Pro RMK clutch failure

[Snodawg]

Has anyone ever seen a clutch failure like this? About 650 miles on the sled, 100% stock. Warranty should cover it no problem. Also, the grooves wore into the inner edge of a brand spanking new belt.

 

[die hard poo]

Wow looks like there's some bad P-85 Primary clutches out there. Mine didn't do that exact same thing, but mine did this...

 

[trikerider]

After seeing it on the IQs it's one of the check after every ride things. I reach down and grab the clutch and make sure it's good, I also take a flashlight and check for cracks.

 

[diamonddave]

Wow looks like there's some bad P-85 Primary clutches out there. Mine didn't do that exact same thing, but mine did this...

Snodawg's is about to the point of doing what yours did.

This type failure of failure has been happening more frequently over the past 2 years. It's not common, but it is happening more than one might think. I saw 2 Pro's with this over last New Years.

 

[Snodawg]

Mine is not really a crack, it is just the inner sheave is loose on the clutch shaft where the aluminum is pressed onto the steel. I'm not sure if this would have broke off or not.

 

[rmkboxer]

I wouldn't touch it and let the dealer do it, the sleeve isn't going to come off the crank with a puller. good luck.

 

[94fordguy]

Strange.... I wonder why this type of failure has become so common on these things

 

[PR Performance]

Had a primary on an 09 assault shear in half 15 miles from trailer in the snowies, what a long pull that was. sled was out of warranty, and it ended up taking the whole motor once we put the new primary on as the crank must of spun out of phase, 100 miles after the new primary we had to buy new crank pistons and cylinders, be real careful when you put the new clutch on. I would check the crank for some wobble and pistons for being out of phase, just letting you know what happened to us.

 

[03RMK800]

Strange.... I wonder why this type of failure has become so common on these things

What I have been told is that the shaft wall was made thinner as part of the change in taper. I guess it saves weight, to have a thinner clutch shaft.

The lower weight made no difference to me when we had to drag my sled out ten miles when the clutch broke. No sound quite like an engine going from about six grand to zero in a revolution.

 

[Snodawg]

Dropped off my sled at the dealer tonight, I will pick it up in the morning with the new clutch installed, then we're hitting the mountain in the afternoon. While the clutch is off, I'm having them check the crankshaft out.

 

[suitcase]

Thats ugly!!!
question? could that be a crank problem?

 

[03rmking]

Wow looks like there's some bad P-85 Primary clutches out there. Mine didn't do that exact same thing, but mine did this...

Mine did that exactly. Dealer that originally sold my sled said they had warrantied 16 clutches with the same failure...that was 3 months ago.

 

[EricW]

Strange.... I wonder why this type of failure has become so common on these things

A very trusted friend ( I send all my stuff to Indy Dan) told me that its possible that the spider jam nut in the primary was not torqued or loc-tited properly allowing it to loosen when reverse is used. Once the assembly is loose and you have an over rev from getting air or a hard torque spike it can slam back tight and shear. When we boosted Westons '09 sled this year thats exactly where his was at. It just spun with the clutch puller. Spider jam nut was backed way off.

I think it has to be something like this since we have little or no trouble with the older P-85's on our boosted sleds making it hard for me to believe that a whopping 145 hp is doing all that damage.

I keep 2 Indy Dan makeovers on the shelf at all times and change out even new clutches right away. He still finds room for improvement on OEM stuff that has never seen snow. Cheap investment compared to the carnage shown. EW

 

[Snodawg]

My dealer swapped out the clutch and installed a new belt Friday morning. Crank runout was perfect. Picked up the sled at 10:00, was on the snow by 12:30 (had to test ride a couple of KTM's while I was there (still like the 380 2-smoker better)). Had a great day at Tampico, got home at 9:30. Everything works great. However this summer, I think I will either send my clutch out to Dan or Carl's for a rework. Still not hitting 8250 with 10-64's, stock spring. Lucky to see 8000-8100. (3000 to 7000 elev.)

 

[FTXMOTORSPORTS]

snodawg-you need less final angle on the helix-try a 40 final...

there were a bad batch of p85's this season-most have been caught already as they failed quickly.

this is not an ongoing issue but a bad mfg batch.

has nothing to do with the growth of the taper-we take that same clutch and machine the taper bigger and deeper (for the cats) and have NEVER had a failure related to the taper in a p85-even back to the old narrow roller p85.

definitely great advice above-always check run out after a belt failure-let alone a clutch failure!

Curt