Mk3 changes from 74 models

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From some reading this am, it appears that for the MK3, the gearbox shell was made thicker in some crack prone areas.

Glen
 
worntorn said:
Check valve on pressure side of pump.
Then there is the other oil plumbing change Jim Comstock described today. I haven't gotten my head around that, need to reread the thread.
One change that was a retrograde step was going back to the rh4 head from the rh 10 of 1974.
Click to expand...

I've got two MK 3's and both have RH10's. We're the heads fitted to different models, was it random or changed for certain batches? Len?
 
Len, from my reading here and elsewhere, the 74s received the RH 10 heads, but it is quite possible that some MK3 s did as well.
Or the original RH 4 heads on your bikes may have cracked and been replaced by RH 10 heads?
Do your MK3s happen to be early number bikes?

Glen
 
worntorn said:
From some reading this am, it appears that for the MK3, the gearbox shell was made thicker in some crack prone areas.

Glen
Click to expand...

I have many 73 and 74 850 tranny's that have the "later" beefed up cases...and also have the neutral switch boss.
Only the LH shift MKIII have the shorter/machined quadrant boss on these later cases.
 
Cush rear hub was added for the MK3.
The previous Commando hub with plastic inserts thought to be ineffective as a cushion for the drive line.

Glen
 
worntorn said:
Cush rear hub was added for the MK3.
The previous Commando hub with plastic inserts thought to be ineffective as a cushion for the drive line.

Glen
Click to expand...

I think you meant a better cush hub.?

'74...
Mk3 changes from 74 models
 
Hi worntorn.
Nylon, I suspect, in the version shown above.
Ta.
 
That version shown just above is also going to have other issues. ?

Since the 2 central (axle) fittings in the hub and brake drum won't actually meet - unless there is an additional spacer not shown - when
its all fitted and bolted together, the drum paddles will be pulled HARD into the hub.

And the cushion action will be metal-to-metal on the paddle ends = diabolical, to say the least....

???

The fitting in the drum should have a projection that juts out, to meet the bearing centre in the hub.
 
The consensus seems to be that this type of drive offered virtually nil cush. I believe that is why Madass has come up with one that does.

Glen
 
If some cush is good, more cush must be gooder ?


I've got an old Enfield, that had the 3 big paddles and 6 quite large rubber/plastic blocks.
To see the sprocket working the cush and the hub not moving is quite unnerving.

The idea was only to take the shock loading out of the gears on gearchanges,
and the Commando one was quite effective at that.
Far fewer cases of gears loosing their teeth

??
 
Rohan said:
That version shown just above is also going to have other issues. ?

Since the 2 central (axle) fittings in the hub and brake drum won't actually meet - unless there is an additional spacer not shown - when
its all fitted and bolted together, the drum paddles will be pulled HARD into the hub.

And the cushion action will be metal-to-metal on the paddle ends = diabolical, to say the least....

???

The fitting in the drum should have a projection that juts out, to meet the bearing centre in the hub.
Click to expand...

It was missing for a bit.
 
Madass' setup sure looks good. If I had a rear disc brake I'd be more concerned. I suspect it will work fine though. They're just another rubber consumable like tires and isolastics. If I had the skillset I'd copy Ludwigs design.
 
Sorry for off topic..you can give a Mk2 a wee bit more (I hope) cush by replacing the 3 larger nylon blocks by rubber Mk3 ones, cut to size.
 
A hook was added to the rear loop to assist with rear caliper maintenance
 
Thanks to Peterjoe for another little MK3 transmission tidbit-
" So I was just getting ready to order a new Mark III type sleeve gear which has a circlip that prevents the bearings from coming out. "

Glen
 
From recent posts on the forum, it appears the MK3 cam bushings are an uprated design vs earlier engines.

Glen
 
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