Combines Wobble box advice needed

1_ Is the knife bar vibrating back and forthIJ There should be almost no visible side ways movement in the knife bar when operating at full speed. If there is you may have a broken knuckle on the knife bar stabiliser under the feather sheets. 2 _ If the wobble box is making a loud click or clonk at the end of each stroke then the bearings on the front and back of the main bearing box need to have shims removed which should take less than an hour. 3 _ The spigot bearing under the main bearing housing and at the bottom of the wobble box may be shot which will allows the knife drive arm and sickle head to flop around and really mess things up. It doesn't need much movement in this spigot bearing to start to cause all sorts of trouble. This spigot bearing needs to be kept in very good order as it takes a large part of the thrust needed to drive the sickle and it is critical in locating the main bearing housing of the knife head. 4 _ Spigot bearing plates may possibly be badly worn allowing the spigot bearing to flop around. The only way we can prevent serious and rapid wear on these plates is to set the wobble box up on the bench and locktite the plates and round spigot bearing together. It usually lasts 3 or 4 years before we have to touch it again after doing this. 5 _ For long term smooth operation of the wobble box and the entire knife and to really minimise maintenance on the wobble box, install a flywheel on the wobble box drive pulley as well as on the counter shaft behind the head as in Heddy's Hyper Mods in the Hyper Mods section.

I don't know that I can address your specific issues, but we had problems with our box on an 830 flex. We had mostly problems with knifehead breakage even with the heavy head. I replced the OEM box with the SCH Pro Drive and it is a major improvement. No more vibration or broken knifeheads and the speed of cut is awesome. With our old drive 5mph was max unless you wanted to run a few over. We have run 6 this year and don't miss a one. So my advice is don't spend much on the old drive without considering the prodrive.

Replaced the bearings in the wobble box and got going again - it is better but still seems to be some shake in the belt - I think the shock absorber on the belt may be shot - I have one ordered. When we finish I think I'm going to try the flywheel idea for next season. Also looking at the the SCH Pro-Drive box - maybe get one for my grain head as well, since its got a few problems of its own. Thanks for all the help!

Before we came up with the flywheel idea, the wobble box belt drive shock absorber used to get that hot from vibrating that we could not put our hand on it. We also had to replace it every couple of years. Since installing the wobble box flywheel plus the counter shaft flywheel, the shocker has a movement of about 3mms, barely enough to break the dust that collects around the shaft. The wobble box drive belt just sits there with very little vibration unlike the pre-flywheel days when you could barely see it due to vibration. This belt only needs to be replaced every few years now instead of a couple each year.