Motor/Spline Bumper


Does anyone have the part # for the proper motor/spline Bumper?

I have replaced mine twice now with the one from NEV and it wears out too quickly. I get maybe 20-30 miles out of them before I get the clunk sound. I have even tried a dime behind them.

When I install them, the gem drives and sounds like new. Totally silent.

I remember the original I pulled out did NOT look like the one NEV sells. It looked more like a star or sun. :sunny:

Not this one…image

Maybe it’s the 3131m smooth style and it gets the star shape from compression?

Anyone else have this issue with NEV motor bumpers?

This is the official part. “OEM Polaris BMPR RESILIENT-DIFF TO MOTOR 5414407”. It comes splined and definitely works better than the smooth ones many are selling. I get them from I buy 5 at a time because the shipping will kill you otherwise. They should be replaced fairly frequently and every time you have the motor off. I burned through a lot of them chasing a leaky seal.
Be VERY careful with the dime trick! I lost a motor to overheating doing that one. The warning signs were there but I missed them and overheated the motor so bad the armature got destroyed. It was nice and quiet while it lasted though :slight_smile:
Also, be sure to lube the splines before reinstalling the motor. It definitely seems to make things quieter. Below is the link to the bumper:

Thank you my good man! Big, big help. Hopefully I can return the favor at some point.:sunglasses:

Hey Vern. Check this out. Ordered the bumper from the link you provided. Look what came…a smooth (non-splined) bumper. Not the splined one.

Does anyone know which bumper comes splined? Not the 10 spline above but the 19 spline or whatnot.


Smooth is what you want. The rubber will actually smash into the splines and will end up being splined from the force of doing its job. The one you took out almost certainly was smooth when it started life. Weird isn’t it?


Perfect! That’s great news. Thought the hunt was on again. :sunglasses::+1:t2: Thanks!