C-120 Automatic Shifting working very hard.

[Chuck14025 9]

1975 C-120 Automatic, 12hp Kohler.       HARD SHIFTING PROBLEM

 

Starting to shift hard especially going into reverse. Also, shifting is not 'smooth'.  

Tried adjusting 'Friction Collar' looser and snugger. Made it a little better but then things locked up - it did not want to go into reverse.

Manually  pushed wheel to get tractor to go into reverse.

 

Could it be the:

   Cam on the neutral adjustment,

   Lubrication on the neutral adjustment,

   The transmission,

   The friction collar?

 

Suggestions welcome.

[JoeM 7,874]

A couple years ago a my friend experienced the same problem. One of the cam support socket head cap screws cam loose and backed out causing and was interfering with the hydro cam.

Might pay to take a closer look there.

One safety tip. Anytime I mess with those hydro adjustments I put the rear wheel up on jack stands for testing.

[daveoman1966 3,752]

You MAY also have a problem here....pretty common.  

[Chuck14025 9]

Thanks Dave and Joe,

 

I'll put the rear axle up on blocks to make sure the tractor doesn't run me down.

 

The tractor is stuck with the control lever forward. It will not come out of gear.

 

I don't find a broken weld, everything is intact, but I can't see the " cam support socket head cap screws " yet.
 

I have the original parts manual but can't see the 'socket head cap screw' listed. 1.  Can anyone help with that issue.

 

2.  Also, if I have to take the tractor apart to get at the cam mechanism, does anyone know of on-line instructions and diagrams on where to start?

[Searcher60 209]

I'd wager the rod that runs thru the friction collar is seized. If so, you need to carefully get it apart, and that ain't easy if it is seized. That is why the welds break. 

[chip61 658]

1 hour ago, Searcher60 said:

I'd wager the rod that runs thru the friction collar is seized. If so, you need to carefully get it apart, and that ain't easy if it is seized. That is why the welds break. 

 

Mine is seized-been working with PB Blaster, vice grips and a 5/8" wrench-I've got it to move almost a 1/4 turn now-long way to go. I think I'm going to have to heat it to get it where I can get it apart to clean it.

[daveoman1966 3,752]

I ahve to add another pic of the frictioin control mechanism....  watch the little WOODRUFF key when taking this stuff apart.  You need to remove the woodruff key BEFORE taking out the shaft.    

[Chuck14025 9]

THANK YOU ALL for all the good advice.

The ACTUAL problem turns out to be …..

The CAM BLOCK PIN is hitting the CAM FOLLOWER ARM.

This is the location where the result of moving the shift lever back and forth engages the cam that shifts the transmission. I was focused on the FRICTION CONTROL which turns out to not be the problem.

The problem from the start is the CAM BLOCK PIN hitting the CAM FOLLOWER ARM which indicates something very major has moved at least 1/16” of an inch.

1.      It might be:

      1. The tractor body parts that house the SPEED & DIRECTIONAL CONTROL LINKAGE ASSEMBLY (the shifting assembly) or

2.      2. The REAR AXLE ASSEMBLY or

3.      3. Something has come loose or broke or

4.      4. A frame part has worn enough to allow something to slide 1/16” of an inch.

      5. Something else   ????

YOUR THOUGHTS on all the places to check would be very appreciated as always.

[Sarge 3,463]

Look very closely at the rear plate under the rear of the frame where the transmission is bolted to it - probably cracked/broken from hard work/abuse . It's a common thing with these frames and the C's had braces to help with this , but if they are pushed hard enough or rammed into solid objects that plate can give up . What happens next is it usually loses most of the travel on the friction cam plastic section , so you lose forward travel speed and if bad enough you'll lose reverse ability altogether due to the transmission being tipped at an angle . I've re-worked the rear plate in the 1277 twice already , now the plate is shattered and done - have to cut it off and make a whole new one along with more bracing - yes, I work that tractor that hard . Loaded rear tires w/weights and chains will do some damage if pushed , lol - but I have the ability to repair/rebuild it so it's no big deal here ...

 

With the rear fender pan removed , it's easier to see the transmission mounting plate and rear of the frame - also it's not too hard to remove the trans once the frame is supported with jack stands - the only trick being to keep it from tipping off a garage jack since it's so nose heavy due to the pump and shape of the trans case . I usually leave the rear tires on them and just roll the whole thing back , access and repair the damaged frame , then reassemble it and go back to work .

 

Sarge

[Chuck14025 9]

Thank you very much Sarge.

I have a 1975 Parts Manual. I can't find the 'plate' you refer to. Can you give me more specific direction on its location?

Is there a way to lubricate the rod that holds the FRICTION COLLAR assembly to prevent it from seizing?

[pfrederi 17,741]

The plate he is talking about is the rear end of the frame has 4 bolts that go through it into the tranny

[Chuck14025 9]

Thank you.

Is the plate the actual frame or a separate piece? Is it vertical or horizontal? And, if you would, where can I find a copy of the parts diagram you posted?

Thanks again for your help.

[pfrederi 17,741]

 

[daveoman1966 3,752]

Here is the method I use to repair the cracks in the FRAME PLATE, using two 1/4" or 5/16 Angle Iron measured 2x2x6 .  These get bolted to the SIDE of the plate and the the base of it....where the orginal 4 trans bolts are.   If you just bolt a thick plate onto the back of the crqacked frame plkate, it will LIKELY just crack again at the corners / sides.  This method precludes that event and reinforces the corners.

Just work on one side at a time  to avoid collamity.   Just find 4 bolts about 1/4 or 5/16 longer than original...but not too long.  The 8 side bolts are 3/8 with Nylok nuts on them.    

 

[Chuck14025 9]

For the benefit of the next 'newbie' who encounters the same problem, the plate is 'vertical', attached to the rear end of the main frame.

 

OK Dave, excellent photos, excellent solution. How soon can you have custom angle iron ready for my C-120? I'm only half joking. You make 'em, I'll buy 'em.

I hope you saved a pattern. I'd bet you could sell several of these -- getting paid well for your time and materials.

 

Am I reading it right that they could be installed one at a time on each side without pulling the whole transmission away from the frame?

 

I'm only 2 hours north of you so I could pick mine up tomorrow --- don't want to rush you or anything.  Bet you could be a hero to several guys in the same predicament I'm in.