I would love to see some detail pics of this in the Forums. It sounds very interesting :-)

Er, yeah, goes something like - servo operates double acting master ram on the radio deck, fluid travels to/from the double acting slave ram on the axle. Each ram has 2 seperate fluid chambers, so they do work in pull & push. Then there's 2 seperate loops for front & rear. The point of the exercise was to get rid of unsightly equipment (Servos) mounted on the detailed axles, whilst at the same time doing something that hasn't (As far as I know) been done before. The diff lock rams are single acting - servo acts on master ram, fluid travels to slave ram & shoves the piston out. A spring returns the piston when the servo releases

It was an interesting project, but I don't think I'd try it again, lots of work involved. What would you like to know? It operates at 1:1 ratio ie the rams are the same size & travel & it's closed loop (No reservoir or pump etc, to keep things simpler). Motive fluid is water, with a few drops of shock oil for lubrication. Rams are double acting (Work in both directions) made of 13mm aluminium. Pistons are also aluminium with double o-ring seals - I wanted proper ram seals, but they're not available at this size. Screw-in end caps & loose shaft seal retainers are phosphor bronze, shafts are silver steel. Er, tube fittings are by SMC, for 3mm nylon tubing, rose joints are Traxxas. Next job is to come up with a bypass valve block for ease of filling/bleedin g/adjusting steering position etc. Steering is operated by 2x high torque servos with their own power supply. Diff lock rams are single acting, spring return, 6mm aluminium bodies, PTFE pistons & end caps

Cool!! I would love to learn more about the hydraulics.