C-Body 440 rear main seal

My brother's '74 New Yorker Brougham has been parked in indoor storage for the last 15 years. The rear main seal is toasted, so bad that a lot of oil leaked out just sitting. I think with a new rear main and a little resurrection work it could run. The car is in decent cosmetic shape but I don't think a C-body sedan is worth much these days so it doesn't warrant a swap or rebuild.

The tires are all dry rotted but 235/75R15s are pretty easy to come by.

I've done the RMS on a Jeep 4.0 and a 318. Is the 440 going to have a split rear main? How much subframe or suspension is in the way of the pan? I have an engine hoist if necessary.

440 has a split rear main seal. The seal retainer is a cast piece, and has a seal on each side. They tend to leak there too. There are aftermarket billet aluminum ones that are much nicer than the original factory piece and seal much better. I've installed a few of them.

I can't remember how much room there is in the late C-body to drop the pan. Last one I did was in a '72 Road Runner with a Milodon pan. Took some wiggling but got the pan in and out without having to jack the motor. The only obstacle I can think of in the C-body would be the exhaust crossover/y-pipe.

Big block Chrysler is generally pretty easy to get the pan off, because its a whatchamacallit type block where the pan rail is down level with the heads of the main bolts. Steering linkage will probably be in the way, and if its single exhaust, the Y-pipe may interfere as well. Getting the seal out and back in depends upon whether its a rubber or rope seal. The rubber ones generally come out reasonably easily, and in is cake. The rope style requires a chinese finger trap style of puller to roll it into the upper slot, but its also possible to just pack more material in to repair the leak. Odds are its rubber. Read up on the instructions for the side seals on the seal retainer.

I would guess that the engine is original to the car so whatever is in there was installed by someone smoking a camel in 1973. I will look into the aluminum seal retainer.

Even though it's not worth putting money into an early smog motor I've heard these have relatively good heads but low compression. It has a single exhaust, do true duals (twice pipes as my dad says) do anything for this vintage of 440 or is it just for sound?

I learned to drive in a '76 C-body with a 400. The exhaust crossover is right there so you may have to drop the exhaust. I say this because the rear main on that car heaved to the point where it would smoke from under the hood when you pulled from a light because of the oil slopping out onto the crossover.

I also learned that you cannot kill a B engine from mere lack of oil. I drove it for two weeks with no oil and it kept soldiering on (as much as a wheezy lean-burn 400 can soldier, anyway). Defeated, I put four quarts in, resulting in the lifters shutting up and the rear mean slobbering all over the exhaust again.

Most of the lack of power is low compression, very conservative ignition timing, and really, really mild cams. The theory for clean emissions at that time was to burn very "cool" to reduce NOx and have wee little cams, often heavily retarded, in order to minimize unburnt gases at idle and low load. Any horsepower made was purely accidental.

A little more compression and even a mild RV cam really wake the engines up. Some of those old turds had 7.5:1 compression!

The dual exhaust will help it some. So if you need that as an excuse to cut the Y-pipe out, go for it.

It's a big luxury liner. Please don't put Flowmaster 40 series on it. Something like the large body Dynomax Super Turbo (used to be labeled Hemi Super Turbo) might be quiet enough.

If it's a Lean Burn system on there, reasonable power can be had going to a conventional electronic ignition and a non-Lean Burn Thermoquad. The Lean Burn Thermoquads can be modified, but swapping on a truck 'Quad would be easier.

Back when my brother was driving the car daily we did some work to it. The carburetor is a rebuilt Thermoquad, an open element air filter, new plugs and wires, cap, rotor, etc.. After all that we dialed the timing to factory settings with the timing light and had someone tune the mixture with an analyzer. It still didn't run right so I asked for recommendations at work and was given the number of an old school mechanic. This guy comes over with a cigarette hanging out of his mouth and starts yanking vacuum hoses like he's going through a spaghetti bowl. He then sets the timing by ear and by then we think he's nuts. He tells my brother to lay into it on the way out around the block. The old 440 lays down a patch like it's never done before! I think we paid that guy $40 cash for his help.

Your 400 rear main sounds exactly the same as this one. It's slinging oil like crazy wherever it goes. I'll check into the RV cam.