Seeing some of the projects that folks in the ACMOC community are working on leaves me impressed, a bit envious (esp. of some of the shops!), and just a bit under-qualified to be attempting my restoration work on the old girl. But being under-qualified has seldom kept me from trying stuff...

Which brings me to today's question. Hanna came to me with a crack in the differential that had been welded, as you can see from the attache pics. (You also see my sophisticated, top-of-the line 'shop'!).

The problem is that the crack still leaks gear oil. Over the winter it would lose about a pint a week (into a bucket I stuck under the crack).

Given my less than expert welding capabilities, I anticipate speaking with the folks at Mobile Maintenance, a local outfit that services heavy equipment, including sophisticated welding. I will be speaking with them on Monday or Tuesday, but wonder if there is wisdom in the ACMOC community about this. Perhaps questions that I should put to Mobile Maintenance? (Of course the ideal would be to replace the differential housing. But that is well beyond my budget...)

As always, grateful for the wisdom of this community.Seeing some of the projects that folks in the ACMOC community are working on leaves me impressed, a bit envious (esp. of some of the shops!), and just a bit under-qualified to be attempting my restoration work on the old girl. But being under-qualified has seldom kept me from trying stuff...

Which brings me to today's question. Hanna came to me with a crack in the differential that had been welded, as you can see from the attache pics. (You also see my sophisticated, top-of-the line 'shop'!).

The problem is that the crack still leaks gear oil. Over the winter it would lose about a pint a week (into a bucket I stuck under the crack).

Given my less than expert welding capabilities, I anticipate speaking with the folks at Mobile Maintenance, a local outfit that services heavy equipment, including sophisticated welding. I will be speaking with them on Monday or Tuesday, but wonder if there is wisdom in the ACMOC community about this. Perhaps questions that I should put to Mobile Maintenance? (Of course the ideal would be to replace the differential housing. But that is well beyond my budget...)

As always, grateful for the wisdom of this community.

  

I repaired a crack in the water jacket of an old diesel engine with a product called locknstich. Basically it is a non welding process where holes are drilled and tapped and a screw is threaded into the hole and broke off. Each hole interlocks with the previous screw creating a seal for the length of the crack tying it into solid material at each end of the crack. Look on the internet and watch some of the videos of people using the product. It is something a guy with a drill and a tap can do without the hassle of attempting to weld cast iron. it sells as a kit which includes everything you need to make the repair. In a no stress location I think it is easier than trying to weld or braze a crack. bboaz

Hi, Onfoot.
What would make that particular weld repair more difficult is the oil which is undoubtedly in the crack itself - which may well be at least part of the reason the earlier weld still leaks.

I personally would make the attempt to weld repair it but I am also not quite a novice welder. That is not to say that I would be successful but, given past experiences and successes, I would try.

How-wevver, if you are not pretty confident in your own ability, I would suggest leaving it to the 'ex-spurts' - an 'ex' is either a has been or an unknown quantity and a 'spurt' izza drip under pressure.

I have never used the 'lock-n-stitch' method that bboaz mentioned by I have heard good reports about it.

www.locknstitch.com/index.html

Just my 0.02.

when dad worked for bonel bros they had the agency for belerus tractors which had one slight problem you couldnt keep oil in the sump due to porous castings so the fix was to pull the sump off and clean it thoroughly and coat it with red lead paint once cured they would refit with a new gasket and problem solvered. may be that is the solution for you.

another method would be to clean thouroghly and flow solder over the area inside that would seal the casting.

cast is hard to arc weld especially old cast as it is unknown composition and the rod used depends highly on the type of cast iron or cast steel. that's why bronze welding with a oxy set is better for this kind of work its lower temp and doesnt shrink the same plus less localised heating as its slower the heat spreads more.

a tip no matter what you choose is pre heat the whole housing before welding and the best way to do that at home is to build a fire it a pit in the ground, let it go to coals and place the bare housing in it burying it in the coals add fresh timber or coals to keep the fire going slowly. if you have access to a wrap around induction heater well you could use that not many shops would have one though. after welding bury it in the hot coals again to slow the cooling. its why blacksmiths shops had dirt or sand floors so they could bury things in the floor to control the cooling and dirt wont burn.

heating will also help remove the oil residue.

If that so so weld is working (not cracked and holding the parts together and has been for some time) why risk creating a problem. Solder or JB weld to stop the pinhole leak. Use a blow nozzle with a rubber tip on the underside and leak detector on inside and pass the nozzle around till you find the exact part (is the gasket sealed).

Quickly then I've got to go...
Lots of good advice but don't use JB weld internally ....bad ju juj ... the oil in the weld will prevent it from being welded again ... baking it or heating MAY remove the oil but all good plans have a bubba (you know Bubba Murphy). to me all the above sounds like doable fixes but your looking to do it and you know your limits My advice would heat/bake thoroughly let cool grind to shiny metal and clean with ether or isopropyl alcohol ...."NOT JB" but I use a steel enforcement putty $7.99+sh for a tube at 'Taryl Fixes All dot com' and don't let Taryl fool ya he's smart like a fox. The "Taryl Putty" made by Valco is a two part putty.... is really good stuff heat and oil resistant . put it on, can smooth it out by pointing it with wet fingers or a small damp spoon let cure be sure to mix well and don't make tiny batches
Good luck

I think Dan's is the better way unless you want to get the housing off the machine so you can burry it like Train suggests. Since it looks like the crack stopped after the first weld just leave it alone. I don't know the best cleaner to use, but have had success on fuel tanks with JB weld. There are several products other than JB weld, but don't know how you know which is best. Had a machinist recommend Devcon 2 part epoxy, it lasted on a water jacket. Now that I count that was over 20 years ago, so could be many improvement in the epoxy glue world in that time.

devcon makes a range of epoxy products and i have used their metal filled epoxy before it works well.

loctite (permatex) also had a putty that was specifically for patching metal fuel tanks and radiators. contact thier tech advice service they can recconmend a product in thier range

You guys are great! Almost as good as the internet!
I'm continuing to check things out. At the moment, I am most impressed by Bellzona 1161. You can check it out here: www.belzonabritishcolumbia.com/en/products/1000/1161.aspx#. But I will let you know how things turn out, for sure. And I continue to check out all the suggetions.

Leave the existing weld alone and try the threaded plug (locknstitch) plugging where you can see definate leakage.