Which auto trans would work well in a mk1 with a 1.9 tdi
Are you planning mTDI or eTDI? If planning on mTDI I would use the 010 from a rabbit/golf. Rare, but they do exist. They are also fairly robust units. Only 3-speeds and no lockup, though. They are completely mechanical units and would obviously be bolt-in. If going eTDI, you could still use an 010 or you could use one of the auto boxes from a mk4/mk5 jetta/golf. The o1m has 4 speeds and a lockup torque converter but is considered weak and failure prone. I happen to own a couple stock TDI's with the o1m and have not had any issues. Each of them that I bought, I got with failed transmissions although they both lasted over 200,000 miles which is pretty darn good, IMO. I have had one of them as a daily driver for 5 years now and it has been flawless. My wife and I are both very gentle drivers, though. I don't have any real first hand experience with the 09a tiptronic. The 09a is 5-speeds and lockup.
If you are planning on AHU/1Z then the 010 starter will not bolt up the transmission due to clearance issues with the block. I doubt it would clear the turbo either. I have no idea if it would fit the ALH and newer engines. You might be able to make it work with a gasser starter but I'm doubtful. I'd go 09A if you are using eTDI
Burn, where is the interference with the 010 and AHU/1Z?
Good thing you asked. You've jogged my memory that I tried with an AAZ. The AHU/1Z may be different. I know that the starter hit the oil return bung on the block (not just the banjo bolt but the actual block) so I ground that off and then it hit on the webbing on the back of the block.
Interesting. I was not aware but have not tried the swap.