TR2/3/3A J Type Overdrive in TR3A

[RonC]

I have a fully rebuilt J type OD from a 1973 TR6. I was planning an install through the cockpit into my 1958 TR3A which has a TR4 block. The plan was to keep the TR3 spring clutch since it has next to no miles on it. I now found that the input shaft front cover on the TR6 transmission has a sleeve for the release bearing/sleeve that is 1 31/32 inches in length. This would accommodate the diaphragm clutch. The TR3 transmission with 3 finger spring clutch has a front cover with a sleeve length of 2 3/8 inches. I am now stuck with do I go further down the rabbit hole with a clutch change?

My understanding is that the diaphragm clutch will require modification to the flywheel for mounting and isn't just a simple bolt on with same holes as the TR3 clutch? Can the front covers, with different sleeve length, be just unbolted and changed and then I proceed with sliding the transmission back on my block with TR3 clutch?

Will someone with a TR4 A type OD transmission want to consider an exchange for a professionally rebuilt TR 6 OD unit?

Ron

 

[CJD]

Or...just put the longer TR3 front cover on the box so you can use the TR3 clutch.

 

[RonC]

So far it looks doable and I can rob the TR3 cover from my removed transmission. Macy's Garage had a short Aug.14/18 blog about the varying sleeve lengths and hangup of clutch fork/bearing in travel if mixing up parts. They never did note if they stuck with the older 3 finger clutch with appropriate cover, fork/bearing or switched totally to TR6?

 

[CJD]

That's the easy fix. I think the short snout will even work in place of the long snout...but I can't confirm that for sure. The long snout will NOT work in the newer, diaphragm clutch, as it will hit the diaphragm.

 

[RonC]

I was hoping that there would be other TR3/TR4 early frame owners that could give feedback on their rear J type overdrive gearbox mount. It is amazing how creative gear heads can be in fabricating or finding a custom mount that works! Someone out there?