Cadet 123 hydro speed control

[Fred's 123]

I'm looking at this again, and it would appear building the necessary areas with weld could be more difficult than one might think. I've filled round holes, which is not so difficult, as the weld puddle is contained by the base metal. However, when building a long edge of the trunion slot, even when backed by copper or brass, there's not much there to contain the puddle and hold it at uniform thickness prior to solidifying. I'm not convinced this is easier than just lopping it off and welding the new repair slot in its place.

[Matt G.]

It is easier than you would think to weld in the corners. I am not a very good nor experienced welder, and I didn't find it that difficult. You don't even need the copper backer, just bump the corners a bit and grind (or file, if you used a MIG welder) it back into shape. It's even easier to do with the hydro out of the transaxle and on the bench. Since you probably need to replace the cork gasket between the hydro and transaxle, you might as well make this easy on yourself...

I have never been nuts about that repair piece...while several people have successfully welded it on, you're throwing a LOT of heat into that trunion shaft, and a wet rag may not be enough to keep the seal cool if you are not careful. I'd at least try welding up the corners first, as you've got nothing to lose if you're going to cut it off anyway. Once you cut it off you are at the point of no return.

[Fred's 123]

Cool. Thanks for the advice. I'll wire up a 220v receptacle today, and get that mig running. Got no gas at the moment, so I'll just run flux-core wire.

[CHWNY]

Fred's123, If I were to do this repair, I would clean the area well, use a backing of copper or aluminium what ever you have the thicker the better. This backer will keep the wire from shooting through, contain the weld and making for less cleanup and act as a heat sink. Set your welder a "little" hotter than you normally would for the welded metal this will give good penetration with less heat. Be sure you have a Good ground! Snip the wire for clean start and hit the area to be filled as if you were Tacking it. I think you will be happy with the results!

[Fred's 123]

It is done! The repair was easier than I anticipated, even without the aid of air tools. Squashed a 3/4" copper pipe coupling to make a flat backer, touched up the corners with the MIG, then ran one bead down the outer and forward sides of the slot. Filed it to 1.200" x 0.765" (±0.001"), and reassembled. I took the opportunity to shim the damper plate to remove any wobble (mine took one 0.005" shim washer), and bent the trunion about 1/16" to center the springs better on the damper plate.

Hydro is already installed, and tractor is ready to be re-coupled.

Thanks!

[darkminion_17]

You should give yourself a pat on the back for a job well done!!

[Methos]

Originally Posted by darkminion_17

You should give yourself a pat on the back for a job well done!!

Great job! I knew you could do it!

[Fred's 123]

New damper plate installed, and shimmed for minimum wobble. New cam plate installed, and also shimmed for minimum wobble. Had to cut a little length off the post on the damper plate, which intersects the slot in the cam plate, as the Cub 123 has no clearance for the longer post length used on the newer damper plates. Each fitting is filed, lapped, and greased to work with precision, and I don't think this cub was set up nearly so nicely when new. Hopefully it pays off.

So, I recoupled the tractor last night, and I did notice a bit of Hytran tripping down the front of the diff housing when I tipped the rear forward to recouple. Hopefully it was just the bit of fluid I spilled when I primed and reinstalled the hydro with the new cork gasket. I'd hate to find another leak after all this work!

Will try to fill rear and perform operation neutral adjust tonight, if I find time.

[Matt G.]

You won't want to hear this, but the grease needs to go. Grass and dust and all sorts of crap will stick to the linkage and wear it out faster. If you must lubricate it, use some sort of dry lube.

[Fred's 123]

I debated on the lube myself, figuring that was a likelihood, but went with a very lightweight NLGI-1 grease for a few reasons:

1. The old guy from whom I bought the tractor greased these components once per season, and they've held up remarkably well. Aside from the worn spring perch on the trunnions, the only component he did not grease, the cam and damper plate showed almost zero wear after 45 years of pretty heavy and dirty use.

2. My iH service manual instructs to lube the cam slot with "chassis lube".

3. Since these components are supposed to be left unpainted, I wanted some form of rust inhibition.

I spoke with the previous owner about this, and he said he used very light grease, such as assembly lube, which is where I got the idea. His figuring on that probably was along the lines that it would be less "sticky" than a standard mid-weight grease.