Pivot jaw assembly - Moss Gearbox

[fredmec00@hotmail.com]

Gurus!

I am working on a moss gearbox for an E-type S1. It is
missing the bell housing and the pivot jaw assembly for the
shifter.

I have located this assembly, pictures below. Is it the
correct one? or perhaps is the one for the later S2 (sll-
syncro)? Looking at the parts catalogs, drawings were pretty
similar!

http://i1307.photobucket.com/albums/s59 ... 0/P1260339_
zpsa5cvs000.jpg

http://i1307.photobucket.com/albums/s59 ... 0/P1260342_
zpsba9eth44.jpg

Need to know if I am buying the correct one. Any help will
be appreciated!

Thanks,
Fred

[PeterCrespin]

Same answer as on Jag-lovers

[fredmec00@hotmail.com]

PICTURES VIA TINYURL!

http://tinyurl.com/o4ks8h9
http://tinyurl.com/or8lsq8

[abowie]

This is the Moss box from my '64 OTS

[fredmec00@hotmail.com]

Great pictures Andrew. Would you know if the assembly is interchangeable with the All-Syncro gearbox?

Reason why I ask is that, the pivot jaw assembly in the car (all-Syncro) could be used in the moss.

Any hint there will be welcome!

Cheers,
Fred

[abowie]

I don't think they are the same but I don't know enough about it to know what the differences are.
I believe it is possible to use the Moss one in a later box but this requires modification.

[PeterCrespin]

I've got both in the workshop so will check when it's light here. Not all 4-synchro ones are the same.

[MarekH]

Dear Fred,

There are three things you'll need to look at:-

1/ Not all all-syncho items will be the same. If you look at the way the rods are engaged, then, the long top boxes (xj6?) use an additional rod between the pivot assembly and the three selector rods. This means that the bottom of the pivot assembly uses its circumference as a contact point and will too fat to fit into directly without being filed down into a a wedge shape. By contrast, the short top boxes (s type, e type) engage the selector rods directly, which means that the pivot has to fit the selector rods, not an extension piece. Accordingly, to accommodate the throw from 3/4th to reverse, its bottom piece is more wedge shaped as it has to swing from left to right.

2/ As the gear lever sits further forward or back with a short or long top, I'd expect the angle of the gear lever to bottom of pivot be subtly different, but this is relatively trivial.

3/ Whilst the height the all-synchro pivots sit at is the same, you'd need to look at whether the same elements of geometry for the Moss box apply to see whether it still gives the same operating clearances required.

kind regards
Marek

[fredmec00@hotmail.com]

Thanks Marek/Andrew, I will buy the pivot jaw assembly from the moss. We included a bell housing and got a discount with Joe Chilbert. All for US$ 325.

No modification to the pivot jaw, it didn't look as straight forward as I initially though.

You all have a good weekend!
Fred

[PeterCrespin]

For the record I just measured Moss and short cover (i.e. E-type) 4-synchro selectors and as expected the Moss one is wider like the XJ 4-synchro that operates in a similar eyelet extension. My reading of it, without bothering to actually try swapping parts, is that the narrow short-top 4-synchro selector would operate in a Moss or long-top selector rod eyelet but the wider eyelet-type selector from a Moss or XJ 4-synchro would not work direct in the selector tods of a short top box. That's because it would inevitably try to move two rods simultaneously because the tab is wider than the cut-out in any of the three adjacent rods.

[fredmec00@hotmail.com]

Peter, I agree with you. It would probably be feasible to use the short all-synchro mechanism in the moss gearbox.

Out of curiosity I checked the pivot jaw assembly in a Series 2 (non-moss) and took a picture of it, below. The little arm does look thinner comparing to the moss version, circled in red.

http://tinyurl.com/laych6b

Any other things that are different between moss and all-synchro? Clutch fork, slave cylinder are the same, correct me if I am wrong.

Cheers,
Fred

[PeterCrespin]

Any other things that are different between moss and all-synchro? Clutch fork, slave cylinder are the same, correct me if I am wrong.

I don't think so, but to be sure one of us will have to look up part numbers...

[fredmec00@hotmail.com]

Yeap Peter, I checked the forks on 3.8 S1, 4.2 S1 and 4.2 S2.. they all have the same part numbers C9797.

Flywheel, starter should be the same, I counted the teeth and checked the part number for the started. My conclusion is that the bell housing in this 3.8 was machined to fit the all-synchro.

So in theory, with a new 3.8 bell housing the pivot jaw assembly, I am set to fit the old moss gearbox.

[PeterCrespin]

I am set to fit the old moss gearbox.

You must really love tractor transmissions...

Oscar Wilde called fox-hunting "The unspeakable in pursuit of the inedible." Looking at your long ID name, I might paraphrase your Moss box project as "The unpronounceable in pursuit of the unchangeable." Seems odd to remove an all-synchro upgrade and refit a 3-synchro Moss, unless I misunderstood. It is possible to do slick 1-2-1 changes but it's a bit of a black art and the gear whine is certainly 'atmospheric' I suppose. Good on you.

Be sure to check your bell, flywheel and starter function correctly before refitting the powertrain - they must all match in practice, not merely theory.

Pete

[fredmec00@hotmail.com]

Yeap Peter! Looking forward to see how I handle the tractor transmission... If I cannot manage, I will recondition the all-synchro and put it back in!