Gearbox Crack Repair

[palomar]

So this weekend I tackled the my gearbox crack with the quick and dirty JB Weld repair and so far so good. Hopefully the JB Weld will hold up to the heat, strain and vibration caused by regular use. Here are the pics, they were all taken with my iPhone so they are not the best quality.

The crack was above the hydraulic strainer. I started by pressure washing the tractor, draining the hydraulic fluid, removing the tire, brake linkage, diff lock linkage, fuel line, and foot rest. I left the two hydraulic lines in place and worked around them, although they were in the way a little bit.

Here are the materials I used: Brakleen, Dremel tool with small brushes I got from Tractor Supply, Car-go Metal Tank Repair Kit, and JB Weld quick Steele.

To prepare the area I started by spraying it with Brakleen. This stuff is very powerful, it removes everything including paint. I followed up with my dremel tool with the wire brushes. This removed all the left over paint and exposed the bare metal and the crack.


Here is a picture of the crack:

close-ups:

I think the crack was caused by over tightening of the hydraulic strainer.

Next I used some sandpaper to scour the exposed metal and crack. Then sprayed it with Brakleen one final time and let it dry completely. I then mixed and applied the Car-Go Tank Repair putty, followed by the JB Weld. I found the JB Weld to be easier to mix and apply, and in retrospect I would have used it exclusively. I filled the entire area. This may be overkill, but I decided it would better for functionality and look.

I let the putty cure overnight and then sanded it down a little bit:

I then re-filled the gearcase with hydraulic fluid and checked for leaks.

So far so good, and if it stays that way I will prime and paint it.

 

[rbargeron]

I'm wondering if the crack may have been caused by water freezing in the transmission. I don't think over tightening the strainer could put that much outward force on the wall of the gearbox. But ice might - like if there was rain water in there - maybe enough to be a couple inches deep? Of course its a bogus theory if you are located in Florida....

 

[radioman]

nice job! wouldnt it be better to grind out the cracks and weld it ? Right now theres is no point since you alreaday usedd brakeclean. welding and brake clear is a BAD combination.

Hopefully the putty stuff will out out for a long time, but I think it might last either a week or couple years. If it lasts more then a week, you probably will get to have it last a couple years, I would think, just based on my past experience.

 

[TripleR]

Good job, I have been surprised with how successful my repairs have been with JB Weld, but I haven't tried anything like that.

 

[palomar]

rbargeron,
You may be right, I am in Florida, but I just bought the tractor two weeks ago from somebody who I think bought it at an auction, so who knows where it has been. I thought that an over-tightened strainer over a long period of time and use might cause a stress fracture.

Radioman
No doubt, welding would be the way to go, but I decided to try the cheapest easiest, for me, method first. What's the deal with Brakleen and welding, can you elaborate, I thought it left no residue?

TripleR
I posted this on the orangetractortalks forum also and some people responded with JB Weld repairs that are 25 years old and still hoding. We'll see though, time will tell.

 

[dodge man]

Apparently if you weld after using it you get a very toxic gas. It is apparenlty a very serious thing.

 

[bitseeker]

So this weekend I tackled the my gearbox crack with the quick and dirty JB Weld repair and so far so good. . . .

There is one other step that would help stop the crack propogating. You would need to find the very ends of the crack (there are materials that highlight cracks) and drill a small hole at each end. This seems counter-intuitive, yet these holes would spread the forces over a larger area and reduce the chance of further crack extension.

 

[dex3361]

Is the case metal cast iron or aluminum? I cant tell in the images it looks like aluminum. Good looking job on the repair.

 

[shownuff]

I never had any luck with jb weld or any of those quik weld fixes but it looks like you put enough on to stop the leak

 

[k0ua]

I repaired a riding lawn mower transaxle once with JB weld. I went looking for the chunk of aluminum that fell out by following the oil trail backwards. (there was a broken partial tooth that got caught in one of the gears and pushed out the chunk on aluminum). I found it and cleaned the edges of the hole with gun scrubber, then JB welded the aluminum chunk back in, and covered the whole thing with JB weld, It lasted for years until I gave the old mower away. Still solid, no leaks.
James K0UA

 

[Deano]

I repaired a 10" crack in my stepsons jeep that lasted for two years till I bought one off of Ebay and rebuilt it. A year later he wrecked the jeep and he put the "repaired" one back in it and it is still on the road!!

Looks good! Hope you have teh same luck i did!!:thumbsup:

 

[rdsaustintx]

The engineer side of me wants to say you might have relieved the ends of the crack as long as you had a Dremel out.

The redneck side of me remembers a nailgun I dropped with a crack about that size. Lost one night waiting for JB Weld to dry. That was 6+ years ago and it still holds 100 psi.

 

[crazyal]

If it doesn't hold I would try again. Like others have said try and find the ends of the crack and drill them. To do this you can't just look at where the crack stops and think that's where it ends. I would also rough the surface up, say sand blast it to give the epoxy something more to stick to. You could also drill a few small holes in the cooling fins and run wire between them that would also help give the epoxy bite.

While welding would be best it would require you to tear down the gearbox, grind the crack out,and heat the metal before welding it to make sure you only had to do it once.

 

[gauthier]

If he was welding it,just grind the crack out,,but using jb weld or brazing,yeah,a drilled hole would stop crack,if,,you could find the ends of it that is,if you can't find the ends,you just drilled holes,,like said,they have stuff called dye penatrant to show you where crack is,,that area cracked for a reason and generally cracks grow,but in the meantime,you fixed it.

 

[palomar]

dex3361
The case is iron.

I did roughen all surfaces the JB Weld would come in contact with, using 180 grit, but I didn't take pictures. I wish I had thought of drilling the ends of the crack to ensure it does not spread.

Thanks for all the replies and advice.