Combines torque sensing spring

Had similar problem with my 1688. Replaced the spring with a new, heavier one. Saw the two side by side - the old one was about 1.5 inches shorter. The problem with the rotor slowing has gone away. I gather some springs may have been of poorer quality steel - is your dealer using up old stockIJ Mechanic advised me to make sure to keep the unit greased so the moveable sheave can move.

My belt slip too on a 2188, changed the spring to a heavier one in 1998 and it is still going

Change to a new updated heavy spring and make sure rotor belt is properly adjusted.

Any torque sensor needs grease DAIlY.

Have a 1993 1688. Always slow rotor speed down all the way before winter storage. This takes tension off the spring, and aids in longer life. Never had a problem with rotor belt slippage and combine has 2800 hrs.

I have had 3 different heavier springs , all have ended in the same result after about 150 hours of use. All addjustments ,meaurements , checks . wear etc have been checked and rechecked. Seperator belt tension is at maximum. Rotor sheaves are greased daily ,twice on big days.The thing is the machine had the problem in its first season from new,so I do not think it has any thing do do with wear.I had a 1666 prior to this machine and treated it the same way. Never had a problem at all. I could count the number of rotor chokes on that machine on one hand. The 2366 with specialty rotor must have had about 20 in the same time.

First thing I would do is make sure is that the driver pulley on the right is not the one that is slipping. You would notice by the touch of your hand or a hand held temp guage, when you are running and noticing slip with rotor rpm readout. When you say belt tension is at max, that would tell me that your alignment would not be correct if rotor tower hadn't been changed when belt tightened. (step 1 proper belt tension, then alignment) I think it is a misconception that tightening belt tightener to left side of combine does anything. Just open the engine compartment door and visually look down at pulleys and belt to see if the look like they are in the same plane. Measure width of the outside of the pulleys (side with the belt and side that is open to belt shouldn't very by an 1_8". If it does then you need rebuilding of the sheaves. last make sure your ramp and rollers are in good shape, I seriously doubt that you could possibly have had this many bad springs.

had simlar problem, but the big neaprean bush that everything scrues_slides on inside the rotor spring, where the little greese hole were punched in to let the greese in to lubricate it, these holes had a bur on most holes. As the spring would tension the rotor belt, it wore gruves into the shaft that drove the rotor. Eventualy the rotor wouldn't drive or keep tension on the belt. Best of luck mate.

The shaft was checked by all the different mechanics involved. There doesnt appear to be any wear on it.

Todd I dont think any one has checked the driver pulley but I think that it is the driven pully causing the problem. When you feel the tension on the "old" spring( by lifting up the belt making the sheaves move) ,it has definately lost its tension. When I said that the belt was at its maximum tension I meant the seperator drive belt from the motor , the one with the window . The alignment om the rotor belt has been checked many times also.like you I seriosly doubt I could have had so many bad springs,but as each one is replaced with a new one it fails to keep its tension for much over 150 hours. Again I also had a 1666 for 1250 hours with a standard rotor and didn't have any trouble at all. In all that time I used only one rotor belt in 1000 hours .Only changed this as a precaution preseason . I have had four rotor belts on this one already. When havesting canola causes the most problems . The rotor alarm sensitivity is at 95% and it doesn't ever goe off untill the rotor is choked, much too late.