Here's what happens when you overtorque drain plugs...

I sealed a crack in an aluminum engine block on a air cooled lawn mower, that threw a rod and it never leaked a drop of oil after the fix, I know its not the best option for a fix, you have to clean the surface before applying the JB!

 

Will a TIG weld generate enough heat that would damage the transmission?

 

I guess the only thing worrying me about welding it is the heat destroying the gaskets and seals.

I sourced a used r150f tranny with 113,000 on it for $700, $500 to install. Seriously thinking about just replacing it so I won't be looking under the truck everytime I fill up with petrol. What are some things to keep my eye on when checking out the used tranny? And what else should I have done if I do end up pulling the tran? Clutch, rear main, etc?

 

If you weld it I would disconnect the battery cables.

 

Use some heat absorbing putty to stop the heat transfer to the rest of the transmission.

 

I went through the same thing. Be careful buying used transmissions. Also you should pay no more than $300 for install.

 

The only problem with timeserts, or welding and having to drill and tap, is the metal shavings that get pushed into the trans and then become free floating in the gear oil, and that is bad. I had to do it on a 1971 VW engine that the cylinder head studs which are steel, are threaded into an aluminum magnesium aloy case(or block) and those 2 metals heat up and expand at different rates and eventually the studs will pull out destroying the theads. I did the drill and tap method putting timeserts into the case, long story short metal shavings got in, no bueno for me. Back to your situation, it's not like there is a pressure build up in the trans, there is a breather that , well breathes, so no pressure to worry about, I have and oxy acytelene set up and from what I have read braising is not an option on aluminum, I could be wrong so feel free to correct me. I would go the route of a JB weld type 2 part epoxy that can be tapped, that way if some of the debris does get into the trans it "shouldn't be too bad on it" but I would fill and drain it to wash the junk out.If I were you a good tig welder be my second choice. Good luck

 

I would say no, if the welder just tacks and lets it cool, remember it's just a case that holds the gears, tig is more "accurate" . Not too much heat absorbtion into the trans case.

 

Yea either some wet rags or what he said some Cool-Gel spray gel or some type of putty. Its not structural so the welder should'nt have to fill it in there deep just put a small and quick bead along the outside of it. Like a few people said put a hefty amount of anti-seize and go talk to a welder, it should'nt leak too bad you might be able to drive and talk to one.

 

Metal parts? psh, its soft aluminum

 

My brother builds hot rods for a living. I sent him a link to this thread, this was his reply. Bad, bad, bad. The ONLY way to fix it is to cut out the cracked area replace it with a piece of aluminum stock and tig weld it. Has to be PERFECTLY clean to weld so that means it will have to be removed. Is it a pipe threaded hole? He may be able to lightly tighten the plug, clean the area over and over with alcohol and seal the whole thing from the outside with a NEAT layer of Ultra Black or Right Stuff.

 

Im fairly sure it's not pipe threaded.
I believe you could fill the entire thing with aluminum then re-drill and tap the hole (I'd just make it a small hole and run a fine thread bolt in it). Aluminum shavings won't hurt much in a manual trans and dumping a few quarts of cheap gear oil through should flush most of it out.

 

Well she's sitting down at the welders right now. Got under there yesterday with brake cleaner, acetone and rags and cleaned the wound up pretty well. You can see the two hairline cracks that run up and down off of the main crack.

A plug still fits in there, and I was very close to just JB'ing it up yesterday. At this point I have no reservations about sealing up the plug permanently. When I move to California I will be very near Fresno, and will end up buying a rebuilt r150f from MC eventually, so in the meantime I need to get this taken care of so I can prepare for the upcoming move in three weeks. And I have to fly back East for a week before we leave, so that gives me 8 days to get this done. So now I'm just waiting for the welder to do his thing.

 

So you use some thread compound or some loctite. Even some RTV if need be.

 

HOLY BALLS

Torque wrench on a drain plug....

 

Yeah yeah its a flippin hoot; a real kneeslapper. Thank you

 

I couldn't imagine a welder creating that much heat as long as you don't do the whole crack at one time.