Cleaning up the undercarriage on a rare Continental SC

Collectors like to think of their prized Bentley motorcars as pampered pets that never go out in the rain.  We forget that the people who buy these cars new often don't see them that way.  To some, a Bentley is just a car.  This particular car is a Continental SC - the rarest and most valuable of the Continental variants Bentley made before the Volkswagen transition.

Beautiful as the car looked from above, a look underneath showed hard driving through several Chicago winters.  Lots of salt water damage down there.  If this was a more common model, the owner might have looked for a better one.  In the case of these SC models, 2019 auction prices were topping $250k and there are no cars for sale. And the owner liked the color, so the die was cast . . . we had to clean this up.

Here is what we started with:

Here it is now:

Everywhere we looked there were rusted, corroded parts.  Everything had to come apart for proper repair.  It seemed overwhelming, but we did unravel it slowly but surely.

We took the exhaust system off the car.  The front sections of these exhausts were bare stainless, with the catalysts painted black. The rear section was painted flat black.  On this car the front stainless was rusted and nasty, and the rear was peeling back paint.  We stripped the flaky black from the rear and had it coated in hi temp flat black, as it was originally.

We took the front sections off, used acid to take off the rust and then ground the heavy rust smooth on the catalyst

These are really heavy steel so they last a lifetime, and we brought the appearance back for the most part.  Here is that piece back on the car.  You will note the transmission pan is still spotted with rust.  That pan was made special for these Bentley cars and we could not find a new one so we fixed what we had

The transmission pan looks like a stock GM unit but its not.  Its deeper and has a side drain.  Most importantly, it is NLA.  We cleaned and refinished this one.

The engine oil pan was a bit more involved. The photo below shows the pan after we cleaned it off.  The front face had rusted deeply that oil was starting to seep through the rust.  We were able to find a good used pan to refinish.  But to get there, the rack had to come out (reseal and refinish) the crossmember had to come off (sand blast and refinish) and all the hardware had to be cleaned and plated or replaced.

This is what the hardware looked like, up close:


Elsewhere under the car the brakes were all pulled apart, rebuilt, and painted.  

Here they are now:

Many small parts were replaced, and the bigger pieces were either removed and cleaned up, or done in place. 



We didn't want to remove the subframe so the biggest parts were cleaned up and painted in place, using POR15 or Rustoleum.

The accumulators and valve bodies were all available, so we replaced them.  Valve bodies on the older cars are NLA and we have no choice but to rebuild. On these newer cars, when they rust like this, we change them:

Rusty springs, shocks, and bushes were all renewed:

Rusty hardware was cleaned and cadmium plated as original

We replaced all the pipes and hoses we could get

And now . . .

Rubber covers on the suspension joints were replaced

When you look from underneath it’s hard to see how much work went into this.  In the photo below you see an exhaust pipe whose rusty appearance somehow stood out for the owner (it is pretty visible from in front) We did improve it. The silver oil pan is actually the replacement described above. When that came out we cleaned the sump and repaired the oil level sender you can see on the left side of the pan. The steering rack was removed and fitted with new seals and paint.  The yellow paint marks the the bolts holding it in.

This was the left front wheel area, before and now.

As you can see, its not perfect but it's a lot better.  Getting it perfect would have involved stripping the undercarriage completely bare after removing the engine and rear suspension and everything else under the car.  Such a job would have run well into six figures and was not justified on this car.

We cleaned the original chrome on these wheels and fitted new tires which were shaved for roundness because they don’t center well on these custom wheels. 

When the car left the factory one of the last steps was for a quality control inspector to check critical nuts and bolts and paint them yellow to show he checked them.  Here is Bobby repeating that process on this car:

Here we are today:

The interior of this car is together already, as is the top of the engine bay.  Next step is to fix the rust holes where salty water ate through the roof and rocker panel metal, and paint those damaged areas.

On we go . . . .

© 2020 John Elder Robison

John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Land Rover, Bentley, Rolls-Royce, BMW/MINI, Mercedes, restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the car clubs, and he’s owned and restored many fine British and German motorcars.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

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