9.1 Failure to Adjust following Rebuild.

Date: Mon, 26 Feb 1996 07:25:26 -0800 (PST)
From: Brian Pankow

Hello All,
I have a puzzler to start of the week.

The bike in question is a '75. I was doing some work on it over the weekend (new pipes and mufflers), and thought I'd do the conversion to ATF in the primary. Keep in mind the clutch was working fairly well with what I thought might have been a little slip at times. I dismantled the clutch to find a previous owner had made the conversion from five bronze plates to three bronze and two fiber. As per "Norton Service Notes" I cleaned the plates in petrol and put everything back together. I added ATF to the primary case and set about adjusting the clutch. Now here is the puzzle. I can not get the clutch to adjust so it will release! I've even had the adjuster bolt to pushrod clearance to as close to zero as I dare and almost not cable freeplay. Under these conditions I can just get it to work - sometimes. Plates are fine, push rod is ok, etc. Every thing looks good. The thing will just not release enought so I can change gears. It is as if the clutch takes up more space than it did before. The only answer I can come up with is that I shouldn't have washed the fiber plates. Can they swell? This could be an answer.

Does anyone out there have an answer or cure. Should I replace the fiber plates I washed? I've had the thing apart four times in two days and it's making me nuts.

Brian

Date: Mon, 26 Feb 1996 15:51:24 -0800
From: Thomas H. Allen

Sometimes the release arm that pushes on the ball that pushes on the pushrod that pushes on the adjuster screw will slip out of place. Take the trans. inspection cover off and look. If that's not it you probably didn't get it clean enough the first time. I've found that they tend to drag when cleaned with only petrol or solvent. Maybe something about the way it reacts with ATF. Having cleaned dozens of Commando clutches I have come up with a combintion that appears to work well (people don't come back and complain, anyway).

  1. Clean the plates, clutch basket, inside of primary housing, etc. with solevnt. Petrol is too dangerous.
  2. Cean the plates again THOROUGHLY with 1.1.1 Triclorethane (brake parts cleaner).
  3. Poke out the drain holes (3 or 4) at the back circumfrence of the basket (holes go through to the sprocket teeth) with a bit of wire.
  4. Spray brake parts cleaner through these holes.
  5. Clean the inside of the basket with same.
  6. Reassemble using silicone sealer on the bottom half of the o-ring.
  7. Don't fill with oil till the silicone sets up. Over night if you have the patience.
  8. Use Valvoline Ford-type ATF (bronze plates) or Dexron (fiber plates and combination).
  9. Use 7 oz of oil only, no more. You want oil even with the sight plug when the machine is leaning left at 15 deg, not straight up as on the center stand.
Also, take all the plates and put them on a glass counter top and check for warpage. You don't want them to act like a bunch of wavy washers. They'll never disengage if they're warped. With fiber plates you may find that the clutch tends to drag slightly until it warms up a little. The bronze plates won't drag if you clean them thououghly but they will slip after you ride around town for a few hundred miles. If you're really ambitious you can cut radial groves in the bronze plates and bead blast the plain plates. Also check the splines on the hub. The clutch plates dig into these after 10-15 K miles and the plates tend to center on the resulting groves and fail to releas properly. The current replacement hubs are harder than the originals but still not hard enough.

Tom Allen
75 Commando, 66 Atlas, 65 Matchless G-15 CSR, 60 Matchless G-80CS, Assorted
Kraut & Rice

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9.2 Hard to Operate.

Date: Tue, 21 May 1996 19:01:10 -0400
From: Gary Slabaugh

In a message dated 96-05-21 13:47:29 EDT, you write:
>The only real complaint I've got about Norton clutches is the force
>required to pull in the lever. I've been through the entire linkage
>fine tuning it and its much better than it ever was, but still much
>stiffer than any Jap or American bike I've ridden. No wonder my left
>wrist is larger than my right by the end of
>the season! ; )

I have found that the trick to setting up Norton clutches for a light action at the lever is to adjust the overall thickness of the combined steel/friction clutch pack so the diaphragm plate is pre-loaded to the point that only a small amount of lever travel will put it over center. Friction plates of different manufacture and mileage will vary in thickness. I recently installed new Barnett plates in my 71 Roadster and obtained the properspacing with two steel plates installed first, than the first friction (four frictions total) and using a thin final steel plate from the later models that specify five total friction plates.

The result is two finger operation and it still doesn't slip at over ton speeds. If you get the clutch pack too thick you will probably have slippage problems.

I know some people get the spacing correct by using a combination of both bronze and fiber plates. I tried this once with two Barnetts/three bronze friction plates and thin final plate. The eventual result of all this was that the Barnett plates, having more friction, attempted to take up most of the load until all of the inner teeth were gone on the aluminum discs (the latest Barnetts have steel, not aluminum discs). This left me with with just three bronze plates on a Norton overloaded with touring gear 2K miles from home. Needless to say, I didn't pass many vehicles enroute home!

Gary

Date: Tue, 21 May 1996 23:01:44 -0400
From: Gary Slabaugh

ooops...

I checked my maint. notes after sending the earlier post about modifying a Commando clutch into a two finger operation and I see that I actually installed one additional steel plate not two. The friction plate kit is the latest Barnett Kevlar unit. The assembly sequence is as follows:

Basket > steel > friction > steel > friction > steel > friction > steel > friction > thin press. plate > diaphragm

Does this make sense?

Gary

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