2010 M8 Broken primary spring

AKDMAX1 · Dec 16, 2009

Just pulled the sled into the garage to thaw it out and check things over as I always do after I ride. So i was looking at my clutches and noticed that my primary spring was broken. I only have 150 miles on the sled. It's on of the black/orange springs. Has anybody else had a spring break on their 2010?

newtrout · Dec 16, 2009

Take a look around the edges of the spring at both ends. Just like my '07 M8, my 2010 primary spring is making a lot of contact with the spring cup on the cover and spider ends. There are serious wear marks on the spring after 150 miles. Can't say for sure that this is causing breakage, but it isn't good. I can't believe they haven't fixed this problem yet. At the very least, it cranks up the finish rate of your primary spring.

It's pretty easy to remove some material from the cover side. The spider end has a pretty deep cup. You'll have to remove quite a bit of material to stop the contact. Because it's so close to the rotational center of mass, I wouldn't worry too much about balance.

Since the primary hasn't changed from the '09s, and I don't think many '09s had spring breakage problems, it's probably related to the new spring as well. Apparently its the same spring as the orange/white, but from a new vendor. Low bidder I'm sure......

powderpounder · Dec 16, 2009

We had one with a broken primary spring.

AKDMAX1 · Dec 16, 2009

Ya, I have some suspicions on it having some coilbind. Im goin to go talk to my dealer tomarrow and see what they are goin to do for me .

AKDMAX1 · Dec 16, 2009

powderpounder said:
We had one with a broken primary spring.

Did it happen to be the second coil from the bottom? Ive got pictures but to computer dumb to get them on here.

KAWGRN · Dec 16, 2009

I just went out and checked at the prescribed height and it does not coil bind and mine measures at 145-310 spring new ,,,I pulled it out and put a polaris spring that is 105-320,, 4000 engagement and 8250 rpm with 68s the poo spring is a short 4inch spring

powderpounder · Dec 16, 2009

Yes that was it broken near the bottom. I am a dealer and customer noticed it when he was changing weights and I gave him a slp 120-320 spring to try. We will see if this becomes a real comon problem. So far the first issue we have seen on a 2010 m8 and he did not even notice a problem till he happened to come across it.

AKDMAX1 · Dec 16, 2009

The only thing i noticed that i can think of now is that it was engaging alote lower than before, but it was still smooth so i think that the only way you will know is to physicaly look at clutch

Coxy · Dec 17, 2009

This has been an issue since at least 05. The spring cup as mentioned above is too tight on the spider, as the spring compresses, it swells in diameter, especially when it cant twist, and chews on the cup. Take a look at any stock sled, you will see the paint missing off the first 3 coils on the spider side. My 05m7 did this, the new replacement clutch did this, my 09 did this and did indeed break the spring. You'd think cat would have figured this out by now

ripsass · Dec 17, 2009

At 500 miles the pri spring on my 09 is missing a LOT of paint around the outer edges of the coils... Time for a trip to the lathe.

XFIRE800 · Dec 17, 2009

I swapped out my primary spring at about 750 miles and i dont think there was any paint missing. I will have to check for sure though.

geo · Dec 17, 2009

'10 primary clutch is very much different from the '09 clutch is you really look (so is the secondary). Small important changes, but all for the better.

The new spring coil binds sooner than the old orange did.

I've been using the D&D white ( similar to if not the same as the SLP and Pol springs listed above but fits better cause smaller OD) for a few years. Nice to tune with and engagement between AC gold and Yellow-White.

Geo

thekrust · Dec 17, 2009

I just pulled a broken '10 M8 primary spring from a customers sled today. This seems to be theme here. I'm wondering if this is a binding problem or just a crappy product farmed out to the lowest bidder.

AKDMAX1 · Dec 17, 2009

Ok, so i just got back from the dealership and they warrentied my spring as i figured they would and they gave me a orange/white, which they say has the same rate as the black/orange. He was telling me they have had almost every sled they sold with that spring come back with the same thing, broken in the same spot. So I know this orange/white spring has been around since the 90's so we'll see if its a coilbind issue or bad batch/designe of springs.

slyrydr · Dec 17, 2009

broken primary springs on big twins has been a problem for many years....i totally solved this problem many years ago....the problem, is that as the spring cup starts to wear, 1 or 2 rides, the spring gouges the cup (face plate of the clutch), the more it does this, the more it coil binds, because it can't rotate anymore.....the solution..

...put a delrin washer, or stainless steel or nylon, in the cup such that the spring seats on the washer....now the spring has something to rotate on instead of gouging the metal cup....i haven't had a broken primary spring in about 8 years...knock on wood..

dtaylor · Jan 3, 2010

spring

yep mine broke today 300 miles on it.........2010 800 sp

capri302 · Jan 4, 2010

Here's mine, 162" 2010 with 700 miles

tsnowak · Jan 4, 2010

the clue for this is you notice all the sudden it engages signifigantly lower than before as akdmax1 stated. Like around 3000-3500rpm. if it does take a look at the spring, has been breaking on the second coil from end.

Geo- for the binding, would a primary shift assist be a fix? thought the newer 09/10 primarys had more width in the spring pocket to help that issue.

LFM1 · Jan 4, 2010

2010 M8 HCR with 300 KMs. Broken Primary spring. Didn't even notice a change in performance, check your springs!! Dealer warrantied it no problem. Will see how many more Km's I get out of the new spring.

colorado_matt · Jan 4, 2010

I found my broken spring at 210 miles. 2010 HCR. Only other sled I've broken a primary spring on is my 07 M1000.

2010 M8 Broken primary spring

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