Syncro Rear Axel?
...BTW your Bieber avatar is awesome.-Malone
Are you planning on using an inline transmission as well and what electric motor will you use. I think with the extra weight off all this stuff plus the batteries the deisel itself will probably loose the mileage the hybrid part creates even if you can get it perfected and you will have so many arms flying around in the cab shifting between modes you'll look like an octopuss driving but it will be interesting to see what you can come up with. Experimenting is fun and we all learn from it here
I've done a lot of research on building electric cars. Pay attention to the batteries - I've seen somewhere big LiION batteries developed for small cars which last long and charge fast and the weight you save with that is really important. I've looked for them again but haven't been able to find them...they'd probably be great though. What's most important is that they deep-cycle very well; deep cycle optima car batteries don't deep cycle as well as solar/ wind batteries made for houses - they're more durable and made to last longer and deep-cycle better than any car batteries - you might want to look at them or else you'll be replacing your batteries very soon. As for the axles I don't know, good luck with all this-James