1M 900 Broken clutch bolt question.

[m_beeson]

Dad has a 2004 1M 900. Bought it this year. I was told to look closely at the clutch on those, since they have a weak spider gear.

Long story short, I put a comet 108exp on it. Since then I have broken two retainer bolts. I noticed that the AC clutch had a dampener that went inside of it. The comet didn't have anything like that. The first one didn't come with a lock washer, so I put one on the second Bolt that I put in it.

I know the 900 has a lot of vibration, but two broken bolts in one year?

Checked the crank with a dial indicator, and it was good. Torqued it to spec.

I would apreciate it if you can throw some thoughts / Ideas my way. I'm perplexed as to why I would be breaking bolts.

 

[76FOMOCO]

motor has a bad internal bearing, or piston giving harmonic vibration on the pto side.

 

[m_beeson]

motor has a bad internal bearing, or piston giving harmonic vibration on the pto side.

Thanks a lot fomoco
You couldn't tell me I needed bolt dampeners like on the AC clutch, or something simple and inexpensive could you.

 

[76FOMOCO]

if your lucky and tear it down and find nothing your only out your time and a few gaskets. if i'm wrong your out a crank. have a other guy battling the same thing but on the fly side keeps losing magnets. anybody else please chime in.

 

[76FOMOCO]

btw the damping ring was used on the m7 only that i know of.

 

[Idcatman3]

We've been using the dampener ring on all our sleds for a couple years, it really tamps down the vibrations, especially at low speeds.

The only magnets we've ever lost were because the flywheel came loose and hit the stator

 

[m_beeson]

I have ordered the new bolt. "again".

I'm going to pull the clutch again, and install the harmonic ring from the AC clutch.

I have already checked the crank with a dial inticator, and found that It was way within tollerances, and my suspicion is that the jugs have never been pulled on this sled. (It only had 400 miles on it when we bought it) so hopefully the pistons aren't the culprit.

I know that these 900s are notorious for harmonic vibrations, so Hopefully the ring will do the job. If not then the next step is a tear down.

 

[CatndHat]

this will not hurt as an upgrade

I installed the hiem link engine torque stabilizer offered by SLP years ago for the front motor mount.
Saves belts, holds the engine from excessive vibs and helps the rubberized mounts for premature break down. I do think it keeps the belt cooler from less
belt torque deflection.
May help in the bolt shear issue also. Bolts to the front aluminium bulk head
support and the front engine mount, cheap upgrade so check it out at the SLP site. Think I added two heavier durometer mounts at the same time also.

 

[stock suks]

wrong size inside bearing diameter?? not seating all the way, dont know just a crazy maybe possibility