Thanks to everyone for the help so far in the conversion to o-drive.
With the shaft getting shortened I am now looking at the M41. I had a great idea of replacing all the seals before I install it so it could stay in the car for many years. However, after looking at the diagrams I am nervous about replacing the middle seals in the o-drive unit for fear of having to dismantle the entire unit to replace two seals.
Any suggestions, has anyone else done the seals only? The unit tested good in a mule car, just some leaking. My thoughts are that if I have to take the entire thing apart it should be rebuilt, but I do not have the time at the moment.
Thanks,
Erik

You might want to double-check before spending the time jumping into your trans/OD: the topcover seal and speedo output o-ring seal are usually the primary sources of leakage.

When I switched to M41 (I rebuilt the transmission before hand), it seemed a litle daunting to be seaparating the OD/trans, but it really wasn't that big a deal. The trans and long mainshaft with eccentric separated easily. I would recommend replacing the gaskets on either side of the intermediate collar, as well as the seal at the output from the OD (pulling flange), the front trans gasket and the trans cover. Just be careful when loosening the 8 nuts on studs that hold intermediate collar to OD. I once snapped one of those studs and it was a bit of a job to R&R. On an earlie D type in the 444, one of these studs had been broken, and was the source of a slow leak. Also, speedo output "O"ring.

Cracking the OD off the Transmission can sometimes be easy, sometimes quite difficult. Sometimes it seems like the trans shaft is just locked into the OD guts with a great deal of tension, and they must be pried apart with a great deal of force. Sometimes they just slide apart.

But still, easier to replace that oil pump o-ring now than later when it has to come back out of the car first.

Be careful reassembling - I once broke the oil pump's aluminum collar (goes around the trans shaft on an eccentric) when I slid the two back together. And found that spare parts like that are not findable. Especially back in the pre-internet days. Sigh...

I haven't had to replace the seals on my M41, but I did do all the seals on my old M40, and dismantled the whole unit to do it. It actually isn't that hard to get them apart and back together again, but it is pretty time consuming. I think it took me about 3 or 4 evenings to get everything back together. Good luck!
--Ethan

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'64 PVMoneypit, '93 945 Turbo