4020 pto problem

[Mississippi deere]

Hello guys I just found this site, looks like a pretty good source of info.

Maybe somebody can give a clue as to what is happening with my machine. I have a 68 4020 synchro, The last time I used the pto it worked fine, but this time when I started to engage the my clipper it just lugged the engine down. Well after unhooking and reconnecting the implement I found that the prob was in fact the tractor. The pto while not engaged will turn about 3/4 revolution then stop, when the engine is dead and the pto is engaged the pto will not turn at all. Has any one had this type of problem before ? Or any ideas? When you spin the pto with engine off it stops abruply and has a metal click noise up near where the engage rod goes down into the tractor (under the dash and Steering wheel). Thanks

 

[bison]

i'm thinking the PTO brake is broken and jammed,or a brg seized in the pto drive line.
whith stopped engine and pto engaged,it is not suppose to freewheel. or shifter pin in pto shaft stuck or bend,keeping both pto speeds engaged at the same time
Will pto disengaged turn backwards?

 

[Mississippi deere]

Only for the same distance, 3/4 turn.

When this initially happened and I ruled out the implement, I picked up the bushhog and spun the blades with my hand, pto not engaged of couse. This freed it after 2 attempts, well,I started to go to work engaged the pto with bushhog attached, and it functioned correctly for about 10 feet, then , SNAP, it twisted the shaft from the pto shaft to the gearbox on my cutter. 30 Min later I had that repaired, and I did not try that again.

 

[bison]

I think when you broke that drive shaft,the backlash of the impact took out a couple of teeth on the PTO drive gears.so now they dont mesh no more but lock on to each other,that would explain the 3/4 turn limit both ways.

 

[Tx Jim]

There is no shifter pin on a 4020 pto that can engage both speeds at the same time as someone posted. The speed change on pto is at rear accomplished by changing stub shafts as each speed drives from a different size gear. With engine off pto shaft should turn if lever is moved up slightly to relieve pto brake pressure if a brg isn't bad.

 

[Glen D Anderson]

Note: he was having troubles with the PTO on the tractor BEFORE he snapped the drive-shaft for the mower............or so the post reads...........

 

[bison]

where in my post did i suggest that?

You should READ before commenting

 

[bison]

Ah,i did not read right either.

something is getting between the gears to lock up like that,a couple missing teeth could do that.could have happened bushhogging anyway.
these things are not that driveline friendly.

 

[Mississippi deere]

Is there any way to inspect things before the dreaded split?

 

[bison]

only thing you can try is to swap to 1000 pto and see if it still locks,if it does'nt then it is 540 gear affected most, but no way of telling how bad the rest looks other than split and find out.Split between clutch housing and transmission. I cant think of any thing else to check.
basic set up is input shaft from clutch to 2 speed gear setup with shiftcollar and fork, and brake cone and output shaft to rear

 

[Tx Jim]

bison,
May I ask what shiftcollar & fork you are referring to. I don't remember this on a 4020 pto but a lot of water has run under the bridge since I looked at one.
Thanks

 

[bison]

Now you got me thinking,It has been a while since I got any apart,am i mixing up series here? I got no manuals to consult either.