I've got this hydraulic Rotator that I want to disassemble and I'm having problems taking it apart. Any advice? Should the end caps come off?
A hydraulic shop will have the heavy tooling to unscrew the end caps. The two opposed holes at each end are the drive points, takes a lot of torque you do not have with that pipe wrench.
Looks like the same thing they use on boom lifts to rotate the platform. If its the same deal they aren't that bad. Just make damn sure you mark the position of both the end caps in relation to the body. If you have a seal kit it should come with the tooling needed to take it apart (and new lock dowels). After marking the end caps, loosen the 2 plugs on the side and pull them out. If you don't, it makes it really hard to unthread the end cap (oil will shoot everywhere so put a rag or something over the holes to prevent a huge mess). On the end shown in your first picture there should be 4 countersunk Allen screws. Pull them out. The outer 2 are where you thread the tooling into so you can use a prybar to unthread the cap. The inner 2 retain the dowels. Sometimes they fall out, other times you'll need to either drill them out and use an extractor or just drill them out completely. Once the dowels are out, unthread the cap. DO NOT REMOVE ANY INTERNAL PARTS UNTIL YOU VERIFY THE TIMING MARKS ON THE INTERNAL GEARS! I cannot stress that enough. The cap on the opposite end should be integral to the centre shaft so if you turn it with the other cap off you can inadvertently un-mesh the gears. I'd even go so far as to draw a picture or take photos with a camera. On the boom lifts it seems they just mark teeth at random as I've yet to see 2 marked the same. You'll see what I mean when you get it opened up. Just make sure you get both sets of timing marks lined up during re-assembly. Its a PITA to go back and move it a tooth if you mistime it. Once you've got it apart and new seals in, put it back together. Double and triple check your timing before you screw the bottom cap back on. Line up the timing marks you made on the body. The bottom cap isn't so critical. Tighten it up until its tight. If you need to back it off a bit so the dowel notches line up that's ok. If you're half a turn too loose there will be a fair amount of rotational slop in the actuator. Anti-seize the dowels and the countersunk screws when you put them in. As to why timing is so critical, if you're out a tooth, you lose travel in one direction and gain more in the other. Its kind of like moving the pitman arm on a steering box 1 spline over.
Believe it or not 95% of those actuators I've re-sealed on boom lifts those end caps came out with a 2 foot prybar. The odd one needed a 4 footer.