'76 450SL Manifold w/cats Removal - Need Advice
 

My beautiful Spanish Lover Blue Belle ('76 450SL) seems to have something like a crack near the flange on the right side exhaust manifold. I changed the exhaust recently and it's not loose, but what kind of fun am I looking at to get the manifold off :mad: ? I can't see how I would possibly remove the lower bolts. I can't even see where they are.

Anyone ever heard of a crack around here before and know if it's weldable? My year has the cats in the manifolds :rolleyes:

Any words of wisdom before I jump in?

I did the Waterpump etc and the rest of the exhaust and about a 100 other things on her, but feel I need to fix this to sell it. It sounded so good before - then one day it developed this sound. I assumed a flange leak, but it isn't.

Thanks

RZ Rob

These manifolds are cast iron and can be welded using cast iron rods or stainless steel. Welding cast iron it a bit tricky. It requires a bit of pre-heating, stich welding, peening the weld as it cools, etc. Before you or your welder start be sure that you bolt the manifold to a FLAT steel workbench so that the flange that you are welding remains in line with the other flanges. Otherwise you will have a leak at least and another crack at worst.

Depending on the state in which you live you might be able to ditch the converters.

76 450 Sl Exhaust Manifold
 

You don't have to remove the lower studs on the exhaust manifold just loose the nuts on them up. The exhaust manifold is slotted on the bottom, simply remove the upper bolts and lossen the lower nuts and pull the manifold up and out.

With the manifold off it would be a nice time to replace the bolts and studs.

Good luck, not the worst job in the world, but it can be a pain.

Later
JOB