05 M7 Clutch Mod--HELP!!

[wart]

I know this has been beat to death in the past, but I'm not finding exactly what I want in the search. Can anybody please refresh me on the clutch mod to machine the faces of the secondary to accept the larger belt. I can't remember what the specs where and what belt had to be used. Has this been working okay now that there has been some miles put on? Is it worth it?

Thanks!!!!

 

[wart]

Anyone???

 

[slomo]

it's pretty cheap to just buy a 10.4 secondary rather than machining the 10 and the belt i use is the 046 cat belt

 

[furthur]

It's often cheaper to machine the clutches, but at this point, you have to wonder if your '05 secondary is worn out.

Forgot to add, I didn't capture those measurements last time it went around...should have. I promise to write it down this time, if someone posts it...

John

 

[Barrett]

I cut .055" from each sheave, on my 10". you can also do this to the 10.4 and run an even longer belt (46 9/16"). it will give you that much more usable shift range in the primary, and minimize the amount of OD, for the most efficient clutching possible IMO. you will need a deflection adjuster, I used the black diamond one http://bd-xtreme.com/bdxbeltdeflectionadjusterright.aspx
Barrett

 

[wart]

Thanks Guys!!! The BD website also has the 10.4 sheaves for about $200...will probably just go this route. Already have their adjuster so hopefully this mod makes a big difference.

 

[Ski-Laxn]

What are you trying to gain from the 10.4?

 

[wart]

The problem with the stock 10" is several problems....(1) Glazes belts very quickly ecspecially when clutches get a little warm (2) harsh engagement (3) higher gear ratio or trenches more (4) the '06's that had the same motor with the 10.4" would eat me alive and their motors were stock, mine has a few goodies.

I'm sure there are more reasons.

 

[Ski-Laxn]

Ok here is what I have found. Harsh engagement is due to the belt deflection on the primary. I was at .060 and reset to .025 harsh engagement gone, With the 10.4 0n my 05 I did not feel any change (does not change the distance the belt travels in the primary. I was not looking for topend. I changed second sled to 54/66 gearing and that gave me my lowend and it pulls very hard climbing. If you change to the 10.4 the belt is very hard to change due to clearance. IMO i would change gearing instead of clutch.

 

[wart]

I've worked on the clearence problem and need to find different shims or something. If you go with the 10.4" and use an 046 belt it shouldn't be much harder to change belts than the 10" with the 036 should it? I'll check into gears.

Thanks!!

 

[Ski-Laxn]

your clearance between the belly pan and the foot rail is very minimal with the 10.4.

 

[wart]

10-4.....The 10.4" models have more of a dip in the belley pan to account for this. It seems like somewhere I seen an after market thingy you can buy and rivet into place. Still just considering new gears though, still have some time before the good snow gets here to weigh options.

 

[73GOLIATH]

hi
i run the 10.4 clutch on my 06 m7 all you have to do is dimple the foot rest on the inside of it for clearance and you can change belts with no problem also i noticed a improvement in the bottom end power not much at the top but i have done the 10.4 on a few of the m7's 05 and 06 with no problems
hope this helps

 

[wart]

It seems that there has been a lot of good comments now and in the past about doing the 10.4. I think it could help, makes total sense anyway. Gearing will be my next step after the clutch.

Thanks Everybody!!

 

[Barrett]

just an FYI for those who may not fully understand what doing the clutch mod/or 10.4 sheaves acomplishes.
with the mod, or the10.4" the clutches will start out in a lower gear ratio, and since a longer belt is used, when the primary is fully shifted out, the belt will not be as far into overdrive as with the shorter belt. Cats original 10" DD clutches were set up with about 25% OD at full shift, something that is ALMOST IMPOSSIBLE to acheive. We all know that 1:1 is the most efficient, so acheiving the most useable shift in the clutches without being in OD is what we are after. Using a 10.4" and 046 is an improvement on the original 10", and a cut 10.4" is even better. this acheives more useable shift in the clutches, which makes the clutching more responsive to changes, and fine tuning easier, as well as increasing belt to sheave contact area - which will reduce slippage, and therefore clutch/belt temps. I am a flatlander, but this is what you mountain dudes need.

 

[vdo1948]

If you put the BD adjuster on, the easiest way to change the belt is simply pull the secondary clutch. Put the 10.4 on my '05. Did dimple the 45* bracket that hides the connector for the speedo sensor just for clearance. Bought the belly pan tub but haven't even put it on yet. Yes it a pain to get the belt off if you leave the clutch on, but a piece of cake if you pull the clutch.

 

[Luke The Drifter]

I put on a Supreme Tool 11" secondary and its one of the best mods I've done to my M7. Very easy to adjust and once I got it tuned right, it hauls a$$! Just another option.

 

[wart]

So to confirm shaving the sheaves are the best route to go. Is the correct amount .055" from each sheave? If this is better and I'm thinking would cost less than new sheaves it might be the ticket. Is there a special shop that does this or should any machine shop be able to accomplish this?

THANKS!!

 

[Barrett]

So to confirm shaving the sheaves are the best route to go. Is the correct amount .055" from each sheave? If this is better and I'm thinking would cost less than new sheaves it might be the ticket. Is there a special shop that does this or should any machine shop be able to accomplish this?

THANKS!!

any competant machine shop should be able to do it. yes .055" from each sheave will work. It did for me. Some guys cut less, some more, it doesnt matter, what does matter is that you are able to get the sheaves close enough together to acheive proper belt deflection with the longer belt.
ps you will need to remove shims from behind the secondary to get correct alignment. with the cut clutch you need to remove .055 from behind the clutch, compared to the cat align bar.

 

[wart]

If I just go with a new 10.4 clutch instead of maching mine will I still have to adjust shims behind the clutch?