SL 450 Oil Pan Cracked

[nickjzee]

Gentleman,

A coworker of mine bought a 1976 450Sl (Sl450) and asked if I would come diagnose an oil leak.

I found a huge crack in the oil pan that was covered by an epoxy/resin/glue.

Is this (oil pan fractures) a common occurrence or did something strike it from the inside?

Thank you for your opinions.

[tecqboy]

I once saw a cracked oil pan from a dude using a floor jack to lift the car. He put the jack under the oil pan and lifted the full weight of the car on the oil pan.

[PanzerSD]

Originally Posted by tecqboy

I once saw a cracked oil pan from a dude using a floor jack to lift the car. He put the jack under the oil pan and lifted the full weight of the car on the oil pan.

that is probably what happened, someone in my cars past has mistaken the bottom tank of my radiator for a crossmember..

[rs899]

^^ could be. To replace an oil pan on a R107 is a big deal. Remove subframe or hoist engine.

[medieval]

I can't tell from the pictures, but is it pushed in, or out? I don't know how much a new pan costs, but it can be welded.

[Strife]

The shop manuals mention possible cracking at the rear that was alleviated by reinforcement ribs in the casting at the rear. I can't really tell from the pictures here but this looks to me like what happened. This is apparently a stress crack and there is probably no internal rotating part that hit it (if it did, you would DEFINITELY know).

It IS possible to support THE ENGINE/TRANS, ONLY, ALONE, by the oil pan safely, IF the weight is distributed over the entire base by a very thick wood block. I do this when replacing the subframe rubber mounts. I have a block made of stacked 1"x2"boards that were apparently glued or bonded together, sort of like a very thick butcher's block (a piece of plywood alone isn't going to distribute the weight).

I have an oil pan off of a 380SL M116 and it's a pretty impressive and thick casting, but not invulnerable. Unless you can find a truly expert aluminum welder (which is rare) who works at reasonable prices (even rarer), I would not recommend it. There is absolutely no way I would ever trust what you describe being done here without driving with one eye on the oil gauge at all times (which is basically impossible). If you think taking care of this is expensive, runnning out of oil would be REALLY expensive.

If you are looking for a JY replacement, it's true, there's no way around it, you have to lift out the engine or drop the subframe. And you can't use just any oil pan, it has to be from a W107 (one piece), not the two-piece from a W126, because of differences between the frames. Also, there MAY be differences between an "iron" M117 (a 350/450) and an aluminum M117 (a 500/560).

[nickjzee]

From what I deduce one side of the crack protrudes out and the other holds the same radius as the rest of the pan. It is hard to tell.