Laycock Type A

[maze]

Hi,
Need some guidance on checking one of these out. I have one mounted on an xke 4-speed box and intend on setting it to a 72 V12. What should I do to make sure it's OK?
Thanks, Max

 

[Marvin Gruber]

Huh? You say you have a A type overdrive on an XKE 4 speed trans? I have to see a picture of that. Never heard of that done. Then putting it on a V12!

Marv

 

[maze]

Marv,
I picked up a unit already tied to the tranny and on measuring dimensions on my 72 e-coupe,it looks like a fit to the driveshaft. Only difference is that the bell housing needs swapping since it has one that fits the 4.2 liter. These can not be used on the shorter coupe or convertibles, pre-v12.
I don't want to open anything if I can avoid it, thus trying to find how good it is. I found something about powering the tranny with a small electric motor and that may be a good enough, but don't want to miss something; yanking the engine from the car is bad enough to do once!
Max

 

[Marvin Gruber]

Some of the older Jag sedans (50's and 60's) had overdrive trans. Never heard of one being put into an E type (6 or 12 cyl. I've had a number of XKEs, not an expert by no means but don't think it will work properly. Go to the Jag forum on this website and ask the same question.
BTW- yes you can check the overdrive unit using a 1/2 drive drill motor to power it up. You will also need a gauge to check pressure.

Marv

 

[Tinkerman]

I agree with Marv about the 1/2 inch drill. I used a heavy rubber hose for a connection. I slit the hose on the one end in four places slid it on to the tranny shaft clamped it down with a hose clamp also clamped it on the drill.
I have pictures but am having trouble getting them into the forum post. If you are interested I can post them to you. Send me a personal message with your email.

Cheers, Dick

 

[Don Elliott]

We checked the output pressure (325 psi) of an "A" type overdrive for a TR3A on my neighbour's lathe. It had enough power to drive it. Some electric drills will work but many are not powerful enough,

 

[HerronScott]

Not sure how accurate this is but found it in a Jaguar forum post from a little over a year ago.

Jaguar forum post on overdrive

"Any long wheelbase E-type (i.e. any 2+2 of any series, plus the V12 OTS) will fit an XJ6 overdrive box with zero modification to the car. Absolutely zero. Same mounts, same drive shaft etc.

Many in Europe do this because we have lots of XJ6 overdrive gearboxes whereas you don't in the USA. An MOD box is also bout 15% of the price of a 5 speed conversion, so that's another reason...

The only change you need to do if you have a manual car already is swap the tranmission tops between your existing box and the overdrive box. This brings the gear lever out in the exact same place as the E-type. "

Scott

 

[Don Elliott]

Others have built their own devices with an electric motor and a belt drive.

 

[TR3driver]

Some electric drills will work but many are not powerful enough,

IMO what you want is a 1/2" drill motor that turns at the lower speed (like 850 rpm). One of those 3/8 things with a (top) speed over 1000 rpm hasn't a hope. My old Milwaukee has no trouble turning the gearbox & OD, although you can hear the speed drop just a bit when the OD kicks in.