850 clutch/crank movement

[MoSnow]

Hi all. I just picked up a 2018 gen4 summit and when I grab the primary clutch and move it up and down with a bit of force, I can feel a slight clunk and it’s hard to see but looks like the inner sheave is moving in relationship to the engine. If this is the case is the clutch moving on the crank stub or does the crank actually have play in the engine? It seems to do it more at certain rotation points on the clutch than others and is almost nonexistent in some spots. I can’t duplicate this on my XM. I haven’t been able to drive it yet with no snow but it seems to run just fine. I went into the dealer today and even the brand new 2020 had a tiny amount of this noise/movement. Is this normal or anything to be concerned about? Thanks all in advance. Cheers!

 

[MoSnow]

Does anyone have an explanation for this? Can you duplicate this sound/movement on yours?

 

[Ries]

Hand same problem on my 18 g4 took it to dealer they checked crank spec and said it was fine 200 hundred miles latter it blew up and they got to put a new motor in it
Have 2 other 850 g4 and they have no slack at all one is a 17 and the other is a 18 and they are still running

 

[MoSnow]

Thanks a bunch for the reply. It’s the answer I didn’t want to hear but kind of expected... better get some miles on it before February! That’s when the warranty is off....

 

[el__gato]

keep us posted, if it moves like you are saying i'd be surprised it runs at all.
thanks.

 

[MoSnow]

Will do! Once we get snow I’m gonna hold it to the bar and see what happens!!

 

[Teth-Air]

Will do! Once we get snow I’m gonna hold it to the bar and see what happens!!

They had some motor mount issues too, any chance you can feel them moving around?

 

[MoSnow]

I was thinking the same thing but to me it seems like it’s coming from the engine itself. Especially since it is worse it some parts of the rotation than others. I’m not even sure how that could happen. Maybe flat spots in the bearings or a bent crank but it seems to run really smooth on the stand at least. It’s weird that I could feel it on a brand new unridden 2020 as well. Just not to the same extent. I’ll have to check some others. It moves such a small amount that it’s tough to see but you can feel it and it’s not the clutch. It also feels/sounds like a tiny bit of slop when you roll the clutch back and forth. Not the same sound as the clutch arms falling and clicking. Should you be able to hear/feel that?

 

[Trashy]

Put a dial indicator on it and you’ll know for sure.

 

[Ox]

Put a dial indicator on it and you’ll know for sure.

I just kan't hardly imagine being able to see or feel (hear?) any amount of slop in a crankshaft that is still in a "running" engine.

Although - with direct injection, I'm guessing that crank seal / lean mix is not a common burn down anymore?



.

 

[MoSnow]

I just kan't hardly imagine being able to see or feel (hear?) any amount of slop in a crankshaft that is still in a "running" engine.

Although - with direct injection, I'm guessing that crank seal / lean mix is not a common burn down anymore?



.

I feel the same way. I have’t rode the sled yet but it seems to run great in the shop. I’m hoping to pull the clutch this week and see if I can move the crank stub at all by hand. I’ll try and check runout if I can too. Anyone know the runout spec on these engines?

 

[Ox]

I'd like to think that any movement that you are seeing would all be in the moving half of the clutch.

 

[snowryder]

Hi all. I just picked up a 2018 gen4 summit and when I grab the primary clutch and move it up and down with a bit of force, I can feel a slight clunk and it’s hard to see but looks like the inner sheave is moving in relationship to the engine. If this is the case is the clutch moving on the crank stub or does the crank actually have play in the engine? It seems to do it more at certain rotation points on the clutch than others and is almost nonexistent in some spots. I can’t duplicate this on my XM. I haven’t been able to drive it yet with no snow but it seems to run just fine. I went into the dealer today and even the brand new 2020 had a tiny amount of this noise/movement. Is this normal or anything to be concerned about? Thanks all in advance. Cheers!

Did you ever find out what was causing this? My 2017 with 1900 miles on it is doing the same thing. A definite clunk when moving the primary up and down. Best I can tell it's either rocking on the taper or its play in the crank bearing. Both seem unliklely but doesn't seem to be coming from anywhere else at this point. Engine seems to be vibrating more than before which is why I found the apparent clutch/crank movement while checking it over. Dealer looked at it and said runout was within spec and they couldnt find anything else "out of spec".