Combines Final drive shafts

If it's not too bad right now usually you can get by with replacing the couplers and save the splines on the shafts. If new couplers don't help its time for shafts also. Most combines with duals have a short stub shaft added to compensate for the addition of axle spacers that move the final drive out. Have heard of shafts and couplers breaking and stripping splines, but have not heard of or seen them blow up on the road or lock up. Gg

I would just change the cuplers there only about $35 a piece and it only takes 5 minutes just pull the pins out and slide the couplers in to the short shaft and it drops out. the reason for the short shaft is to access the trans without having to remove the final drives.

I had this problem once before making a few mods. combine wouldnt even climb a border before stripping out splines. Your couplers im sure are bad as well as the shafts, both wear evenly, it would be foolish not to change both. Dirt is the biggest factor with this wear broblem. Not to scare you but also my pinion shafts, for the final input had bad splines as well, couplers alone wont fix that so I rebuilt the finals while i was in there changin the pinion shafts.As far as lube I always always always now days on any drive system like this drill and put a zerk on the couplers in the middle and put a couple shots a day in each. They will last without a doubt longer than you will own the machine. My buddy with his old 7700 who is the original owner did this as soon as he purchased the machine and hasnt had any wearon the shafts and im talkin about a machine with atleast 15000 seperator hours and 25000 engine hours. Grease in thes area wont attract dirt which im sure had you concerned. mail me and let me know if your pinion shafts look bad.Good luck

Sort of a different subject, but I have had the coupler between the hydro and the transmission spin out in the mud. A good tip to fixing this is to take out the 2 bottom hydro bolts and replace with long ones, then take out the other bolts and slide the hydro out far enough to change the coupler. Saves having to unhook some of the hoses and lines, and, in some cases, the removal of the left tire.