I am still not happy with my Commando clutch. Took it all to bits and cleaned out, no dramas but its fitted with Surflex bonded plates NOT bronze ones. Fortunately I have a complete brand new Norvil belt drive kit for my 650SS rebuild, so I checked the plates in that kit , sure enough exactly the same Surflex, but with only 4 friction plates and a thicker top plate. New plates measure ~ 3.6 - 3.65 mm, old ones measure ~ 3.2 - 3.3 mm, so not sure when the wear limit is reached, but seened to have plenty of 'meat' left, however if someone can assist with a wear spec that would be very helpful. Same diaphragm spring but the new one (in a genuine Norton Villers bag) was constructed differently. So I took a punt and fitted a new spring with all the old bits. Wow what a difference, magic action easy, to select neutral when stationary (a first, I used to have to knock it into neutral white rolling) and no drag. So I took the old girl for a thrash and went like the proverbial clappers, no slip or drag, everything was fine until I got back home and in the drive and she was dragging again. Grrrr, checked all the free play etc, nothing had slipped / moved, so not sure whatâs causing this. 200 cc TQF in the case, primary chain adjustment fine and in spec, no EP90 leaking into case either. So any advice would be appreciated.
Rgds Steve
Alright Steve, Try checkin…
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Thanks Simon, Sorry I forg…
Thanks Simon,
Sorry I forgot to include that the clutch centre is new-ish and I checked for notching on strip down and everything is fine. I have a clutch pushrod seal retrofit and the o-ring is in good condition definately working OK.
I will however chech the 'stack' height and maybe someone will give me some wear tollerance limits on the Surflex plates.
Bearing is pretty new and tested OK.
Anyway big ride to the Barossa valley AM tomorrow so we will see!
Rgds Steve
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Alright Steve,
Try checking the steel plates are flat to within a 0.001'' at least, and check the frictionplates are flat too.Also look for notches in the hub slots where the plates move, and make sure the plates are free to move. I've found the plate 'stack' should be so the top of the pressure plate is level with the lower surface of the circlip groove.If your getting drag then there's not enough clearance between the plates. Make sure the clutch bearing issound.Adjust the pushrod clearance to a minimum, but make sure there is stillclearance at the pressure plate adjuster hot or cold, likewise with the cable.
I get oil contamination on my Mk3's plates after several thousand miles which can cause slip and drag, after a clean everything is ok. I alsouse AT fluid, which is an improvement over thicker oil.
The contamination is in the form of very sticky oil, which looks like it's been overheated, and is possibly gearbox oil travelling along the pushrod shaft or the ATF. Iuse a radial roller bearing (RGM)between the spring and pressure plate, sothere's no seal on the pushrod.Which ever oil it is it can't cope living between the clutch plates.
I've considered using something like 5w/30 synthetic engine oil, sounds crazy but as the bronze plates can are not dependent on oil for grip, then as long as the oil is dispersed from between the plates there should be no slip. The synthetic oil I assume would retain its viscosity and not contaminate the plates. No big deal if it dosen't work, as a clean will resore things as they were.
An American member suggested using ATFin the geabox as he considersthe oils properties would withstand theforcesbetween the gears. Any body brave/rich enough to try this?
Hope you get it sorted,
Simon.