Hi to alls
I would like to understand the difference when mounting a Moss gearbox + right overdrive (before 1964) and Full synchro mesh + right overdrive (after 1964)

My understanding is that the total depth of both components (gearbox and overdrive) is the same as long as the propeller shaft is the same, even if the latest overdrive seems less deep that the previous one. In that case it would mean that the rear casing of the latest overdrive has to be a little bit longer. Are those assumptions right ?

My understanding as well is that channel bracket to fix the rear engine/gearbox/overdrive on the chassis is the same on both versions, with same spring retainer shaft fitting in the rubber bobin housed in the channel bracket.

You will find attached my understanding


Could you confirm that point . pictures, diagrams and photos are welcome.
Thanks in advance

 

So long as the all synch + overdrive has a long tail Mk2 overdrive, it will all fit. Other A type compact overdrives don't have the long tail. Without the long tail, the rear mount has to be swapped to one from an S type and the prop shaft has to be lengthened.

Glyn and I were a bit confused by all this and had a long discussion in a thread a few months ago before finally sorting it.

 

Thanks Peter for your quick feedback

Would you have picture/photos/diagram for overdrive with a long tail and the ones without long tail.
Thanks in advance
My best regards
Gérard

 

https://www.jaguarforums.com/forum/m...-218301/page2/

Post 25 in the link above has photos of a short tail S type and long tail Mk2.

 

Thanks to all comments.
I think I have understood the difference between short tail (like the one mounted on a S-Type) and long type (like the one mounted on Jaguar MK2 non synchro gearbox)

Now the question about the Jaguar MK2 upgrade starting from 1965 including Full Syncro mesh gearbox + right overdrive (short or long I don't know ?)
In that way, what is the mounting between the overdrive and propeller shat ?
Is there a new channel bracket (like the one on the S-Type) ?
Has the MK 2 propeller shaft been changed ? (Longer ?)

Thanks to answer : then I will fully undersatnd
My best regards
Gérard

 

If you use a long tail, the mount and prop shaft are the same as with a Moss + overdrive making the swap straightforward. With the short tail, I think that an S type rear mount will work (as I've never done it, I can't say for sure). Certainly people have converted Mk2s with short tail overdrives as there are a lot of them about from S types and XJ6.

 

Following your different answers, its clear that I have an overdrive with short tail (probably type A compact) mounted on the Jaguar MK2.
The problem is that the mechanic who has made the modification has not used the S-Type mounting (different channel bracket/spring/rubber bobbin) but what I would call a makeshift solution with a non-standard part.
The mechanic has leveraged on the MK2 original channel bracket but when looking inside the spring seems
And of course, the propeller shaft has been modified because it was too short : I cannot identify the change. The only thing I can say is that this new propeller shaft mounting is not the same as the original MK2.
You find some pictures below with a few questions/comments from my side.
What do you think about this makeshift ?
Am I at risk with this mounting ?
Thanks for your inputs
Regards
Gérard

 

I'm away from home and don't have access to my car or books for a few days, so it's a bit difficult for me to answer your questions. Possibly Bill Mac may be able to help.

There definitely should be a spring in the rear mount.

 

https://valvechatter.com/?cat=771

There are some pictures in the link above of the engine mount.

It's not clear to me what the mechanic has used on your car to extend back from the standard o/d pin back to the Mk2 mounting beam

Incidentally, the split pin and washer are only aids for installation. They are supposed to be removed once the mounting beam is bolted up.

 

Hi to alls
This message will undoubtedly override the previous ones, even if they remain valid for the record of my investigations.
It's relatively simple and logical: when Jaguar updated its MK 2 models after September 1965, they introduced the full synchromesh gearbox and a new overdrive, still referred to as the compact Type A.

This overdrive was designed for the Jaguar M2 and S-Type but featured different attachments (channel brackets) and of course different propeller shaft.
The overdrive installed on the current engine (the one completely rebuilt) is a Type A Compact overdrive but with a short tail.

I believe it is a model intended for the Jaguar S-Type or another, but not adapted for Jaguars MK 2 manufactured after 1965.

The mechanic in charge of remounting the block engine must have found out a solution. Unfortunately, he has not investigated.
He installed a part to ensure the connection between the short-tail overdrive and a new propeller shaft instead of conducting investigations and discussing it with you

I don’t trust this part or its installation (Do it yourself solution), and furthermore, I don’t know what was done to the propeller shaft.
I would like to restore the original setup with a Type A Compact overdrive (long tail), reinstall the rear assembly (channel bracket) identical to that of the MK2, and recover the original propeller shaft

Can somebody help me in that way (in finding parts especially)

Thank you in advance.
My best regards
Gérard

 

A simpler alternative might be (I'm not absolutely certain that it will work) to obtain the support beam used on the S-type. Most likely it bolts to the body the same as the MK2 and will line up with the mounting on the overdrive. Probably someone at Martin Robey (or SNG) can give good advice.