Moss gearbox servicing

[paydase]

Hi all,
I intend to service the Moss gearbox of my 3.8 FHC.
I sourced Redline MTL to do so.
I understand that draining should be done via a bottom plug and refilling via a plug on the LH side:



Before doing so, I would like to have a few confirmations and tips:
- what is the exact size of the hex plug on the side, is it metric or not? (same question for the drain plug) not to ruin the plugs if seized...
- is draining by gravity enough to empty the box from used oil?
- can the filling be done simply using a funnel and hose by gravity until oil reaches the level of the filler plug, and are new seals required for both plugs?
- and is there a possibility to later check the level with a dipstick that would be accessible from the top cover of the box? I see a dipstick mentioned on the angloparts sketch but without precise location:



I also see numerous plugs on the top cover pic but don't know what is their use:



Thx for your help

[lopena]

1) definitely not metric...nothing on your Jaguar is.
2) yes, gravity draining is sufficient.
3) yes...use a funnel or a squirt-bottle to refill with Redline MTL (an excellent choice).
4) yes, you must replace the two copper crush-washers (readily available from any auto parts store).
5) I never heard of a Moss gearbox dipstick...seems like overkill for something you only need to do once a year or so.

Good luck,
Alan
N.J.

[Heuer]

Serge

The box was developed in the 1930's and uses imperial nuts, bolts and plugs.
You can drain by gravity - leave overnight
Filling is best done by using an old gear oil bottle (with the long tube) as you can squeeze the oil in. A funnel and pipe would also work
No dipstick other than your finger pushed into the level hole (Jaguar refer to it as a 'level at side of casing')

The level and drain plugs are the same - part C799 and use washer C785 (specified as fibre in the SPC)
JB Sports are the best source of parts and spares (they specialise in Morgan's): https://jb-engineering.co.uk/?page_id=77

Redline MTL is superb but for some unknown reason it improves the Moss box over time so don't be too disappointed if is not a miracle cure! Can take weeks or months but it does work.

Edit: seem to have posted this at the same time as Alan but the info is the same other than the washer material!

[paydase]

Many thaks to both of you for your quick and very useful infos and tips!

[lopena]

Serge:

One last thing...since Redline MTL has a low viscosity it will exacerbate any gearbox leaks you may have. I’ve decided that the improvement in shifting performance is worth a few drops of oil on the garage floor.


Alan
N.J.

[paydase]

Thank you Alan,
I'm aware that the seals and my garage floor may disapprove but I am also willing to taste the improved smoothness brought to the Moss box :)
(although I am now used to the gymnastics of its gear changes ;))

[tinworm]

Dip stick on the previous model (XK150) as far as I know. If you look at the diagram supplied by the OP you can see the longer remote casting.

Barrie

[paydase]

Good point Barrie, that may be true.
I genuinely thought that the Moss box displayed by Angloparts was for an E-Type, as they advertise it on their website...
https://www.angloparts.com/en/catalogue ... -1961-1964

[paydase]

A few pictures from servicing.
Very straightforward:

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