Swapping a gearbox

[Surveyme]

Hi all
I want to change my Series 2a gearbox for a synchronised one (same series but slightly later model I understand)
Can anyone recommend where I can purchase from with the supplier taking mine in part exchange?
All working but my wife finds it hard to drive.  Ideally would like to put in an auto box for her (medical grounds) but not sure if that's possible?
Thanks
Neil

[AlexB]

I would suggest that there isn't much chance of this
Most (and there are fewer and fewer folk that rebuild gearboxes nowadays) folk rebuild your box, they don't have a stock and the later all synchro series 2 box is like rocking horse doo

[nathanglasgow]

I have a later S2a all synchromesh gearbox, the rocking horse poo variety, sitting under the workbench I could be persuaded to sell . I'd imagine it would need new seals at the bare minimum as it's sat there for 8years since I removed it from a vehicle I broke for spares. We are 500 miles apart so a bit of a transport problem.

[Peter Holden]

They are actually quite a nice gearbox, we have one in our51 80" attached to a very nice 2.25 S2 petrol engine.

I am going to go the other way putting a 6 cylinder S2 bellhousing on my S3 gearbox when I get round to it so that I can refit the original type of engine

Peter

[simonbav]

This post was on the S2C Facebook page yesterday:

[diffwhine]

I think you will find an auto box up against a 2.25 (petrol?) engine will not behave well. There simply is not enough power there to run one effectively. You are also heading into the realms of modified vehicles and losing your status as an historic vehicle.

There are ways of doing this to at the very least get all synchromesh. The simplest is to fit a Series 3 box although it would be foolhardy to fit one that has not been overhauled, as they have some weak points (specifically in the problem area you want to resolve - 1st/2nd synchromesh). You would need to do a small mod to the bellhousing crossmember to allow the slave cylinder clearance and re-route the slave pipework. Other than that, its pretty much plug and play. A gearbox supplier may take your existing box, but only for its exchange value which is something like £200. You are more likely to find a private sale Series 3 box for around £250 - £300 out there and then have it overhauled. As it happens, I've got two. One is for sale, but condition unknown and the other one I'm keeping.

This leads on to the second option. Rebuild a Series 3 box with a 2A bell housing, primary pinion and layshaft front gear. I have never done it, but know of several people who have done this. The reason why I'm keeping the second S3 box is because I plan to do this to my 2A so its easier for people to drive who are unfamiliar with "crash" boxes.

If you do consider the S3 box option in some form, you have to ask how much advantage there is likely to be for your wife on medical grounds? The shift movements are broadly similar to a 2A, and the clutch action is also similar. Aside from having to press the clutch less on a Series 3 as you don't need to double declutch on downshift, is there any other real advantage in all this time and outlay?

[GlenAnderson]

The series three gearbox does have a noticeably lighter clutch action, which might factor in a decision. It is why I run one in my Land-Rover.

[Peter Holden]

That is because it uses a car type release mechanism and isn't as robust as the S2 version.  When fitting a S3 gearbox alway fit new components to the release mechanism

Peter

[Wittsend]

I've fitted a remote servo on the clutch line. I have a Series 3 box fitted. The servo action makes pressing the clutch even lighter.

Also

I never use 1st gear. Always start off on 2nd gear - except if on a hill or towing a load, 1st gear not needed.


 

[nathanglasgow]

Hi Neal, any thoughts on the offer of full the full syncro box?

[Surveyme]

Thanks to you all!  Much to consider - So much for my wife's medical issues!!! 😂

I don't think swapping is going to be something I'm going to do myself anytime soon.

I think this might be something I take offline for now

[Graeme]

An interesting discussion, thanks guys.

I'm also looking at a SIII gearbox swap, mainly to get a vehicle that's a bit more approachable to drivers that can't get their feet around double clutching.

I've got a D suffix SIII box that's in bits and will overhaul.  I'm liking the idea of using a SII bell housing so I can keep the SII clutch and still have the option of putting the SIIA box back in. 

Is there anyone around who has done this conversion, and what suffix SII parts are compatible with the later SIII boxes? 

[Oddjob]

I fitted a TD5 clutch pedal with the over centre spring which really helped lighten the clutch.
I think theres now a different master cylinder you can fit which does the same thing. Can't remember the make, it's the UK people who make decent brake drums and clutches for LR's.

found it... https://lofclutches.com/shop/clutches/series/lof-power-master-for-defender-series/

[GlenAnderson]

An interesting discussion, thanks guys.

I'm also looking at a SIII gearbox swap, mainly to get a vehicle that's a bit more approachable to drivers that can't get their feet around double clutching.

I've got a D suffix SIII box that's in bits and will overhaul.  I'm liking the idea of using a SII bell housing so I can keep the SII clutch and still have the option of putting the SIIA box back in. 

Is there anyone around who has done this conversion, and what suffix SII parts are compatible with the later SIII boxes? 

You can't use a Suffix D series 3 gearbox with a Series 2A bellhousing as the later "Coffin Tooth" gear shape won't mesh with the earlier input shaft. You can either build the gearbox up with suffix C parts, or look for an earlier A-C series 3 gearbox instead. Personally, I would stick with the complete Suffix D one, and go with the later clutch release - it's the strongest variant of the LT76, has the lightest clutch action, and when the eventual and inevitable time comes that it needs rebuilding, it's a stock item not a hybrid that the rebuilder has to work out what on earth is going on inside it.

[Graeme]

You can't use a Suffix D series 3 gearbox with a Series 2A bellhousing as the later "Coffin Tooth" gear shape won't mesh with the earlier input shaft. You can either build the gearbox up with suffix C parts, or look for an earlier A-C series 3 gearbox instead. Personally, I would stick with the complete Suffix D one, and go with the later clutch release - it's the strongest variant of the LT76, has the lightest clutch action, and when the eventual and inevitable time comes that it needs rebuilding, it's a stock item not a hybrid that the rebuilder has to work out what on earth is going on inside it.

Thanks for that, very useful information.  I was wondering about the new part numbers with the Suffix D.  Will proceed with a straight rebuild on the gearbox and deal with the changes to clutch hydraulics and chassis.