Main Sleeve Gear

I've stumbled across a sleeve gear, presumambly 06-5954. It has no markings. Current sleeve gear sold by AN carries the "AH" marking.
Question, did NV mark sleeve gears made at the time by "AH"?

Any idea why the new ones are marked AH? It can't be a change to the tooth form, as the layshaft 4th gear is still the same (06-1058). Nevertheless, it carries the AH marking as well!

Strangely, there is no visible undercut at the dogs. Why is that:?

- Knut

mdt-son said:

Iæve stumpled across a sleeve gear, presumambly 06-5954. It has no markings.

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If it has no markings then it's unlikely to be 06-5954 as that was the 850 Mk3 sleeve gear, the final version of Commando sleeve gear marked AH3 with an internal bush-retaining circlip groove at each end.

mdt-son said:

Any idea why the new ones are marked AH?

Click to expand...

It isn't a new marking.

mdt-son said:

It can't be a change to the tooth form, as the layshaft 4th gear is still the same (06-1058). Nevertheless, it carries the AH marking as well!

Click to expand...

'AH' on layshaft 4th is a recent AN marking.
An original 06-1058 layshaft 4th would be marked with a '6' or a '9'.

Thank you Les. I'm enclosing a photo of the sleeve gear 06-5954 made by AN. I'd like to see a photo of the markings on a corresponding genuine NV sleeve gear!

- Knut

Edit:
Here is another unusual gear to me, a NOS layshaft gear claimed to be (06-1058) and suitable for Commando models up to Mk2A.
It appears to be one of many counterfeit gears flogged on Fleebay.

The second photo shows the genuine marking of 06-1058. Apparently a change was made to the tooth form (?) and dimension.
It's important to know about these incompatible gears.

- Knut

mdt-son said:

I'd like to see a photo of the marking on a corresponding genuine NV sleeve gear!

Click to expand...

The best I can do is a blow-up from one of my old gearbox pictures.


This is the single circlip (Mk2/2A) 06-4991.

mdt-son said:

Here is another unusual gear (to me), a sleeve gear claimed to be NOS and suitable for Commando models up to Mk2A, marked "AH" only, no "6" or "9".

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"A4H108" isn't 'AH'


All three sleeve gears 06-1057, 06-4991 and 06-5954 are basically the same. It's the addition of the single circlip groove (06-4991), then the second groove (06-5954) that appears to have resulted in the change of part number and all are compatible with the 06-1058 layshaft gear but the first Commando sleeve gear 040422 is not compatible due to the different gear dimension.

mdt-son said:

An indication a change was made to the tooth form beginning with the Mk3 model.

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The Mk3 layshaft 4th is the same 06-1058 gear. The only change of tooth form I'm aware of was at 128646 in late '68 - early '69.

(Another) Original 06-1058 layshaft 4th.:

The Mk3 sleeve gear 06-5954 replaces the previous 06-1057* (not 04-0422 without layshaft 4th also being changed due to the dimensional difference) so there couldn't have been a change of Mk3 sleeve/layshaft 4th. tooth form after 06-1057.

*(Therefore also 06-4991)

L.A.B. said:

The Mk3 sleeve gear 06-5954 replaces the previous 06-1057* (not 04-0422 without layshaft 4th also being changed due to the dimensional difference) so there couldn't have been a change of Mk3 sleeve/layshaft 4th. tooth form after 06-1057.
*(Therefore also 06-4991)

Click to expand...

You have convinced me. Altering tooth form of the layshaft 4th (and therefore, of the sleeve gear) would have been a fairly radical change, prompting a new part number.

- Knut

mdt-son said:

You have convinced me. Altering tooth form of the layshaft 4th (and therefore, of the sleeve gear) would have been a fairly radical change, prompting a new part number.

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Yes.

Pre-Commando (Wideline, Slimline, etc. list) but also applies to Commandos up to 128646 that AN has overlooked.

"36 (only if replaced singly)
LAYSHAFT 4TH GEAR 18T
part-no: 04.0284"

"36A (paired with 06.5954)
LAYSHAFT 4TH GEAR 18T
part-no: 06.1058"]

Oh, and I almost forgot...

mdt-son said:

Strangely, there is no visible undercut at the dogs. Why is that:?

Click to expand...

Well, the dogs of the 06-4991 sleeve gear are undercut, therefore, the 06-1057 and 06-5954 dogs should be.