Cracked 3.8 e-type sump

I’ve had this e sump on the shelf for 20 years, and upon finally getting around to cleaning it up for use, I find that it has several cracks related to a shallow dent. I consulted a young friend, a talented welder, who asked what the alloy is. Does anyone know, or perhaps more directly, has anyone been successful in welding one of these pans? Any other form of repair I should consider?

The secret is to get it as oil free as possible: I would soak the bad spot in acetone, dry, repeat, then let it sun dry.

Not sure of the alloy.

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If you search “welding aluminum sump” you’ll get many many hits recounting the success others have had in welding or having their sumps welded where cracked. No mention of the the particular alloy I coulde see in a quick scan but lots of discussion of successful welding.

Probably a 3xxx series alloy though. This might be helpful.

Paul’s correct in that preparation is super important.

It might be DTD424; that’s what the cylinder heads are.
TIG weld, Argon shield gas.
I would take a cutting wheel on a die grinder and make the crack into a weld prep, like a valley about half the depth of the thickness, so the welder will be filling up the valley with filler rod.
Short passes an inch or two and let it cool down in air between passes.

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Excellent. Thanks for the input.

I second the cleanliness importance. I have a 3.8 sump on my 120 that had a welded crack. I had a chemical plant pipefitter do the welding. That particular plant had miles of aluminum process piping and dozens of aluminum storage tanks, so they were particularly expert at welding the stuff. I might suggest that you check for cracks using a penetrant dye test kit. Not expensive and easy to use, it will reveal cracks you can’t see otherwise. When you find them all, drill a hole at the very end of each crack to keep it from spreading under the thermal stress of the welding process.

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Thanks, Mike and others. I’ll share this thread with the welder. If he doesn’t already have the penetrant dye, I’ll get some. I’m glad to know that it is at least potentially repairable - wasn’t looking forward to the prospect of having to find one.

I’d start by putting the sump on a barbecue? You will be amazed how much oil oozes out!

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Greetings All,

First thing, degrease it.

Personally, I would take it somewhere that uses a heated vapor bath of Methylene Chloride.

I weld. Biggest issue is that people believe an aluminum casting that holds oil can’t possibly absorb oil…you would be wrong.

Check with Ford.

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Yep: most alloy sumps are essentially sponges.

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Absolutely. And you can add bellhousings to that list, along with anything in coolant loop. I had them weld up a badly corroded XK120 thermostat housing. Even after a solvent soak and a thorough bead blast, the thing wept green antifreeze when he hit it with a TIG arc.

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With smaller parts–sump-sized and down–I’d boil then in an alkaline soap solution. I used a half barrel, over a frame Id made, fired with wood.

Then, soak the part or area with acetone, then sun-dry them. Would get rid of most oil and coolant.

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Greetings All,

Back when Ford decided to do their thinwall transmission castings, they wept.

Loctite was called in. Ford then used a autoclave style bake system coupled with Loctite. It works great.

I do wonder what happens when that casting is hot tanked in the future. Someone is in for a surprise.

The welds won’t weep. I’ve built many vacuum tight welded aluminum devices.

I had a welder place a 3/16th plate on the sump. he said it went on very well and the alloy was good quality.
Did a leak test with gasoline . Does not leak after 12mths driving.

True: properly welded, it shouldn’t leak.

Lovely - bottom line is that it is quite doable. Thanks again all.

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