I have a 73 ford 4500 TLB. This afternoon she started being slow to go into forword, and then stopped shifting into reverse. I check the trans fluid and it was low - it took about 3 gallons of fluid. it will move forward with no problem but will not shift into reverse. I have notice a hydraulic leak in one of the power steering hoses in front of the engine - not sure if this is related or not. Anyone have any ideas?
I would start at the shifting lever and check all the linkage down to the trans housing, make sure the lever at the trans puts the machine all the way into the reverse detent as well. Some times worn linkages have to much slack or get bent just enough after repeated tries to make them go, even a roll pin that has failed on a shaft holding a different linkage in time can cause a issue. Once that is checked you will need to check some pressures to the clutches. If the machine will load a bucket in 1st gear forward spinning the tires then the issue may be linkage, shaft seals, rev clutch piston seals, clutch plates and disc's. If it does not have power when trying the forward push, then you are back to charge pump, converter, shaft seals, f/r clutch pack pistons, clutch plates and disc's just my thoughts after owning a few over the years.