Combines 760 variable drive problems

Hello I had this same problem a few years ago on my 750 same set up. Now I am testing my memory here but there was a update I put in that Variator that helped and also the sheaves I had turned down on the edges of the pulley there was a groove in the sheaves so when you would run your variable speed the sides of the belts were being woren riding on that rough part of the sheaves. Now this was a number of years ago but if I remember it solved the problem. Did you make a slide out of a steel fence post and a chain and hook to slide that variator out on. Makes all the difference in the world. Good luck stressful SOB when that goes on.

Thanks, I have thought of that and had checked the sides of the variable and they seem OK. However, I will look at them again in the morning. It seems like the belt edges are suffering first and the belt is running very warm, like friction is a factor. As for replacing the belt, I have that down to a science. I can change it in an hour. I shaped a 2x6 to fit at the back and bolt it there and use a porta power hydralic jack on the front to raise and lower the variable just right to get the guides back in the channels they belong in. Again, thanks for your views. Duane Jones

We run a silver cab 760 with the 4 speed and variable belt drive - we would expect at least 3000acres from a set of transmission belts and usually take them off while they are still in good visual condition. You must have a serious problem of misalignment _ crook bearings _ or failed tensioning under load ! . Its not a problem area on my machine! You might need to get someone to drive while you ride on the step and see what is going on but its for sure something seriously bad is happening in that drive line to cause this amount of belt wear.

Thanks, Greyhawk for the views. The belts appear to be running in alignment. As to tension, Massey recommends the spring tension bolts are to be tightened as tight as possible. I have done that and the belts break sooner. Tonight when I brought the machine home and felt the belts, the top one was much hotter than the bottom one. Do you suppose the top one is slippingIJ Incidentally, the top one always is the one to break. Thanks, Duane Jones

we had a bunch of trouble on a deere variable drive and it was a vibration in the driveshaft coming from the engine -M.

I would almost bet that the fork holding the shieve is out of alignment. even if it appears to be straight. This was a common problem on 510s

Thanks for the idea, riceman. I will look at that. I think it is OK though, but any help is appreciated on this thing.

Thanks, mkola. I have about came to that conclusion. This afternoon, I have a pronounced vibration and it seems to be in the shaft from the engine. It is raining here now, so maybe tomorrow I will see what kind of nightmare that will be to get to that shaft.

I had the same problem on our 860, the slide inside the variator was worn and the sheave was not running true.Something to check out anyway.

Thanks Shadow, I have replaced the slide last year. I think I am going to have to address a vibration in the top input shaft. It might be the problem. However, every time I think I have found the problem, guess again. Duane