8000 series Gravelys

I have several 8000 series Gravely tractors and parts from our mowing business years ago. We ran four of them on one crew. We had three 50 inch decks and I think it is an 8199 with a sixty inch that pulled a 40 inch gravely wing. still have those and others stored in a loft. Now to my question; I would like to take two of the transmissions and turn them pto to pto to make an articulated four wheel drive. I want put a Kubota three cylinder diesel on the front transmission with it facing forward. I would us the reverse cluth to gain forward travel. If I put a driveshaft between the ptos and engage them will it drive the rear trans axle the same as the front or will it turn the other way?

The rear one will spin the wrong way when you hook pto to pto.

I've never had a Gravely transmission apart, but I assume that powering the rear transmission as you describe would change the direction of rotation of the rear drive wheels.

Your project sounds possible in theory, but a real challenge to make it work. One thing to consider is that the PTO clutches are inside the transmissions, and are the "weak link" of the tractors. The forward and reverse drive clutches are external, are relatively easy to service, and have a thick lining material. The internal PTO clutch has a cone shaped facing that is very expensive and difficult to access. I'm not sure how well it would hold up for your intended use. The second issue I see is that the 8000 series has eight forward speeds (four speed with hi/low), but only four reverse speeds. The reverse speeds are equivalent to the gears three and four low range and gears one and two high range.

You might want to look at the Gravely operator's manual to see the rather low speed range of your proposed vehicle. Keep in mind that the speeds listed in the manual assume a 3600 RPM engine speed. You also might want to consider what would be necessary to change gears and operate the drive and PTO clutches in the two parts of your tractor.

https://manuals.gtcoa.com/pdf/8000_Series_Op_Man_19820800.pdf

Some more thoughts.

The transmissions used for the four wheel Gravely tractors began as modified versions of the transmissions used for the two wheel Gravely Tractors. Some time ago I bumped into a series of youtube videos where a fellow used two transmissions from two wheel Gravely tractors to create a four wheel drive machine. I've only glanced at one of the videos, but you might find it interesting.

https://www.youtube.com/watch?v=csKUeNa-2pA