Polaris 850 crankshaft

[drewb16]

I have a 2019 Polaris rmk pro 850 that a bearing in the crank sized up so I am rebuilding the engine. Today I received a rebuilt kit in the mail and noticed 2 of the bearings on the crank has a retaining ring around it which my previous crank did not have. After researching it I learned that in 2020 they added those rings and put a notch in the crank housing to keep the bearing in place. My engine does not have those small grooves to accommodate those retaining rings. I was wondering if I could just remove those rings and use loctite 603 to keep the bearing in place and use this new crank I just got if that would work fine or if I need to send back the crank and get a different one. Thank you!

 

[Kylep]

I have a 2019 Polaris rmk pro 850 that a bearing in the crank sized up so I am rebuilding the engine. Today I received a rebuilt kit in the mail and noticed 2 of the bearings on the crank has a retaining ring around it which my previous crank did not have. After researching it I learned that in 2020 they added those rings and put a notch in the crank housing to keep the bearing in place. My engine does not have those small grooves to accommodate those retaining rings. I was wondering if I could just remove those rings and use loctite 603 to keep the bearing in place and use this new crank I just got if that would work fine or if I need to send back the crank and get a different one. Thank you!

Id contact indy specialties and see what he thinks

 

[DITCHBANGER]

yeah call indy, dont listen to backyard mechanics. might as well do it right

 

[drewb16]

I got a hold of my Polaris dealership and they said to just pop that ring off and loctite it on and it will be good. Maybe I will call Indy tomorrow and talk to him to make sure if someone has a contact for him. Thanks for the help!

 

[thamax]

Buy the newer crank cases or have yours machined to add the grove for the snap ring

 

[madmax]

I’ve had the 19’ case machined to use the newer bearings. It cost $100. Well worth the piece of mind. you can just take the positioning rings off the bearing, but then you risk the bearing seizing again

 

[208_RMK]

Polaris made that change for a reason.

 

[Ken65]

Id contact indy specialties and see what he thinks

I don't think it's anything a 4 1/2" grinder couldn't fix.

 

[Kylep]

I don't think it's anything a 4 1/2" grinder couldn't fix.

Lots of green loctite too haha

 

[diamonddave]

I would PM Chadly. He’s the forum expert and will give you the best advice.

 

[drewb16]

Thank you guys I think I'm going to take that ring off and use loctite 603 to keep it in place. Another question I just came across was I am putting the mechanical seal on the water pump and saw in the service manual you need a special tool to press it in. I was wondering if there's a way to do it without that special tool such as a socket or if that tool is absolutely necessary to seat it at the correct depth

 

[H2O]

Send your cases to Indyspecialty to have the groove machined inside like the 2020+ factory cases. "Gluing" the bearing in place without the locator ring will lead to the same failure you already experienced. Since it's already apart now is the ideal time to fix the 2019 motor.

 

[BeartoothBaron]

If it were me, I'd also have the cases machined for the retainer ring. Sure, most '19s didn't fail because of the lack of the locating ring, but some did. Seems worth the price to buy some extra insurance. You might not need to send it anywhere either; it's not anything too technical. It might take a few calls, but I'd think you could find a machine shop that could handle it. Someone really brave could probably do it by hand. But it's not like it's a guaranteed failure if you don't, and it's your sled either way. On the water pump issue, I'd have to see it to say for sure, but it could just be that the special tool is more for convenience - maybe it has more to do with setting the seal at the right depth than anything else. You definitely want to take a close look at the old seal and make sure you match that when you replace it. The other part of it is making sure you're not doing something that'll damage it. If you've driven a few seals in your time like me (and ruined a few), you'll probably find this one is no different.

 

[MARV1]

Definitely get the updated crankcase or get your current one machined for the ring. My 2019 850 went 6200 miles before that PTO bearing walked and seized up. Rebuilt it to 2020 newer crank and cases with dual ring Wossner piston kit and Indy specialty billet head. Waiting on engine mount to get it back together and running