Whether you are travelling in FORWARD direction or REVERSE direction, the INPUT PULLEY rotates in the same direction To "change the direction of rotation" of this pulley would require either reversing the rotation of the engine, or some kind of selective idler pulley assembly. In regard to loading from "dynamic braking": Yes, in theory, abrupt dynamic braking will "shock load" the entire transmission from input pulley to axle shafts output......but no more so than sudden, full applications of the hydrostat to move in either direction from a standstill. The deciding factor in all this would actually be in "how much traction" is available at the drive tires' contact patch. If little traction is available, and wheel slip is likely, the energy of any action will mostly be spent into the ground, without much worry of harm to the tranny. If, however, traction is high.......any action will result in the energy being divided proportionately between the ground and all components "upstream" in the power train. Frequent, abrupt changes of direction and sudden, full application starts will ultimately result in the same kind of wear to the oil and the "hard parts" that pulling too heavy a load would cause. I doubt that "changing your mowing pattern" (to somehow minimize using reverse) would provide a benefit in the long run. Gentle stops, starts, and braking would certainly provide some reduction of wear if compared to "thrashing the machine" on the other hand.

Thanks for the detail, Mownie. I guess I understand even less about the working of the hydro than I thought, even though I have had one since 1996 (my JD 165H). Is it correct that the pedals for the transmission do nothing but open a hydraulic valve? ie: pulley keeps running in same direction, so pump contiunes to run in same direction, but the fluid coming from pump is being routed differently for forward or reverse? By the way, I fully agree with you about smooth starts, stops and aceleration as improving life. My three sons spent all of their teen years driving the 165H, and I was forever on their backs about slowing down, being easier on transmission, turns, etc. Fortunately, even with that abuse, the machine lasted great, and first fluid change was after 20 years and probably 1500 hours+. When I sold it 5 years after that, it was still running great. Of course, it had had a few pieces changed like deck spindles, but very few. I don't expect the LT160 to last like that, but I don't have three teens driving it either, so we may sort of balance out if I pay attention and get more knowledgeable from boards like this.

The simple answer is yes, the pedal (or hand lever if hand controlled) moves a valve inside the hydro unit to direct the flow of oil from the hydraulic pump to the hydraulic motor(s). The PUMP always turns in the same direction and oil flow through the pump is always in the same direction. The VOLUME of oil flowing through the PUMP is always the same (for a given RPM). When the direction control pedal (or lever) is in NUETRAL, all the oil output from the PUMP is directed through the valve and dumped straight back into the sump cavity of the tranny case. When the control pedal (or lever) is moved to FORWARD or REVERSE, the control valve moves and begins flowing SOME oil through the DRIVE MOTOR(s) in the correct direction to make the motor rotate for the corresponding direction of travel for the machine. Depending on how fast you want to go, you will move the pedal a little or a lot. If you move it a little, you will go slow (and most of the oil will be dumped right back into the sump with just a little oil flowing through the motor). If you move the pedal all the way to the end of its travel, you will go fast (with practically ALL of the oil flowing through the motor and very little being dumped directly into the sump. I should point out that after the oil passes through the motor, it is dumped back to the sump. There are provisions in some hydro units to direct oil through a filter (either external or internal) so that debris and metal flakes can be trapped, but essentially, what I described above is the way hydros operate (generically). The "dynamic braking" of a hydrostat is due to the hydraulic principal that a liquid can not be "compressed" (it can be "pressurized" but not compressed to to a smaller volume), and in that respect, when you flow oil through a hydraulic motor at a given "flow rate", the motor will only turn as fast as that volume of oil flow will allow it to turn, regardless of load. When you "let up" on the pedal (or lever), you decrease the amount of oil flowing through the motor and thus the motor speed MUST also decrease and the vehicle speed is retarded.

If your pulley splines do wear out, it isn't very hard to change to a new pulley. I've heard on many occasions that a call to Tuff Torq service department will get you a new pulley kit for free.

Thanks again, Mownie. Couldn't be more understandable, and really quite simple and logical once it is explained that way.