Do I need new clutch plates?

rmak · Mar 17, 2009

Noob question alert! I noticed last year before I put my new to me 74 Commando up for the winter that the engine raced when I shifted into 4th gear. It would only do this if I shifted on the quick side under power. If I shifted slowly and let off the revs the clutch seemed to catch immediately. I didn't sense any slippage in other gears.
I adjusted the clutch nut according to the manual last fall, but with my early spring rides the problem still exists. I just removed the primary cover for the first time, and the oil didn't appear to have too much clutch material like I think would be in evidence if there was a lot of slippage.
In a conversation a while back with one of you guys from the forum I was told I could remove and clean the clutch plates, but with plates at $52.00 on ebay, would it be better to just replace and start fresh? I guess I would also need to pick up a clutch removal tool as well. Any advice, wisdom or tips for me before I tackle this issue? Thanks,
Rich

Hortons Norton · Mar 17, 2009

I would first buy the clutch tool and see if cleaning the plates helps. You will need the tool anyway, Then maybe move on if that won't help, I have seen guys even rough up the plates with a little fine sandpaper too. Worth a shot at the very least.

Jeandr · Mar 17, 2009

Cheap tool

He are a couple of pictures of my clutch removal tool. I went fancy with a round plate and a bearing, but basicay, it is a PVC pipe cap a metal plate to support the tension and an ½" x 20 bolt and nut. Making one should not cost more than a few dollars and take very little time.

L.A.B. · Mar 17, 2009

If your Commando still has it's original bronze friction plates, they probably just need to be removed and cleaned, as the bronze plates practically never wear out.
Gearbox oil has been known to migrate along the pushrod tunnel and contaminate the plates which causes them to slip, so fitting the Dynodave Commando clutch rod seal can be a worthwhile modification. http://atlanticgreen.com/index.php?opti ... r&Itemid=8

You can either buy or make a suitable clutch spring compressor tool, just don't try to do the job without one!

Hortons Norton · Mar 17, 2009

Very nice! I wish I had made mine instead of buying it. There is a sense of pride in making ones own tools. I have made a few of my own, I kinda like those types of projects. That's a nice one Jeandr.

Commando74 · Mar 17, 2009

just made the tool to pull the engine sprocket. Don't think I saved any money but it was more gratifying when I heard the sprocket "pop" loose.
Eric

Cookie · Mar 17, 2009

Very interesting. I have to make one soon myself, I would not have thought of using two materials.

Jeandr · Mar 17, 2009

Cookie said:
Very interesting. I have to make one soon myself, I would not have thought of using two materials.

That's 3 different materials

Aluminum plate, PVC end cap and steel bolt

Jean

Cookie · Mar 17, 2009

Composite it is. I didn't think of the bolt and nut. This is why you sell us airplanes and railway cars now.

RennieK · Mar 17, 2009

I think it was Ron who made one out of an electrical box available at any hardware store. I made one out of a sink drain that works well. I think I used to use the transmission fixing bolt with some spacers for the rest.

batrider · Mar 18, 2009

Chicken of the Sea tuna can works best! Made mine in 1973!

For roughing up the clutch plates the concrete garage floor works best.

The cleaning should fix it right up.

Russ

rmak · Mar 18, 2009

If someone could give me some info on the best way to clean the plates and what part of the clutch to rough up with what kind of sandpaper I would appreciate it. Did a search under "cleaning clutch plates" and got 23 pages about everything but clutches. Apologies if this subject is too trite for this forum.

RennieK · Mar 18, 2009

It's been a while but I likely used old used emery cloth of 400 grit. You only want to de-glaze them (take the sheen off) and leave a dull finish on them.

Always sand across the plate from inside to outside and not around in a circle which is the easiest but is the same type of friction they receive under use and it won't help. Don't create any low spots, do an even job across the whole plate. Check the steel plates for pitting and lightly rough them up too if they appear glazed or pitted. You don't want to scratch them just give them a dull finish.

rmak · Apr 1, 2009

Sorry to resurrect this thread. I just wanted to mention to other new members that when you use the search feature, just use one word. I'd been trying to sort using "clutch plates" "slipping clutch" "cleaning plates" etc. without success. Today I just searched "clutch" and got a lot of useful hits.

RennieK · Apr 1, 2009

Cool, I'll have to try that next time. I've had futile results when trying to search.

Another thing you can do when the splines are worn like yours is to put 2 plates the same together (put a steel one in 1st.). This moves the spline area over one notch. If your plates aren't getting an oil bath (which causes most the problems) it's surprising how well this works even with the 2 less surfaces that result from this practice.

chris perfect · Apr 1, 2009

Interesting reading this. Any welder can make these up for a couple of bob. I sold my Mk 3 in 1980 and I think I still have ny made up extractor somewhere built with a small G clamp and some welded plates. I will see if I can find it and offer it on here. Free of course.
While I'm at it did anyone ever find the cure for duff starter motors on Mk III s ?

rmak · Apr 4, 2009

I just ordered a clutch rod seal and a clutch compression/extractor. Since this is my first time disassembling the clutch I wasn't sure of the pressures involved. I had visions of being killed not only with the nut, but with chunks of my poorly built tool, so I chickened out of making one. I'll post a record of cleaning plates and installing seal for other new Commando riders when the job is done.

L.A.B. · Apr 4, 2009

chris perfect said:
While I'm at it did anyone ever find the cure for duff starter motors on Mk III s ?

Fitting a battery that has enough CCA's to actually power the starter, and a set of heavier gauge starter leads capable of handling those starting Amps, works wonders!

Fitting a four brush kit, and/or four field coils to the starter can also prove to be worthwhile modifications, although I found that the four brush kit on its own along with an AGM battery and heavier leads was all that was required in order for the starter to be able to turn my MkIII's engine over quite easly.

Do I need new clutch plates?

rmak

Hortons Norton

Jeandr

L.A.B.

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Hortons Norton

Commando74

Cookie

Jeandr

Cookie

RennieK

batrider

rmak

RennieK

rmak

RennieK

chris perfect

rmak

L.A.B.

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