1998 Pathfinder VG33 to TD27 Conversion

[peachepe]

Hi Everyone!

 

I'm in the process of a VG33 to TD27 conversion. The VG33 is no longer viable and diesel just makes sense where I live. The TD27 is the mechanic pump version, no turbo.

 

I have a manual transmission ready, but I'd like to keep the Automatic transmission. I've been reading as much as I can find here's what I understand so far:

 

- The auto trans has it's own control module

- The trans control module still uses input from the ECU for Throttle position sensor and "engine speed" sensor.

 

The TD27 doesn't have any of those sensors so I'm wondering if the Auto Trans is going to work at all, or work horribly.

 

Any help is really appreciated. I've tried searching a lot before posting but couldn't find anything specific to my problem.

 

Thanks! 

[Slartibartfast]

The stock trans computer won't work well (if it works at all) without the throttle position and engine speed signals. Even if you came up with a way to feed it the info it needs, I'd expect its shift points to be all kinds of wrong for a TD27. Maybe you could find a donor D21/WD21 that came with a TD27 and an automatic and use its computer, harness, and sensors. If you don't mind shifting your own gears, but like the auto for its torque converter, you could ditch the computers entirely and run a rail shifter like this one.

This also assumes you have the bellhousing you need to connect the TD27 to your existing automatic. I'm not 100% sure but I don't think they use the same bolt pattern, and I wouldn't be surprised if the diesel versions used a different torque converter too.

The closest I've seen to this build was Ekim Naelcm's truck, which is a WD21 that he TD27-swapped and kept automatic. IIRC he got a trans from a VQ R50 to work with his TD27 by swapping the bellhousing, but had to have a torque converter custom made. He had a full donor, and wasn't crossing platforms like you are, but he'd be the guy to ask if you get stuck trying to figure out what parts you need to make this thing work. He posted a bunch of info about his swap on the NPORA Facebook page a while back.