The Stovebolt Site Forums The Shop Area Engine Shop Oil Pan Question

Good afternoon.
I have a '55-'57 model 261 in my '53 1/2 ton, rebuilt last year, and ever since has had a pretty decent oil leak. This weekend, in an attempt to locate the leak, I cleaned the entire underside of the engine with simple green. While doing so, I noticed a very small pin-point size black dot that would re-appear when I would wipe over the area; about 2" from the oil pan drain plug. So I let it sit and after about 2 minutes, it accumulated enough oil to form a drip, and dropped. It's seeping through the pan!

So, my short term solution is to drain the oil, scuff the paint off that spot, and spread JB Weld, and re-paint after a day or two. I think, given that this pan is obviously corroded, I need to find a good replacement. (hopefully this provides a fix, and my fears of a rear main seal leak were inaccurate)

Question: Are all oil pans on 216/235/261 engines the same? If no, how do I know which one I have/need?

I'm not recommending this at all, but old ranchers would drill a hole there and put in a sheet metal screw with rubber gasket. That's not something you'll want to do, though.

Once you drain the oil you can scuff up the area were the pin hole is and see how bad it is ,I would think if corroded it would be on the outside .It may be able to be welded?

They are not all the same. The pans for passenger cars and trucks are different and some trucks also had a different design. I'll attach an image of a couple I have. I ended up using the 1956 pan on the 1959 235 because it fit the 1952 truck chassis better. In your case, I think your short term solution should work fine, but as somebody said, you can put a screw in there, too. It might help keep oil from seeping out so you could epoxy better. Just get the pan as clean as you possibly can. I've seen JB Weld fall off oil pans, auto transmission pans, etc that were repaired this way before. Good luck!

Forget the JB weld- - - -use a product called "Marine-Tex". It's much better than JB where adhesion and leak sealing is concerned. Also, since rust holes are cone-shaped, you're seeing the tip of the iceberg. The hole on the inside is much larger than the pinhole that's visible. I'd suggest drilling a 1/8" or possibly a 3/16" hole where the leak is, and putting a pop rivet in the hole before applying sealer. Scuff up a radius of at least 2" around the rivet down to bare metal with coarse sandpaper- - - -80 grit or maybe even 40 grit, to give the metal some "tooth" for the sealer to grab. Drain the oil and jack up one side of the truck while you're cleaning and patching so you won't contaminate the repaired area with fresh oil while you're working on it.
Good Luck!
Jerry

Another thing. My pan has epoxy of some sort in a couple places. There is epoxy on the outside and inside in each place. I think doing it that way and the epoxy meeting in the middle helps to hold it in place. It can't simply flake off. Also, cleaning first to remove all oil would be important.

Yes i plan to scuff the paint off down to bare metal and clean very well with gasoline or carb cleaner. I'm hesitant to use anything on the inside of the oil pan, in the event a piece doesn't adhere well and flakes off. Same reason I really don't want to run a sheet metal screw with rubber washer up into the oil pan, in case a metal shaving gets into the oil.

Does anyone produce a reproduction oil pan?

There used to be reproduction pans, but the problem was (as I mentioned) they didn't fit every vehicle and there wasn't a great demand. I haven't seen one for quite a while, however there could be some old stock kicking around, I suppose. I don't know if you've looked on eBay lately, but a used oil pan is going to sell for more than you can purchase an entire decent 235.

Let me pass on what I did with a gas tank for a log splitter we own in NM. The gas tank had held water before we got it and it had rusted badly...several (over 30) pin holes and some of those were about 1/8 inch or more. And the metal on the bottom part seemed thinner as a result of the rust. A new tank for the motor was $125 plus shipping, and the seller was careful to point out it wasn't an exact fit but he thought it would work with some modification. So I split the old tank at the mid-joint, cleaned it within an inch of its life, mixed JB Weld (regular, not the Kwik-Weld variety) and thinned it with acetone. The JB Weld people told me I could also use lacquer thinner, but I didn't have any handy that day. They told me to use no more than 1 teaspoon to 2 tubes of the JB Weld, but I didn't follow that advice. I added maybe twice that much, mixed it very well and then painted on a thick but uniform coat with a short hoghair brush. I did this on the top and bottom and over the lip of each part where it had been split. I let that dry/cure for a few days and then I epoxied the two halves of the tank back together and let that cure. Never have had a problem and that was over 3 years ago.

However, I think if I had to repair an oil pan, the best way would be to drain and remove it, clean it like crazy, inspect well and find all holes and use my oxy-acetylene torch to braze every one of them very nicely. You could also use silver bearing solder (buy the Harris StayBrite and be sure to get the flux with it...they sell a small pack in a plastic tube: https://www.harrisproductsgroup.com...ng/Lead-Free-Solders/Stay-Brite-Kit.aspx ) and a common MAPP torch. Either of those fixes isn't hard to do and will last about a week past forever if you do them right.

Gasoline is a poor choice for leaving a clean surface. Gasoline is a complex mixture of low to high boiling hydrocarbons, the highest having boiling points of over 400 deg F. These higher boiling components are low in concentration but will leave a very slight oily residue. Acetone would be a much better choice. Lacquer thinner should be OK also.

The best solvent that I use for cleaning off oil, fir pitch out of clothing, etc. is BBQ lighter fluid outdoors in a well-ventilated space. It doesn't much affect car paint, most plastic, clothing dyes, etc (test it first).

Old acetone can have reacted with itself (shame on you, acetone!) to produce a condensation product that is less volatile and might be a bit oily.

I use diesel fuel for crude cleaning but BBQ lighter fluid for the wipe off. A couple hours ago, I used it on the outside of my oil pan before painting. That was after Gunk degreaser.

There's a simple way to enlarge a hole in the oil pan to make it big enough to insert a rivet without drilling- - - - -use an ice pick, an awl, or a tapered punch. No shavings, and no danger of bearing damage. Pop a steel river into the hole, clean up and sand the outside, and lay on a layer of sealer.
Jerry

Don't know if it still is, but that stuff used to be simple naphtha in a special can with a higher price tag.

Methanol (wood alcohol) is one of the best solvents to use when you want a residue-free cleaner. There's been a lot of hype about how toxic it is when used as hand sanitizer, but generations of wood workers have used it as shellac thinner and for general cleanup without dropping dead in their tracks, as have dirt track racers with their alcohol-fueled hotrods.
Jerry

Acetone works fine, too, also a can be used as a thinner for epoxy if necessary.

Ed

Correction to my previous post. When the pan was cruddy and crusty, those repairs looked like epoxy. Upon cleaning, I see they have been brazed inside and out.

I don't think this part of your question was answered: 216 pans will not work on 235s.

That is not correct for 1940-1952 216 and 235 oil pans - they were all the same pan.

Some 1953 pans and all 1954 and later pans were different.

1929-1954 Chevrolet Master Parts & Accessories Catalog

The height of the oil troughs had to be adjusted on the 235 pans to accommodate the longer stroke crankshaft. Replacement pans for the 235 engine had "235" embossed into the pan in numbers about 2" tall.
Jerry