Removing the Oil Pump on a 1936 Oldsmobile

Yesterday, visited my friend Pete (from whom I bought the Alfa). Pete’s a family friend, and an all-around great guy. He had invited me out to give him some assistance with working on one (or more) of his cars.

A few weeks ago, Pete told me he could use my help with his ’79 Volvo 265, which was exhibiting an intermittent no-crank symptom. He had checked two of the more obvious things: battery health and battery terminal condition. I asked him if he had thoroughly checked the battery ground cable, as I had experienced instances with that cable hiding extensive corrosion under its sheathing.

When I arrived yesterday, he proudly told me that several days ago, he had removed the negative cable, found extensive corrosion at the engine block, cleaned all that up, and has not had a lick of a problem since. So on to the Olds….

One of his prized possessions is his ’36 Oldsmobile L-36 convertible. Here is some background, provided by my copy of The Encyclopedia of American Cars, by the Auto Editors of Consumer Guide:

In 1936, there were two series of Oldsmobiles: the 6-cylinder F-36, riding a 115 inch wheelbase, and the L-36, with an inline-8 on a 121 inch wheelbase. The I-8 displaced 240 cubic inches, and put out 100 horsepower. Pete’s convertible coupe was the most expensive Olds in ’36, at $935. (The base Olds business coupe was $665.) Production numbers for the convertible totaled 931 (compare that to their volume leader 6-cylinder 4-door touring sedan, of which 66,714 were built). Survival rate of the convertibles is unknown, but certainly, Pete’s drop-top is one rare car.


A shot taken a few years ago of the ’36 Olds


Topside of engine. Restoration was done in ’90s, still looks great

When I visited last year, Pete was very concerned about the Olds exhibiting low oil pressure at idle. Yesterday, he reiterated those concerns, informing me that the most recent readings he’s seen showed 20-25 psi at cold start up with high idle, then descending to figures below 10 psi at warm idle. (These numbers are from a quality aftermarket oil pressure gauge screwed directly into a passage in the block.) There was straight-30 weight in the crankcase.

Pete had been conversing online with a self-designated pre-war Olds expert, who opined that the straight-8’s oil pan was NOT coming off until one first dropped the steering linkages. Pete wanted to try it without disconnecting the tie rods. I said that the worst that happens is, we bolt the pan back up and attack the linkages.

The oil was already drained, and drop light, creeper, and tools were waiting for me to get under the car and get to work.

There must have been 30 bolts along the perimeter of the pan. None of them were very tight, and most could be accessed with a ratchet and socket on a short extension. But six at the front were under the steering linkage, and required a box-end wrench, turning each about 1/6 of a turn at a time. It wasn’t difficult, just time-consuming.

I left one bolt in the front and one in the rear, both finger-tight, to prevent the oil pan from crashing down onto my chest. With a putty knife and a hammer, I gently tapped at the two back corners of the pan. At this point, my fight was with the copious amount of orange Permatex all along the edge.

A few taps later, the pan was free of the crankcase. By now, Pete was on the ground under the car with me. We removed the final two bolts. The pan wouldn’t drop further. At the front, the steering linkage was in the way, which we knew. At the rear, the clutch housing stopped us from sliding the pan rearward. We also had to get the pan low enough to clear the oil pump.

Pete suggested rotating it 90 degrees toward the passenger side. With two sets of hands on the pan, we did that. Success! In a matter of moments, the pan was on the garage floor.

The pan is where we want it: on the floor

The oil pump, now out in the open, was held in place by 2 nuts, needing only a 9/16” wrench to remove. The concern here was the possibility of loosening the studs onto which the nuts threaded. But as soon as I broke each nut free, I could see that studs remained stationary. The oil pump was in my hands.

Inline-8 Olds oil pump. Pump is driven by shaft (right) which extends up to camshaft

We both agreed that things looked very clean in there. There was the slightest bit of sludge on the pump’s pick-up screen, but it didn’t make us concerned. Pete’s next challenge is to find a reputable shop to check the pump, and if needed, rebuild it. However, after months of wondering what to do, he was both relieved and thrilled to have the oil pump out, ready to move onto the next steps.

Straight-8 crankshaft. Oil pump mounting boss at lower left. Permatex is not from 1936.

As a parting gift (!), Pete asked me to help him clean out his garage by giving me this front bucket seat from one of his Fiats. Does anyone need a black vinyl seat for a Fiat 124 sedan or wagon?


For sale: one Fiat seat


All photographs copyright © 2017 Richard A. Reina. Photos may not be copied or reproduced without express written permission.