Rear driveshaft coupler- 122

[jbrewer]

Hello OCC

I need to replace the rear driveshaft coupler on my 122. Do I need to split the tractor (or move the engine forward a half inch or so) to get it out? I know I need to remove the spirol pin(s).


(Edit, pins are out. Coupler still hung up on the input shaft end. Someone has been in here before me on the same mission I now see)



Splitting the tractor might be less of a PITA but not sure either is needed and I am sure neither is easy.




Thanks for your advice

John

[CubDieselFan]

Moving the engine forward may be the easiest of the options?

[darkminion_17]

Remove the grill, lay it on a milk crate or whatever, then you will have more room to slide the motor forward so you can remove the clutch. Then split the tractor, this way you can see how much damage there is to the shaft.

[jbrewer]

Originally Posted by darkminion_17

Remove the grill, lay it on a milk crate or whatever, then you will have more room to slide the motor forward so you can remove the clutch. Then split the tractor, this way you can see how much damage there is to the shaft.

You're saying I have to do BOTH?


I need a nap.....

[darkminion_17]

ZZZZZzzzz ok if you lay under the tractor you can remove the coupler.

[finsruskw]

Either that or cut the tunnel open (Geesh, I hope not!!) or stand the unit up on it's tail somehow.

Do you have a set of roll pin punches and a new coupler?
You need to support the nose of the transmission and/or the coupler to drive the pins out or risk damage to the input shaft bearing and seal.
No one said this was going to be easy.
NF fans have to be a dedicated bunch!!

[jbrewer]

I did get both roll pins out . I have a good assortment of punches and what I have used before for this is a long snout punch aimed down through the creeper slot in the tunnel. I had a 2x4 wedged under the coupler to help absorb the hammering (one came out easy , one was more challenging.

I think the inside of the old coupler is galled which is preventing it from sliding forward on the driveshaft. This is going to be tricky.

I think I'll just split the tractor (6 bolts?) then I can stand the rear end up and use a puller to get the old coupler off. I suspect what I find will not be pretty but I have no spare input shaft, but I do have a new coupler.


No way I'm going to cut up the tunnel! :-)

[jbrewer]

Came apart without huge drama... just some jack stand rodeo.


Have fenders and pan off now which will slow me down as *everything* in this tractor is rusty and will need at least some wire wheel and rust reformer. Great day to be outside. I won't be able to say that in a month :-)


Input shaft is not bad. Coupler was bad! New one looks great (Thank you Jeff!)

[jbrewer]

So everything is back together but there's a problem.


I can't get the clutch to disengage. When I press the pedal, the shaft stays turning. Prior to replacing the rear coupler this worked fine.

Some facts:

• When I adjust the clutch, I can see that the disk is free of the pressure plate and flywheel and I can move it on the locating pins.

• The driveshaft and rear coupler are new. The clutch and pressure plate are new (all a few months old)

The next two things I believe are related

• The old rear coupler was wallowed out and allowed about .25 inch of wobble in the driveshaft at the rear coupler end. It was acting more as a universal joint than a rigid coupler
• The new driveshaft does not line up perfectly with the rear coupler. I doubt the old one did either. It lines up fine vertically, but not horizontally. The offset is controlled by the engine end (I can see the offset with the tractor split).

Is it possible that the axial offset is somehow preventing the clutch from releasing? My guess is "yes" but I just don't see how, as if I push the brake/clutch pedal in and set the "parking brake" I can easily move the disk on the locating fingers of the clutch assembly (engine off of course)

[darkminion_17]

Maybe the coupler is on backwards.... Do you have the anti rattle springs on the clutch?