Combines pto gearbox

[rod]

If you have ever plugged the rotor and killed your tractor then chances are you have started the problem. What usually happens is the long input shaft bends, throws off the clearance on the gears and then they disentegrate. You can take the covers off and measure clearances between the gears is one possible way to check. I had a guy tell me to drill a hole above the input shaft in the housing and see if the long shaft is bent by using a micrometer or even something like a welding rod with a mark on it resting on the shaft while you turn it slowly should show if it is bent. Then thread the hole and screw in a plug. Another rule of thumb is that if you have less than 200 hp in front you may never hurt the gearbox and only a bearing wearing out would cause trouble. I also know that the Case dealer at Chamberlain, Sk will repair only what is needed and will straighten the shaft once instead of a total rebuild. $1500 instead of $5000. This will probably cause some questions so ask them. We ran 2 1482's for 10 years.

 

[Big_Al]

We have a 2188 that was giving us problems last fall with rotor speed it would run at proper RPM when you were in light crop once you got into heavy going the rotor speed would drop and would not come back up. My dealer said it was the clutches in the PTO changed them no different then he said it was the torque sensor busings changed them no different. I then put a post on this site and got the info. that it could be the gears in the PTO assembly that was the problem $6000.00 later it works like new.

 

[bigjim]

Dont know how the pto gears could cause this problem unless they were stripped out and then they should slip all the time. My bet is that problem was misdiagnosed and something else was repaired at the same time and that was what got you going again.

 

[Rotor_man]

Had the same problem with a 1480. It would not maintain rotor rpm under heavy load and was hard on pto belts. We replaced the slightly worn pto pulley thinking that was the problem. It finally got to the point that it would tear those $150 pto belts like they were rotten twine.went through 4 of them in as many days. We had to make a several hundred mile trip the next day and decided to ask one of several IH dealers along the route what they thought could be the problem.When I told them it couldn't maintain rotor rpm and was tearing pto belts.the immediate answer was that the gears were bad in the pto. I thought this was rediculous,the gears seemed to make no noise and I couldn't understand how they could make the belts slip, so I stopped a 2 more dealers along the route. Asked the same question and got the same answer 3 times. The last guy said to drain the pto and inspect the gears through the top cover. As the man said,the gears were worn and starting to flake off teeth. The failing gears woukd set up such a vibration in the pto pulley that it would slip and finally tear the belts. We replaced the gears and input shaft in the pto and everything was back to normal. I would say that what the dealer told big Jim was dead on right.

 

[Rotor_Man]

I run a 1482 with a small 225 engine HP 4WD tractor I did manage to break a pto gearcase because of the soft bolts they use to bolt the box together. I had to tighten those bolts several times per season as they seemed to loosen to the point that grease leaks would develop. I found out the hard way that the bolts were stretching instead of loosning. Finally popped the heads off 2 bolts and the rest of the bolts and case couldn't carry the load,broke the inboard case. I replaced the case and all the bolts with grade 8 bolts. No more loose bolts,no more gearbox trouble for the last 10 years although this lesson cost me $600.