The Stovebolt Site Forums The Parking Lot Big Bolts PTOs

PTO's are specific to the transmission. They can be assemble in many configurations and there are as many models as there are trannys. Basically there are single gear units where the driven gear in the PTO is the one on the output shaft. These are made for LH or RH PTO openings. Then there are spur gears(straight) and beveled gears(angled)and these can be cut in two different directions to match the drive gear in the tranny. Then throw in the fact that the tranny drive gear may be at the front of the opening or the rear of the opening. Starting to get the picture....? Now just for fun let's throw in the HP requirements of the device you wish to operate. Small hydraulic pump (?) or large air compressor..? OH..and let's not forget the RPM requirements because it may mean the engine must run at high speed (2000) or it may have too much speed and no power at idle but the the PTO is going like a house afire..

Comes now the double gear PTO's for which we need all the above info and a willingness to spend more money..a LOT more money often. The PTO must have a lower HP capacity than the drive gear inside the transmission and be the weak link or a very high dollar transmission can be split wide open. I've seen RoadRangers break the entire side of the case out due to a mistaken PTO job. There are SAE 6 bolt openings which is common and there are also SAE 8 bolt openings on some heavy duty transmissions. There are shaft high(12 o'clock) and shaft low(6o'clock)assembles, forward and reverse models and two speed PTO's which are really transmissions unto them selves. Enter now the engine drive units that mount to a crankshaft, yep you read it right.

Boy..I'm getting dizzy. Well that is enough PTO info for you novices to digest in one sitting but the bottom line is don't assume anything and get to know your local PTO specialist before bolting something on just because you think it fits. Next week we will discuss specialty PTO's for automatic transmissions that must be pressure fed and some other surprises. Don't miss it.