What is the difference between the J type and the D type overdrives. And how can you tell them apart?

Thanks, Carl

Speaking of m41s, I have two , a D, and a J that i dont need if anyones interested, I'm in Jersey.


Ozzi

'67 220s

The d-type also has a somewhat higher gearing in od than the j-type. D-type parts are getting hard to come by.

Lots of bits about in the UK I even bought a brand new D type main body a while back. The mainshafts are a real PITA though.

Regards


Pete

The Dtype overdrive has it operating solenoid on the right side of the ovdrive, held on by 2 screws.

The type has it in the left and the operating valve is integral to it. It screws into the buby of the overdrive and has a hex machined onto it.

The info that the J type is stronger than the D is a bit of an urban myth.

Regards


Pete

I recall you saying once before you'd managed to explode a couple J-types but never a D-type. Is that the case or do I have it backwards?
--
Justin 66 122E, 71 145S
Read vclassics!

That's right. The J type is physically bigger and the planetary gear and annulus are bigger. The unidirectional clutch was lifted straight from the D type.

However, whilst the cone clutch is physically bigger on the J type, the actual cone itself is aluminium. On a D type its steel. I've seen the cone clutch ripped to pieces on a J type. On a D alll that tends to happen is that the whole thing becomes so hot it stops working, but it will still transmit drive in non overdrive mode.

Of course some seriously uprated bits have been made for theb J and if you must have a really strong overdrive then a J is a good starting point. In standard form the idea that a J is better is frankly Bull Shit.


Regards


Pete

There is a plate on the side that should say "Norman de Laycock J type" if its a J type , you might need a good can of degreaser to find it as they get real dirty in normal driving.

I think the J types were painted black , the D types painted red. Although that just be what mine are. J types are the "newer" trannies, more durable than the D,


ozzi
'67 220s