Mk3 Inner Chaincase Support

EXACTLY SO.

plj850 said:

Hi I guess confusion arises because spacing the the support stud away from the cradle would appear that (without having all the parts in front of me) is no different from supporting the stud away from the chaincase,

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Yes it may appear that way unless you've done it, but that is not what is actually being achieved by placing the washers between the support hexagon and the cradle, as the number or thickness of the washers has no effect whatsoever on the final positioning of the chaincase.

And at this point I would like to refer everyone to what it says in the MkIII factory workshop manual Section C:

Quote: "Make sure the central adjustable support stud is fitted behind the cover with the abutment nut slackened off, in readiness for adjustment after the outrigger nuts are tightened. (See Fig C45)"

Fig. C45



Note that it says: "adjustable support stud"

And no mention of any shimming? And once the outrigger nuts are tightened (which according to the manual instructions is done before adjustment) then none can be fitted behind the chaincase.


It's just a simple job of fitting the inner cover over the support stud, and then tightening the nuts on each side of it to secure it in position!

Attempting to shim the MkIII case would just be making an easy job difficult.

The reason that it may be necessary to add a number of extra washers (or shims, if you like?) behind the support stud appears to be because neither of the threaded ends of the stud either side of the hexagonal section are an ideal length, as the shorter inner end of the support stud which passes through the cradle appears to be slightly too long and the much longer end that passes through the case isn't quite long enough, so the support stud is merely spaced away from the cradle slightly to compensate for the discrepancy.

Thanks for stating that so clearly L.A.B.

I'm afraid that I had pretty well given up on the thread. I know what I do and it works for me. Apparently I've been following the manual which is reassuring. It really is far more logical to offer up the case over the five (four at the front) studs and ensure that everything is centred before running out the support nut.

As you say, those that've done it know why (and those with earlier models are just jealous ) Well, we've got to have some compensations for running the slow, heavy old Mk111s.

My in-built parts book error filter had meant that I'd never even noticed those inconsistencies.

I have no way to go back and check 2 of the 4 that I've done, but it could be a case of having received the wrong parts twice, and dealing with it as best i could. The case was such that there was insuficient threaded section to accommodate a nut for adjustment purposes behind the chaincase, or i would have done so.

Help and advice with the next bit please.

When I do a dummy fit the gearbox shaft isn't centered in the hole of the chaincase.
I can take up most of this misalignement with moving the chaincase up and forward before tightening the 4 bolts.
Then I assume the gearbox has to be loosened and moved to get better centering of the gearbox shaft ????

As the chaincase ends up being heavy when it's complete, and is only positioned by 4 bolts, a pillar bolt and a seal, what stops it from sagging and wearing away the seal on one side ?

Then how do you fellows make sure the gearbox shaft is parrallel with the crankshaft ????

Graeme.

Basically there is very little room for adjustment, as the MkIII gearbox is fixed.

I've never known the chaincase to sag, probably because it is clamped by five studs?

79x100 said:

Thanks for stating that so clearly L.A.B.

I'm afraid that I had pretty well given up on the thread. I know what I do and it works for me. Apparently I've been following the manual which is reassuring. It really is far more logical to offer up the case over the five (four at the front) studs and ensure that everything is centred before running out the support nut.

As you say, those that've done it know why (and those with earlier models are just jealous ) Well, we've got to have some compensations for running the slow, heavy old Mk111s.

My in-built parts book error filter had meant that I'd never even noticed those inconsistencies.

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Im not jealous I get more oppurtunities for fiddling about and adjusting