pyropete125

Anybody ever see this? The car drove perfectly. No leaks or anything.

Oddjob

So it's not cracked thru the casing, not leaking fluid? It's the surface delaminating and flaking? The top pic looks concerning. The others do look maybe more superficial?

I've seen some surface imperfections in various factory castings, oil pans, etc. But nothing that noticeable before.

pyropete125

No leaks. No funny noises. Yes the top one is the worst. Yes it looks like the casting is delaminating and flaking.

Voith

Sandblast that off, it looks like it was overcoated with another layer of aluminum for some reason.

jeyjey

"Delaminating" would suggest it's laminated (like wrought iron). But it's cast, so these imperfections must have been from the original casting process. If it's lasted this long, I can't see that changing. Just wire-brush them off.

gruhsy

Cast Aluminum sometimes corrodes is layers or sheets.
I have seen this before at work. The systems I work on are installed on ships for a 7 year cycle.
I see tons of different cast Aluminum all the time.
Clean it up and just keep an eye on it.
Ships see far harsher conditions than the transaxle

Millermatic

It’s been 20+ years... but I used to work in a small industrial (vs. art) foundry that specialized in sand-casting bronze and aluminum. Lots of machine parts. Admittedly... I didn’t spend a lot of time with used 30-year-old parts and I worked more with bronze and “marine brass”... but I’ve never seen damage that widespread that looks like that and in places like that from the casting process. I can’t believe that left the factory that way. Cracks usually happen from poorly controlled cooling - in a mold, a thin part of a cast will solidify faster than a thick part. If they are adjacent... there’s a risk of cracking. Mold-makers can embed metal heat-sinks in the mold to help keep heat in areas of concern. If I saw something like that in the foundry... I’d melt it back down.

From my experience, most aluminum failures give rough breaks. I’d maybe expect “flakes” in thin areas where metal didn’t flow well.

My completely wild-guess theory relying on knowledge from a job from another life time? I’m wondering if the case didn’t suffer from an impact from running over something when it was really hot...

I suppose some of those could be due to aluminum flowing under a broken part of a mold if a “wet sand” process was used. But that seems a stretch and doesn’t apply to some of those images.

I love metal work... I’d be fascinated to know how that happened. Know anyone with an industrial CT scanner or x-ray?

Mike Goebel

Hit it with a putty knife and see what happens.

Mike G.

pyropete125

The big flake I broke off and still no leaks.

Super strange for sure.