1966 3.4 S Type Gearbox

[LittleJonah]

Dears,

I have the above S Type which has been converted from an Automatic to a manual, by whom and when do not know. My question is how can I trace exactly what gearbox and year model mine is from, the number being KBN179. Or indeed what Jag did it come from. Also I attach the Heritage Certificate which I received recently according to the plate on the car. It is annotated with my feedback as clearly my car does not match fully with what is registered, hence why I believe a conversion. 

My next question is I want to replace the current gearbox with a fully recondition one. Any advise who to use/buy from ?

Many thanks for any input and advise.

Derek Jones

[ChrisDixon]

Hi Derek I also have a '66 S which has been converted to manual. The correct gearbox for this is the jaguar all synchro and the serial numbers started at JBN, so at a guess KBN is a continuation of that series. You don't say if yours has overdrive. What's wrong with the box? These boxes aren't cheap to rebuild, and I'm not sure on parts availability, so depending on whether you want originality or improved gearing you could consider a 5 speed conversion. The benefit of an auto conversion is the gearbox tunnel is bigger which means the box can be removed without disturbing the engine.

[LittleJonah]

Hi Derek I also have a '66 S which has been converted to manual. The correct gearbox for this is the jaguar all synchro and the serial numbers started at JBN, so at a guess KBN is a continuation of that series. You don't say if yours has overdrive. What's wrong with the box? These boxes aren't cheap to rebuild, and I'm not sure on parts availability, so depending on whether you want originality or improved gearing you could consider a 5 speed conversion. The benefit of an auto conversion is the gearbox tunnel is bigger which means the box can be removed without disturbing the engine.

Hi Chris, many thanks for your response much appreciated. Yes it does have overdrive. Why do I want to replace, simply said and by example if you want to change into 2nd you have a 50/50 chance of hitting reverse. Sloppy and floppy !

[ChrisDixon]

That sounds like the mechanism to stop you doing that isn't doing its job. There is a spring mechanism that should require a firm push of the lever to the left to get to the reverse plane. If the box doesn't have any other symptoms (noise, judder on overrun, bad syncros) I'd explore that avenue before going any further. I'm not sure if it is possible to get at the mechanism with the box in situ though, so you may need to remove the box anyway, Regards, Chris.