Transmission cover removal

[284 International]

I finally managed to fish out the pieces of the broken shifter fork. I drained the hydraulic fluid, and it was absolutely disgusting. Literally: it was a rancid mixture that smelled like formaldehyde, looked like puss, and generally reminded me of my time in the cadaver lab. Ugh.


I feel sorry for the guys who at the parts store who are going to drain this stuff into their tank. I'm going to find out when their pickup dates are so it doesn't make their store reek. It had coated the filter screen with a layer of nastiness that reeked worse than the fluid:

The biggest piece was at the far back of the transmission case, somewhere under the PTO shaft. It looks like a broken off piece of shifter fork:

After some more fishing, I found remnants of the spring, washer and circlip that fit onto the bottom of the shift lever and knob and, happily, the broken off tip of the fork, which sits nicely onto the larger piece:

[

Work is, as usual, getting in the way of my tractor tinkering, so it will be a bit yet before I can weld the pieces together and get everything ground down smooth again. It looks like the shifter forks are cast iron, does anybody know for sure? I was planning to use Ferroweld rod on it, but would appreciate others' experiences in welding on these types of parts, good or bad.

 

[winston1]

If that is the first and second gear fork Yanmar Tractor Parts: SHIFT FORK 1ST & 2ND GEAR you can buy a bunch of welding rods.

 

[284 International]

It's the reverse shift fork, so not as steep, but still worth buying the rod and spending some time to make these pieces work!

 

[Domush]

If it is cast iron, I think nickel rods are best to join them, if I'm not mistaken. My neighbor owns a welding shop and that is what he says he uses on cast iron. I can ask him tomorrow to make sure.

Definitely worth attempting the repair. It is metal.. it always goes back together

 

[Car Doc]

I am going on the record by saying dont weld it.

If it breaks (it will) and you aren't so lucky then and end putting the bottom end in that tranny it will be a heck of a lot more money and effort than just putting in a new fork and forget about it, every shift you will be wondering is this the last one. my ,02

Anything can be repaired and I know you will do as good a job as can be done its just is it really worth doing especially cast and in a critical area with a lot of lateral forces against it I dont think so in any stretch of the imagination.

If it was outside and if it broke again it just inconvenienced me so be it but lighting a fuse by welding it and its inside a trans is insane. my .02

It isn't the last fork in existence so imho it isn't a candidate for repair. ymmv as always

 

[Domush]

It looks like the shifter forks are cast iron, does anybody know for sure?

Easiest way to tell if it is cast steel or cast iron is to grind it (which you need to do before welding it, anyhow). Cast iron will have orange sparks, and not many of them at that. Steel will have yellow-white sparks which fly everywhere.

If it is cast steel, a standard MIG or TIG will do just dandy. An arc welder will be needed (special rod used) for cast iron.

Be sure to grind a small angle (1/3 material) on each side (so 1/3 material remains in the center) of where the pieces connect, so the weld joins the two pieces natively and semi-flush (a little above flush is what you want here, to be safe), rather than making a "weld band-aid" on both sides with little to no attachment in the center of the joint. If the piece is 1/4" or less thick, you are fine just making a tiny groove (1/16" on each side) instead of digging into the material, as most welders, including cheapy home ones, will weld 1/8" steel completely through, so long as you don't rush the weld. Practice on a piece of scrap before you do it, just to be sure you are dialed in, if you are nervous.

You may already know most of this, but thought I'd play it safe.

I'd also recommend quenching the part right after welding it, so it will stiffen it. I'm guessing here, but I'd think a shift fork needs to be more stiff and less flexible than your average steel part. Worked out well on my 4WD shift dog I recently repaired.

Don't be afraid to cut it off if you don't weld it perfect. Perfect and re-re-re-welded is better than close enough and pretty in this case. Time is free (mostly), so take you time and do it right. I always want to rush through a weld, but then wish I didn't when I'm disassembling the entire assembly to re-weld a rush job.

As always, don't forget to take before and after photos (more is better!), as no DIY job is complete without photos. :thumbsup:

 

[California]

I'm with Car Doc on this one. I would buy the fork.

 

[winston1]

I am right in the middle. I would probably try the welding route and judge it once completed. Sometimes after doing something like this you can gain or loose confidence in the results. :thumbsup: