THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

I am not as technically savvy as knowing that but there are a couple of things that I can say. The bell housing has a bolt pattern that has to match the back of the engine block or you will need a converter plate. Where the bell housing connects to the gearbox there are normally four bolts in a square pattern, so could be interchangeable or new matching holes could be drilled.
The torque converter bolts to the plate which we can call the starter ring which bolts to the engine crank. Running into the torque converter from the gearbox is the layshaft which also acts as an hydraulic pipe with a seal.
To interchange a gearbox from one vehicle to another the parts inbetween need to match up. The bolts patterns, the length and diameter of the layshaft. The size of the torque converter. The size of the bell housing. The size of the starter ring so the starter motor engages.
Jaguar used obviously the same engine the XK from 1948 through to 1996. I think the bolt patterns would be the same so I would have thought any gearbox designed to fit an XK engine would go into the S Type with possibly some interference changes to the gearbox tunnel, possibly with a different length propshaft and change in the gear change mechanism as some will be designed for column change and others for gearbox tunnel top.
Anything is possible it is just the degree of difficulty involved that makes it hard.

Thanks Rob. That is great information. When I next get the old girl up in the air I can check out those things. Could I have some kind of hybrid? it looks a bit like the torque converter is the same as standard on the 65 S-type (based on SNG Barrett parts pictures) but the actual transmission is a later model. is that even possible?

No problem Rob. You know vastly more than I do about the Automatics.

Sorry Glyn my mistake which I have corrected. No such thing as a BW30.

Rob. Is a BW30 & a Model 8 the same thing or were both fitted to the 420?

We discussed in http://www.jagstyperegister.com/forum_new/viewtopic.php?f=17&t=1184 the different types of gearbox which might have been in the S Type. I questioned it as mine is a BW35 on the plate but did not have the gear set that it should have. I have now ascertained it is a BW35 but from a Daimler 250V8 and as you have stated the dipstick is on the right side of the engine.
In researching my dilemma a couple of things were learnt and you are going to have to get under the car to check these out.
First what is your gearbox case made from? Alloy or cast iron? Alloy could be BW35 and beyond. BW65 or 66 from an XJ6? Cast Iron and it might be the BW model 8 from the 420.

Secondly is there an adapter plate between the bell housing and the back of the engine? This might determine if it is a Jaguar gearbox or another manufactures box with an adapter plate.

Third. Check where the dipstick filler pipe attaches to the gearbox. The top might be on the left side in the engine bay but attach to the right side on the gearbox with the filler pipe coming up over the top of the gearbox from the right to the left.

Lastly can you see the ID plate and get a photo of it. Mine is tucked up on the left side of the gearbox unfortunately above the exhaust pipes. I had to get my phone with the camera on tucked up between the pipes and the tunnel wall to take several photos before I got a clear one of the plate. The plate should tell you the make and model number of the gearbox and the serial number.
Attached are a couple of side on shots of a BW65 and a BW66 gearbox from the later XJ series but they clearly show where the I/D plates can be found. Then there is a photo of my plate showing the information you might find.

[attachment=0]BW65.jpg[/attachment][attachment=3]BW66.jpg[/attachment][attachment=1]IMG_9538.JPG[/attachment][attachment=2]IMG_9524.JPG[/attachment]

Well, the saga of trying to identify my auto transmission continues. The car is finally running - albeit not that well, but that's a minor issue - and I have been able to drive it around the block twice. :D The transmission shift is definitely P,R,N,D and not P,N,D,R as it should be for a DG250 transmission. And DG250 is definitely what it should be as a '65. If the transmission had been replaced by a BW35 from a later year the transmission dipstick would be on the right hand side, but it is not - it is right there alongside the oil dipstick on the exhaust side of the engine. I am bewildered. Can anybody offer any idea as to what is going on here?

The switch is under the dash; attached to the steering column on the left side. I have detached it to check the wiring and to reattach it when I get the shift gate thing sorted. I found some instructions in the service manual that look promising. But still no idea about why the starter still works in all positions. I am thinking that the switch has been bypassed somehow by a previous owner. It sort of looks like the anti-creep and thermo-electric choke have been bypassed. Lots more mystery than I anticipated. Still it is keeping me of the streets and out of the pubs - oh! - I can't go to the pub - it's closed until further notice.

[quote]I have now put in a new (NOS) neutral safety switch, correctly wired[/quote]

Where is your safety switch located as early S Types with the DG250 had them under the dash and the later cars with the BW35 had them on the side of the gearbox?

In most of the pics I have seen of 65s the transmission gear indicator goes P N D L R. That is - Park and Reverse are at opposite ends. That is the way it looks in the parts diagram also. So I am assuming that that is what I should have. At the moment I can't get the pawl to engage in the various slots properly.

I have now put in a new (NOS) neutral safety switch, correctly wired, as far as I can tell, and the starter still operates no matter what position the switch is in - very mysterious - and a little dangerous. If anybody out there could offer a clue as to what is going on here I'd certainly appreciate it.