Combines ClUTCH SHAFT VIBRATIONIJIJ

[John]

Had something very similar on my 82 N6. I first had the vibration noticable then it started to tear up the belts that run the head and accel. rolls. Finally found that the previous owner had had a couple "hard stops" and bend the driver end(ever so slightly) of the MAIN CROSS_ClUTCH shaft. Replaced the expensive shaft and bearings(dealer wouldn't do just the shaft)and haven't had any problems since. The clutch packs can also give some problems like that when they are tired of out of adjustmnet. And of course you have to crawl inside the combine to work on these units. They can be seen from the left front but not easily reached. Many N6_7's have had bent or broken cross shafts according to the 2 local salvage yards. One yard has a beautiful N7 with just a broken cross shaft in it.

 

[Aussie]

I would be looking at a bent mainshaft too.

 

[DAB]

Thanks for the comments guys. That leads me to a couple more questions. When you say the clutch_crossshaft, or the main shaft, you are talking about the right hand, or the longer of the two shafts rightIJ My old service manual calls them left hand and right hand clutch shafts, so I want to make sure we are on the same track and I'm looking at the proper one. Also, in my case, the vibration is present both when the seperator is or is not engaged. If the right hand shaft was bent, would it still cause a vibration when it isn't turningIJ or could it throw things out of alignment enough to cause a vibration anywayIJ Thanks again! DAB

 

[John]

The shaft that was bad in my N6 was the one that goes across the entire machine, 4'-5' long and between 2"-3" in diameter. The left tip was bent on mine, the main engine_hydro belt end with the clutch pack attached to it. That is also the shaft that is broken on the N7 in the local salvage yard. Probably the most expensive shaft in the machine, costs more than a crankshaft in the 670I(426ci)engine. Had to watch close and measure the wobble in mine to know that it was bent, but it put out one heck of a harmonic vibration and jumped or tore up belts.

 

[Dan]

I would make sure dirt is cleaned from ID of hydro idler and hydro driven pulley. Replace the idler if all clean for it may of bent for some reason. If you take left mainshaft back out be sure to check the torque on nut that holds hub with pegs in it. I have seen some machines where that nut was not up to torque so hub started wobbleing on shaft which could ruin shaft and hub. Hub should be a just miss fit on shaft with no wobbleing. I believe a problem with right mainshaft and or hub would give you vibration mainly with seperator engaged. Good luck.

 

[Glenn]

I have seen some clutch shafts that have been mis-aligned when everything has been put back together. It helps if you make a boss with an extended shaft to find where centre is on the outside of the machine, where the bearing housing bolts on. The boss fits into where the spherical bearing goes. Sometimes the mounting holes have to be elongated to reduce pressure.