Gearbox help

[Drdum]

Hi guys,
As I am restoring my 3.8 roadster, I have not figured out where my gearbox has come from. Gear Layout is as per a 4.2, but I could not find to which car does an FJ correspond to. Can you please help?
Code FJ4406
Production date 13.4.1965
Thanks!

[christopher storey]

It is almost certainly an EJ gearbox where the stamping of the E has gone over the lip of the gearbox lid, thus cutting off the _

I have not been able to trace any gearbox as an FJ series

[mgcjag]

You should have the number stamped on the aluminium lid.....and also on one of the small squarish lugs in the cast steel body top rear left side....Steve

[Joes66]

If its EJ then it could be a MK 10 or an E-type
You would have to look at the other numbers to find out which
Went through all this recently with the couple of boxes I got with my car
Joe

[christopher storey]

EJ boxes are all from E types. I'm afraid Joe's remark is inaccurate - all manual 4.2 mark 10s had JZN boxes

[Joes66]

Chris
I went into some detail looking at numbers for gearboxes and my research came up with mark X indeed having EJ gearboxes
Are you confusing the later 420G?
The EJ was used in the 4.2 Mk10, whereas the JZN and KZN were used
in the later 420G cars, when delivered with a manual gearboxes
Joe

[Series1 Stu]

Interesting. What gearbox did the manual 3.8 Mark X use?

Regards

[Joes66]

Stuart
I would guess along with the E type the 3.8 engine mark x cars also had EJ boxes
Information is scarce on this and I only found 3 references to Mark x boxes having EJ boxes fitted
And none of them official jaguar
I think its just the early mark x cars that may have got them but I can only go from what I found
And even though I found 3 references, they are only that
Can't be taken as gospel unless you found an authentic jaguar white paper on it
But like it seems jaguar fitted what they had at the time and then moved on to new parts as they came online
I also don't know if all Mark x had ej boxes or just some of them
I took three references as a good possibility that it was true
Joe

[mgcjag]

Jag gearbox info here... http://www.jag-lovers.org/xk-lovers/lib ... ation.html

[christopher storey]

I am getting a little tired of being contradicted by Joe66 on every occasion. Go and search the gearboxes listed on xkedata for all the models concerned . The EJ box ( which is a close ratio box, was fitted only to 4.2 litre E types( except that I believe a very few 3.8 litre cars may have had them in late 1964 when production overlapped ) . 420Gs had JZN and , towards the end, KZN boxes . Mark 10 4.2 had JZN . Mark 10 3.8 had JX although there may have been 1 or 2 late ones with GZN all-synchro . E type 3.8 had EB with a JS or JSO suffix except for a very few with CR suffix indicating a special close ratio box

And Steve: unfortunately the information in the USA link you have given is completely misleading : someone has just assumed that Mark 10 saloons and E types had the same boxes, which is absolute nonsense , because the mark 10 being 50% heavier required the much wider lower ratios

[Joes66]

Steve
The early mark 10 had a moss box with overdrive
This was changed to the all synchro when the 4.2 engine came out alongside the E type
Joe

[Joes66]

Chris
I am simply putting up information i have spent time researching in answer to a post
I am not really interested in any personal animosity or if your tired in some way of someone else's opinion
And I am certainly not deliberately trolling you
Its a forum after all.....
I only print things I have looked into, in some detail and from multiple sources
I am not saying I am 100 percent correct because I don't have jaguar original documents and I don't just use xk data either
Its just the sum of what I heave learnt
Joe

[christopher storey]

I don't know where you have been "researching" your knowledge but I am afraid that your postings have been largely incorrect ( the one correct statement being that the change from Moss to Jaguar all-synchro came at the time of the introduction of the 4.2 litre cars in late 1964 ) . The records which are posted on xkedata are ( apart from one or two typographical errors ) unimpeachable and come predominantly from heritage sources .
If you insist that I am wrong in my detailed information which I have set out , ( and therefore am misleading people ) perhaps you will let us know precisely where your research was conducted , and if that shows that I am wrong I shall be happy to correct the record, as it were

[Joes66]

Chris
Where did I say you were wrong?
Actually I would generally agree with the logic of mark 10 gearboxes having different gear ratios to an e type box
And also logical that a different model would have different serial numbers on the box
Especially if it had different gear ratios
But as above there are those reports that go against this
I found a few examples of similar claims that early 4.2 mark 10 gearboxes were marked as such
I have also already said more than once that I may be wrong
Do you even read my posts before you start to complain about them?
Because just like your research there is no actual definable proof either way
People can make thier own minds up
Maybe you should concentrate on those posters that like Steve's post above shows are clearly wrong according to you
And ask them why they have posted misinformation?
Considering they only built maybe 5000 or so mark 10 4 2s its going to be hard to prove one way or the other because hardly any are left
Maybe let's call up Jaguar and ask them directly maybe?
Happy at the end of the day for you to prove me wrong, but it won't change the posts that say otherwise will it?
This is my last post on this topic but I will look further into it and mail you personally if I find anything
Joe



Joe

[christopher storey]

Joe : if you go and look at xkedata and look under the classic saloons tab and then select Mark 10 and the various models ie 3.8, 4.2 and 420G you can then examine every single car that is on the xkedata register. All the manual gearbox cars that they have listed - and there are quite a few, to wit 17 3.8 , 7 4.2 and 13 420G for which manual numbers are given - have the prefixes and/or suffixes that I have listed. I read your posts with care . It seems we shall have to agree to differ, but frankly I am not going to waste my time arguing with you further

[dxke38]

Chris, interesting point you mention about some late 3.8 Mk 10s having a GZN gearbox that were full synchro. I have one of these that I removed from a 3.8 some years ago and assumed it was a Moss box with Overdrive. Now I know more about it I'll have to find a use for it.

[christopher storey]

Derek - and everyone else - I think there is an error in my post earlier where I said that 3.8 had JX - these in fact were Borg Warner autos, and I think GZN were Moss 3 synchro fitted to all manual 3.8 mark 10s - your box will in fact confirm this if the gear pattern is with reverse alongside first ( Moss) rather than to the right and back alongside 4th ( Jaguar 4 synchro )

[dxke38]

Chris you got my hopes up. I shall now have to re exile the box to my list of spares until the Moss becomes popular again'
Best regards
Derek

[Drdum]

Thank you for all your answers- and apologies for creating a hot debate here. Here are the rest of the numbers printed on the housing: DA20594 and C20019
Thanks!

[christopher storey]

C20019 is the Jaguar part number for the gearbox case on a Series 1 4.2 litre E type, so we come full circle : it is almost certainly an EJ gearbox on which the stamp has been very slightly misplaced so the the bottom horizontal line of the E has been lost