bearman
Active Member
I just burnt up one of the new 9-plate clutch packs in my '06 Mastiff after replacing the old 12-plate clutch pack with really needing too (hindsight is a bitch).
I figured out why after I took it back apart. It turns out that it had nothing to do with the number of plates, but the installation order.
I have the EFM Auto clutch in my Mastiff, and it uses the stock basket and hub, so I'm not sure if this applies to all clutches or not but I figured it couldn't hurt.
The service manual says the last plate put in should be an 0.80 thick steel disc. It turns out that mine (as it came from EFM assembled) had a friction disc as the last disc, and not only that, the next one was also a friction disc.
Long story a little shorter is that I put a friction disc in last and then a steel next and this allowed the first steel plate to come completely off the hub when the clutch was disengaged and then hang up when the clutch engaged. It actually wore a chamfer on the end of the hub.
The 9-plate clutch pack actually came with 10 discs so I goofed up and tried to use all 10. It seems that the difference between the 12 and 9 plate clutch pack is the thickness of the steels. The stock 12 plate pack uses 0.045" steel discs and the 9 plate pack uses all 0.080" steel discs. So I mixed and matched my old and new steels to get a usable clutch pack height that used all 10 of the new friction discs.
The service manual states that the installed clutch pack height is supposed to be 1.957" to 1.603". It doesn't say if this includes the 0.120"thick inner hub packing plate. My stack without the inner steel measured 1.86", my new stack measured 1.94". After I burnt the new one, it only measured 1.79".
The manual says that new friction discs measure 0.090" and the wear limit is 0.0085" making the minimum thickness 0.0815". My old ones were 0.085" and the new ones were only 0.086"
The reason I burnt mine completely up is that it was only slipping some at first, but as the clutch wore, it got to where the clutch cable adjustment was too tight and then it burnt completely before I realized and loosened the cable. I don't normally use the clutch lever with the auto clutch.
The only reason I went into the clutch in the first place was that sometimes while slow speed maneuvering (like in a parking lot or the driveway) I would have to rev the engine way up to get it to move at all. Well today before I tore it down I found that culprit is a too short (or mis-routed) clutch cable. When I turn the bars all the way to the right side, it pulls in the clutch.
I put the old clutch pack back in and mixed and matched the steels to get a clutch pack stack height of 1.92".
I also put the same two friction discs in last. But because of my chamfered inner hub I was afraid of hanging up again, so replaced the last steel with a friction disc and now my last 4 discs are friction. That means that I am basically running on only 9 friction discs.
So far, it works better than it ever has and holds fine in all gears, and I hammered on it pretty good today.
I figured out why after I took it back apart. It turns out that it had nothing to do with the number of plates, but the installation order.
I have the EFM Auto clutch in my Mastiff, and it uses the stock basket and hub, so I'm not sure if this applies to all clutches or not but I figured it couldn't hurt.
The service manual says the last plate put in should be an 0.80 thick steel disc. It turns out that mine (as it came from EFM assembled) had a friction disc as the last disc, and not only that, the next one was also a friction disc.
Long story a little shorter is that I put a friction disc in last and then a steel next and this allowed the first steel plate to come completely off the hub when the clutch was disengaged and then hang up when the clutch engaged. It actually wore a chamfer on the end of the hub.
The 9-plate clutch pack actually came with 10 discs so I goofed up and tried to use all 10. It seems that the difference between the 12 and 9 plate clutch pack is the thickness of the steels. The stock 12 plate pack uses 0.045" steel discs and the 9 plate pack uses all 0.080" steel discs. So I mixed and matched my old and new steels to get a usable clutch pack height that used all 10 of the new friction discs.
The service manual states that the installed clutch pack height is supposed to be 1.957" to 1.603". It doesn't say if this includes the 0.120"thick inner hub packing plate. My stack without the inner steel measured 1.86", my new stack measured 1.94". After I burnt the new one, it only measured 1.79".
The manual says that new friction discs measure 0.090" and the wear limit is 0.0085" making the minimum thickness 0.0815". My old ones were 0.085" and the new ones were only 0.086"
The reason I burnt mine completely up is that it was only slipping some at first, but as the clutch wore, it got to where the clutch cable adjustment was too tight and then it burnt completely before I realized and loosened the cable. I don't normally use the clutch lever with the auto clutch.
The only reason I went into the clutch in the first place was that sometimes while slow speed maneuvering (like in a parking lot or the driveway) I would have to rev the engine way up to get it to move at all. Well today before I tore it down I found that culprit is a too short (or mis-routed) clutch cable. When I turn the bars all the way to the right side, it pulls in the clutch.
I put the old clutch pack back in and mixed and matched the steels to get a clutch pack stack height of 1.92".
I also put the same two friction discs in last. But because of my chamfered inner hub I was afraid of hanging up again, so replaced the last steel with a friction disc and now my last 4 discs are friction. That means that I am basically running on only 9 friction discs.
So far, it works better than it ever has and holds fine in all gears, and I hammered on it pretty good today.
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