Moss Gearbox Overhaul

Technical advice Q&A

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Fastrack58
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#1 Moss Gearbox Overhaul

Post by Fastrack58 » Tue Jul 16, 2013 7:54 pm

Hi there,

I'm new to the club, new to E Type ownership and this is my first posting so please forgive me if I'm asking something that has already been covered many times. I've tried a search on my question and a definitive answer was not obvious in the results.

I need to have my Moss gearbox overhauled and was wondering who are considered to be masters of this art? I live in the midlands but don't mind traveling to acheive the desired outcome. I seem to recall that Practical Classics featured Hardys Engineering to overhaul a Moss Gearbox on a Jensen some years ago. Any advice from your experiences?


This bit is optional to read - Merely to set the scene for what I have and what I'm doing:

I have recently bought a LHD matching numbers 1963 FHC in it's original colour of Opalescent Silver Blue with a Blue interior. I acquired it from a friend who bought one too many cars and having gone to the trouble of importing it sold it to me at cost after allowing me to inspect it.

It was missing it's gearbox, flywheel and Starter Motor. I've since acquired a Moss Gearbox of unknown quality and would rather have it looked over rather than just fit it only to find it's a dog. The car is largely complete otherwise and very rust free (oh and it satisfies a very long held dream to own an E Type!).

Thanks in advance for you help and advice,

David

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tim wood
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#2

Post by tim wood » Tue Jul 16, 2013 10:14 pm

hi, the topic has been covered many times, including by me. I researched quite a bit and opted for Klassic Transmissions in Birmingham. They have a web page which is quite useful.

in the end I had the opportunity to pick up a rebuilt box ( all synchro - which is right for my car) so never went ahead.

I did visit the workshop run by a father and son i think. absolutely full of gearboxes including many jaguar. the finished jobs looked outwardly good.

I have no connection with this company. just my input.

good luck
TIM

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PeterCrespin
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#3 Re: Moss Gearbox Overhaul

Post by PeterCrespin » Wed Jul 17, 2013 12:47 am

Fastrack58 wrote: It was missing it's gearbox, flywheel and Starter Motor. I've since acquired a Moss Gearbox of unknown quality and would rather have it looked over rather than just fit it only to find it's a dog. Thanks in advance for you help and advice,

David
Welcome aboard.

Just be certain that whatever bell housing you have, or buy, you get a matching flywheel and starter, or you will become more familiar with E-type engine removal than you may wish.

Being a Moss, it will take a 3.4/3.8 or 4.2 bell housing so just make sure you get the correct flywheel. The starter is slightly easier because you can buy a modern hi-torque one for not much more than the price of a rebuilt original, but even so it's best to buy the three items from the same car if you can. Your car will have a separate solenoid and wiring for the early Bendix inertia starter anyhow, so you may as well stick to that if you're keeping to the original Moss box as well.

Having assembled your collection of parts, be sure to bolt everything up to the back of the engine on the workshop floor and check the starter cranks and disengages exactly as it should. You don't want to find there's a problem after you put the engine and gearbox in the car. Fitting it all from underneath is generally thought to be the best option for DIY work.

Pete Crespin
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas

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38E
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#4

Post by 38E » Wed Jul 17, 2013 3:27 am

Be aware that the 3.8 flywheel is quite different and a lot lighter than later ones. Here's a 3.8 E-Type unit, on the right.

Image

The Moss box is fairly simple to work on. I rebuilt my own using new main bearings and a couple of minor parts from a donor box. A lot can be told by merely taking off the top and looking inside.

The Moss box is said to absorb much less power than the later all synchro box. If so, one consolation for having one. :D
Clive, 1962 Coupe 860320
(sold)

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Fastrack58
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#5

Post by Fastrack58 » Wed Jul 17, 2013 8:03 am

Thanks for your help so far. Thankfully the EB---JS gearbox came with it's bell housing still attched and covered in filth. The Starter Motor Issue is sorted too as I was able to pick up a NOS Lucas Bendix Starter (It was actually still in it's Lucas Box and had a Lucas Warranty card inside - somewhat yellowed with age though!).


The flywheel pictures posted by Clive concern me though as from memory I think I may have been supplied with the one on the left by a well known Jaguar supplies business. I say from memory as I dropped it off at the machine shop on Monday for a skim. I will ask him to hold off until I'm certain of what i've got and what I need.

I went to the trouble of assessing whether the ring gear was integral (it was) and counted the teeth (104). So, it may be I've been sold a Mk2 2.4, 3.4, 3.8, 240 or 340 flywheel....

Clive, what was the other flywheel in your picture?

Thanks again,

David

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PeterCrespin
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#6

Post by PeterCrespin » Wed Jul 17, 2013 12:57 pm

104 teeth should be fine. You should see that the teeth have been burred on the gearbox side from engagement with a 3.8 Bendix inertia starter, whereas the 4.2 pre-engaged starter burrs the flywheel teeth from the engine side.

Not every 3.8 E had that light flywheel AFAIK. I've got one the same, but at one time they were offered as an option. The light part number is listed somewhere.
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas

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38E
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#7

Post by 38E » Wed Jul 17, 2013 1:14 pm

Fastrack58 wrote:
Clive, what was the other flywheel in your picture?

Thanks again,

David
I'm not certain what it is but I believe it to be from a '61 3.8L XK150. The E-type unit is from about a '62 car and weighs 20lbs, 5lbs less than the other.

Yes, confirm the proper number of teeth. 104 rings a bell but I know you can get into all sorts of trouble by having mis-matched ring gears and starters.

You were lucky to find a NOS starter. I don't think there's anything wrong with the original units if they are working properly. Here in S. Ontario we have a local ex-Lucas technician who rebuilt mine for a very reasonable price and it now performs very well.
Clive, 1962 Coupe 860320
(sold)

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Fastrack58
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#8

Post by Fastrack58 » Wed Jul 17, 2013 5:02 pm

Well, I got to my local machine shop at lunchtime to stop him from skimming the flywheel until I'm happy with whether I've got the correct part.

Unfortunately he'd just finished it! It looks great though. Oh well. I can confirm that the ring gear has it's lead in chamfer on the gearbox side but that it weighs in at about 25 - 26 lbs.

So, I presume I could lighten it if necessary by having some of the rim on the back face machined off if I was aiming for a 20lb flywheel.

I'm open to all guidance on this from the forum. Unfortunately if one doesn't have an old part to compare it can be quite difficult to know what your buying.

Thanks for your help,

David

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Fastrack58
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#9

Post by Fastrack58 » Wed Jul 17, 2013 5:44 pm

Now it's all clean of muck and surface rust I've just found the part number stamped into the back face. C 23328 - certainly not an E Type number...

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38E
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#10

Post by 38E » Wed Jul 17, 2013 6:16 pm

There should also be an engine number on there somewhere which may help identify it.

The E-Type Parts Catalog lists just two flywheels for the 3.8:-

C14921, FLYWHEEL (LIGHTENED) STANDARD FITMENT

C20310, FLYWHEEL (LIGHTENED) COMPETITION CARS ONLY.
Clive, 1962 Coupe 860320
(sold)

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Fastrack58
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#11

Post by Fastrack58 » Thu Jul 18, 2013 7:12 am

Thanks Clive,

I'd seen the other set of numbers on the circumference of the flywheel but not understood their significance. They are LC---- which my reference book puts this component as a Mk2 Saloon 3.8 flywheel. I'm still getting familiar with how items were numbered and referenced 'The Jaguar way'. I've certainly never experienced the engine number being stamped into the flywheel before. It turns out it's very useful! (so long as you know it's there)

How frustrating... :(

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38E
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#12

Post by 38E » Thu Jul 18, 2013 2:21 pm

Fastrack58 wrote:Thanks Clive,

I've certainly never experienced the engine number being stamped into the flywheel before. It turns out it's very useful! (so long as you know it's there)
Yep. Same thing with the crankshafts, in my experience and maybe a couple of other parts.

Possibly when they were balanced at the factory.
Clive, 1962 Coupe 860320
(sold)

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