W126 Front Suspension to Body Rusted. Repairable?

[777funk]

The points where the front upper control arm mount to the body seem to be rusted pretty bad. Has anyone fixed such a problem?

Is there a good way to know how much rust is still ok to drive?

[Diesel911]

Pictures?

Without pictures all I can say is that the 2 original bolt holes need to be retained in their original positions and alinement. Whatever welding is done needs to preserve that alinement.

[jake12tech]

A competent welder can fix it.

[777funk]

Heres one picture of the rusty mount.

[BillGrissom]

The photo definitely isn't where the upper control arm attaches, which is above the middle of the wheel. Those bolts are inside the engine bay. You appear to show near where the steering idler arm housing attaches. It is like a cylinder on a rod. The rust on the body above looks like from battery acid. Hard to tell how bad it is until you attack it. Could just be surface rust which will brush off with a wire-brush on a drill or might be able to easily push a screw-driver thru. Regardless, looks fixable. If you can't weld new sheet-metal to cover a rust-thru hole, you could use fiberglass then Bondo, if just an area of thin sheet-metal. Structural steel rarely rusts thru since so thick. Step one is to remove the tire. I put a Battery Mat under my batteries to absorb any acid vents. A sealed AGM battery doesn't leak.

[Diesel911]

The part in the picture does look like it could be repaired with welding. However, there could be more extensive rust under the coating.

[Diesel911]

Originally Posted by BillGrissom

The photo definitely isn't where the upper control arm attaches, which is above the middle of the wheel. Those bolts are inside the engine bay. You appear to show near where the steering idler arm housing attaches. It is like a cylinder on a rod. The rust on the body above looks like from battery acid. Hard to tell how bad it is until you attack it. Could just be surface rust which will brush off with a wire-brush on a drill or might be able to easily push a screw-driver thru. Regardless, looks fixable. If you can't weld new sheet-metal to cover a rust-thru hole, you could use fiberglass then Bondo, if just an area of thin sheet-metal. Structural steel rarely rusts thru since so thick. Step one is to remove the tire. I put a Battery Mat under my batteries to absorb any acid vents. A sealed AGM battery doesn't leak.

Take a look at the attached picture. The OP's pic is showing part of what is part of the part the guide rod goes into. There are 2 ends to it rubber isolated and with 2 bolts holding it on. So, it is well supported.

[pawoSD]

That photo looks like one of the cars we bought as a parts car long ago, the undercoating can hide a LOT of rust...try poking around with a screwdriver to see how much is solid...what looks solid might be rust held together by undercoating. By first glance it doesn't look good...

[BillGrissom]

Originally Posted by Diesel911

Take a look at the attached picture. The OP's pic is showing part of what is part of the part the guide rod goes into.

Forgot a W126 is quite different from my W123. I wondered what that bulge was.

[Diesel911]

Originally Posted by BillGrissom

Forgot a W126 is quite different from my W123. I wondered what that bulge was.

I only recognized the picture because few days before I was looking for something else and came across a video about changing what is called the guide rod on a W123 but the vid was on the W126. I watched the vid, and the guy also changed the rubber bushings on the part that goes into that bulge.

[compu_85]

To be honest, if there's that much rust on the subframe mount, and in the *middle* of the structure above it... it's time to give up on that body.

You'll spend many thousands to have it fixed properly, and then find other rusty spots that have to be addressed. If it's that bad in that location, it'll be that bad elsewhere. Trust me, I know from experience on my SDL

-J