Cast Iron Transmission Housing Repair

[drujinin]

A hobby farmer broke a chunk of casting out of the transmission housing on his tractor. Its a part where the 3 point lift/hitch assembly goes on the bottom/back. Which translates to always having a pulling force on it. I'm thinking of grooving/veeing, preheating, using 66 Ni-Rod in short welds to put this piece back in/on, with post heating till I get bored of trying to keep it warm. Two reqirements are to stop transmission oil from leaking out after weld and ability to hold the stress of implements pulling on it.
Any ideas? Opinions? Help?
drujinin

[canoecruiser]

This probably isn't the answer you're looking for, but why did it break in the first place? Was there a bubble or void in the metal where it came apart? Under-engineered? Abuse? It's important since you (and the farmer) don't want it to break again. If it wasn't strong enough to begin with it won't be any stronger, and may not be 100% as strong, after repair without some type of reinforcing to spread the stresses over a larger area.

Lighter-framed tractors like my compact New Holland aren't built for 3-point-mount backhoes for example. Shame as I found a sweet one to complement the loader on the front. Like the dealer said, just 'cause it fits doesn't mean you're good to go......

[Sandy]

Yeh, not that uncommon of an incident. 1st order of business on the hobby tractors should be to rebuild that bracket that serves as the 3rd point attachment. Add some tabs, ears or whatever you gotta do to spread the load out to more bolts back there. It doesn't have to be a work of art, just get it done before you start pretending you can rip stumps out with a box blade. Bust that cast housing and you're behind in the game.

[drujinin]

Time is on my side for this repair, I could strip it down this winter and repair it inside and out. He has use of my tractor right now.
BUT!
I'm thinking that all I will be able to do is remove all the offending junk whilst studying its attaching points. Then repair the hole to create a no-leak situation. Fab up some new mechanically mounted re-inforcing plates to spread the "Stress".
The second choice pays me faster which prevents his wife from talking him into trading it in before I fix it. :D

[george md]

It wouldn't be a kabota would it ? It seems that when they have a
rear blade on and back up hard against something and push the 3pt
up past its limit ,it jerks the 3rd pt out of the top section of the rear.

Take it apart ,strip it , and do a oven preheat and O/A cast iron
repair . Have done a few .

george

[usmcpop]

Hey, George, good to see you posting.

[george md]

Yes , it's been a while sice I've been here , been busy. Built a real
office for the shop , broke ankle , back got so bad last summer that
I could not walk or stand ,got that fixed oh what a relief . Was a
bear trying to run a lathe or mill from a stool . Cast iron came to a
stop for a while , and boy did the jobs backup , still working on some
of them.
Got a big block chevy in from somewhere in the midwest to fix crack
to starts in the rear cam bore and goes toward the main bore , also
a 40's gmc 6 cyl that is suffering from a dose of hard water ( just
above the oil gallery and plus all the regular work , pair of Mack
4 valve heads in today ,one dropped a valve and needs some repair
on the face , put them in the hot tank a few minutes ago. Going to
be a real busy week , wanted to go to kinzers tractor show , don't
know now.

george

[drujinin]

Moved my tri-axle trailer off the concrete and parked this mess on there to crawl around underneath. Not so sure that offering the use of my tractor was a good idea? This transmission case is broken on both sides where the 3 point attaches and already has been repaired once. Apparently this has power down on it and will lift the rear end off the ground which puts about 2 or 3 tons of pressure on all the joints! I am going to take the rear wheels off to look closer and see if its fixable or if i should tell him to look for a used transmission case. This is a Vladimir Diesel T25 tractor imported by Belarus in the late 1980's.

[usmcpop]

This is a Belarus and I doubt the Czech stuff would fit. Happened across this:

All States Ag Parts has salvaged a Belarus T25 Tractor for used Tractor parts. Call 877-530-4430 for parts availability and pricing.

[drujinin]

I'll forward the number and maybe get paid to do a changeover which would be less aggravation for me.

[drujinin]

I got time to start repairing. I put a piece of steel inside the hole, then Migged it in to stop the oil leak. Didn't appear to crack as it cooled, maybe cause I used short beads? Worst casting I've ever seen! Large porous, granules, not like fine grained casting, I'm used to seeing. A pipewelder guy at work is going to give me some Cast Iron repair rod that he used at a boiler plant before. He thinks it may minimize shrinkage while cooling. There is going to be a big hole that will need to be filled as a smaller chunk pulled out of the original broken piece. This spot is going to cause trouble. I'll grind it back to bevel the edges around that.
I have photo's that I will post as time allows.
drujinin

[vicegrip]

I would like to learn more about the make-up and processes
used today, as opposed to the 40's castings which when
broken up for scrap, take tremdous effort and reveal a fine
and consistant grain.

vg

[bruce0777]

I got time to start repairing. I put a piece of steel inside the hole, then Migged it in to stop the oil leak. Didn't appear to crack as it cooled, maybe cause I used short beads? Worst casting I've ever seen! Large porous, granules, not like fine grained casting, I'm used to seeing. A pipewelder guy at work is going to give me some Cast Iron repair rod that he used at a boiler plant before. He thinks it may minimize shrinkage while cooling. There is going to be a big hole that will need to be filled as a smaller chunk pulled out of the original broken piece. This spot is going to cause trouble. I'll grind it back to bevel the edges around that.
I have photo's that I will post as time allows.
drujinin

I welded a tractor motor one time that cracked all the way across almost all four cylinders. maybe 3 feet long. No one would touch the job and he brought it me. As you I grooved it out, preheated it as you. used cast iron stick rods, and the biggest and best secret is to weld maybe almost and inch at time and wait a long long time for it to cool maybe even five minutes to be extra safe.. Your cast iron sounds like the one i did Grainy sandy pot cast iron. It was an ugly scar of a weld that I did not grind to be stronger but it worked for years with no complains.

[drujinin]

I ground the patch clearances last night. Used the bolts and the mounting face for alignment. I put a jack under the piece to hold it up. Screwed in the bolts with the jack snug. Checked the wiggle on the bolts. Removed ground some more clearance. Re-installed, tightened jack up a little more. Bolts were very snug. (I'll thread chase the holes in the end). I have a sample of Forney's "Noma-Cast" (non-machineable repair rod). End of piece is an inch & quarter. Pre-heated, welded one bead on one end, peened, welded one bead on the other end same amount. Too dark to continue plus I want to keep it cool (not overheating the cast) while not hurrying.
I'm thinking that when I get around to the machined face and the final passes, I'll switch to "Chronatron 211" which is a machinable Nickel based rod. Its advertised as being "God's Gift to ALL Cast Iron Welding Men!" This way if it spills into the bolt holes I'll be able to still chase the threads.

[drujinin]

See attached photo's!
I was disappointed in the chronoweld 211, the noma-cast actually laid in better.
Critize the job if you want.
If it holds and don't leak, then everyone will be happy, no matter how ugly it is.
drujinin

[drujinin]

I used the noma-cast on all the root welds, trying to put the chronacast on to shape. It just didn't perform as expected! :(

[Hotfoot]

Good write-up....Now, if he has any sense... hit it with a spray bomb, clean it up and sell it in the spring!...and he'll either keep paying the Piper, or learn the limits of small machines. :)

[drujinin]

I adjusted the brake on the repaired side and put the wheel back on. Filled the transmission with gear oil, then started the engine and drove it out of the shop. Took it out for a little test drive to move the oil all around in the transmission. Parked it while I investigated the previous repair on the other side. It didn't take much to break through the repair on the other side. Apparently it was a "Cosmetic" repair verses a real repair! I pried the piece out without much effort. Now is re-do the other side for a REAL repair.
In the meantime monitoring the first repair for oil leakage. Apparently I got it sealed up becaause after 4 days, still no leakage! :D