Looking for anyone who has technical knowledge on how the front and rear d9 would operate together. Transmission and steering control etc.

Ultimately looking to possibly build a modern version with two D9T's

 

Welcome aboard,
Wow! That'll be a BIG project. You will need a very FAT wallet! There is a spec sheet in the ACMOC library but you need to be a paying member to access it. If you are really serious I found a DD9G parts book on eBay: 
www.ebay.com/itm/372893369407
 Craig

Hi, banelson.
What are you gonna do in your 'spare' time?????

The controls for the rear tractor were air operated from the front unit. The front seat was angled about 30 degrees to the right to make it easier to turn around to see what the back tractor was doing and all the transmission and steering controls were under the left hand. The steering controls were 'crossed' so turning the front tractor right turned the rear tractor left and vice versa. There were two 'loud pedals' on the floor under the right foot, one for each tractor.

Each paired unit was set up so that the two tractors could be easily separated and driven separately for transport.

See attached images:



I do have more. Send me an e-mail - in my profile - and I'll send you the rest.

Just my 0.02.

Hi, banelson.
Further to my post above. it was not just recommended but pretty much imperative that the rear tractor be at least throttled back quite a bit when making sharp turns or it would push the rear of the front unit sideways or pull it depending on whether travelling forward or reversing at the time.

There may be some issues with 'timing' when setting up two D9Ts to work in tandem 'coz the Ts are differential steering and getting the same amount of differential speed on both tractors but in opposite directions might be a challenge. Also, the rate of turn becomes slower the faster the tractor is travelling.

There is a 'nuther' little 'trick' that these tractors have up their sleeve too which could cause problems if the operator is not VERY careful. Moving the steering tiller control beyond a certain point starts the track on the side you are turning toward going in the reverse direction to the opposite track, enabling spin turns - - - which could conceivably cause some 'havoc'. Maybe that function could be locked out to eliminate problems before they arise.

Also, it might be a good 'trick' to have a full dash readout for the rear tractor readily visible on the front unit 'coz these tractors are pretty much completely computerized. If the back one develops a computer fault and you don't know about it up front, ti could cause a disaster. On the 'plus' side, this MIGHT make setting up the engine, transmission and steering controls a little easier if you can arrange having the signals being sent electronically instead of by air controls and synchronize the computer systems.

But you don't hafta take any notice of me. I'm not a mechanic, 'justa pore, dumm bulldozer op'rator'.

That said, it would be a HELLUVA sight to see

Justa cuppla my 0.02s.