are now dry. However, at an unknown point (tomorrow, or next week, or in the middle of your next highway trip), the bearings in that pulley will seize, and at that point, the serpentine belt will shred/self-destruct. This is something that you want to avoid–unless you relish the idea of needing a tow from the shoulder of a high-speed expressway, or a dodgy neighborhood, or some other dangerous area. ---
**Author:** ![UsedEconobox\_2\_UsedBMW](https://avatars.discourse-cdn.com/v4/letter/u/8491ac/32.png) [@UsedEconobox\_2\_UsedBMW](https://community.cartalk.com/u/UsedEconobox_2_UsedBMW)\ **Post date:** [April 18, 2012, 4:19am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/4 "2012-04-18T04:19:54Z")
See 4:00 in the video. Ok, so this means the lube is gone, and eventually it WILL seize. Thanks! ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [April 18, 2012, 4:42am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/5 "2012-04-18T04:42:44Z")
Good info. ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [April 18, 2012, 5:19am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/6 "2012-04-18T05:19:11Z")
Good ball bearings run silently…Polished steel against polished steel, lubricated…Smooth as silk… First the seal goes…Then the lubricant goes…Then the bearing wears and gets rough…The balls start to jam and slide…The bearing fails…The pulley stops turning or fly’s off… ---
**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\ **Post date:** [April 18, 2012, 6:46am UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/7 "2012-04-18T06:46:21Z")
…and that’s when you wish you had your video camera rolling. ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [April 18, 2012, 7:12pm UTC](https://community.cartalk.com/t/pulley-bearings-when-it-spins-freely-why-exactly-is-this-bad/71972/8 "2012-04-18T19:12:37Z")
While in operation the pressure and speed would make for a much different situation. If manually turning such a device indicates that it is free wheeling the balls are not rolling indicating that they are flat spotted and useless.