Reversing Rear PTO Shafts

[chchatzop]

Hello to all. I am new to the forums so excuse me if I have any errors in my posting format or any language errors as I'm not a native english speaker.

I bought some weeks ago a used John Deere 6920S tractor, 2003 model. The PTO shaft of this model "has 2 sides". One is 6-Splines 540rpm and the other is 21-Splines 1000rpm. When I bought it, the previous owner had the 6-splines one installed while I want to use a machine operating at 1000rpm. So I tried to follow the manual's instructions on how to reverse it. I don't know if I'm allowed to post links to other sites but here is the link of the manual's topic:

OMAL152775: 6520, 6620, 6820, 6920 and 6920S Tractors, Block File: LX_OZAPF008927_19_01DEC95.htm

The problem is that there is no groove to attatch the snap ring at, at the side of the 1000rpm. The 540rpm side though has the groove (you can see it at the 2nd picture of the manual page). Without that snap ring, the PTO shaft doesnt lock and can be removed even by hand. I tried alot to install the snap ring at the 1000 rpm side but no luck. I am wondering if the shaft i have is from another model or something.

Has anyone faced this problem? Anyone can help me with info or suggestions? Thank you in advance!!

 

[kennyd]

Welcome to TBN

I can't really help with your problem, but just wanted to say your English seems perfect (better than some who are born in the US) and linking to any manufactures website is perfectly acceptable.

 

[JD755]

Agree your English is excellent. Welcome.

Are you saying that without the groove, the snap ring cannot be squeezed closed enough on the shaft to fit into the hole? If so sounds like you have a real show stopper. Does the other side also have the flat that can line up with the ends of the snap ring?

 

[atschirner]

I have never done this operation but from the manual it appears as the snap ring is expanding into the housing to retain the shaft. Slot B, in the 540 side of the shaft, is there to allow clearance to contract the diameter of the snap ring for removal. On the 1000 RPM side the shaft meets square to the drive gear so no slot is required to compress the snap ring for removal.

Hope this helps you.

 

[JD755]

I have never done this operation but from the manual it appears as the snap ring is expanding into the housing to retain the shaft. Slot B, in the 540 side of the shaft, is there to allow clearance to contract the diameter of the snap ring for removal. On the 1000 RPM side the shaft meets square to the drive gear so no slot is required to compress the snap ring for removal.

Hope this helps you.

It is not clear from the picture that it meets flush on the far side. That is why I asked about the flat.

 

[chchatzop]

Agree your English is excellent. Welcome.

Are you saying that without the groove, the snap ring cannot be squeezed closed enough on the shaft to fit into the hole? If so sounds like you have a real show stopper. Does the other side also have the flat that can line up with the ends of the snap ring?

Sorry for the slow reply.
No, at the 1000rpm side there is no such area like that shown at figure B and most importantly it doesnt have that "protuberance" at the end of the flat area that prevents the ring from slipping together with the shaft outside when someone pulls the shaft. I tried to squeeze it close enough as you say but when i tried to test it I could even remove the shaft pulling it by hand.
I know someone else has the same tractor as me at a village near mine so I will go and check his shaft.
Another thought i have is to make the 540rpm side some milimeters shorter so when it is inside the tractor (so the 1000rpm side is outside for usage) it can go abit further inside so the ring has space to fit inside and probably lock there.

Thank you all for your suggestions and help!

 

[mustangsallysdad]

There's nothing wrong with your English...you should be proud...I've had more trouble understanding posts by native English speakers.

 

[SPYDERLK]

Sorry for the slow reply.
No, at the 1000rpm side there is no such area like that shown at figure B and most importantly it doesnt have that "protuberance" at the end of the flat area that prevents the ring from slipping together with the shaft outside when someone pulls the shaft. I tried to squeeze it close enough as you say but when i tried to test it I could even remove the shaft pulling it by hand.
I know someone else has the same tractor as me at a village near mine so I will go and check his shaft.
Another thought i have is to make the 540rpm side some milimeters shorter so when it is inside the tractor (so the 1000rpm side is outside for usage) it can go abit further inside so the ring has space to fit inside and probably lock there.

Thank you all for your suggestions and help!

When you reverse the shaft you have to push it in firmly. On my Mahindra 7520 the end of the shaft pushes a rod inside to shift to the different gear ratio. Try pushing in and rotating a bit so the gears line up. It should go in a little further and give enuf room for the snap ring to engage.
larry
oops ... from the picture it looks as if that internal rod is pushed for the slow pto speed and released via that clearance hole on the 6spline end to shift to high speed. Maybe the hole on yours isnt quite big enuf. :confused2:

 

[jd110]

The snap ring should fit in the groove that is in the socket where the shaft is inserted. The groove on the shaft itself does not hold it in. If the shaft will not go in far enough, then you either have bad/incorrect shaft, or there is something in the splines that won't let it in far enough. If another tractor is nearby, I would take your shaft over there and compare it to yours, and try yours in his tractor.

 

[chchatzop]

Thank you jd110. I was thinking that the groove on the shaft doesnt hold it and it's just the groove at the socket and its good that you confirmed it. So now i only have to check if there is something in the socket that prevents the shaft from going deep in or if the shaft is from another model/tractor. Thanks again!