I have a '46 pickup with "53 235. After installing an Okie bushing in my torque tube, I went to a car show that was 100 miles away. Everything went well with the gear oil and the seal. Thanks for all of the advise on this great forum.
I was going on mostly back roads at about 50-55 mph. Cruising well but maybe a little above its "comfort zone". When I got to Sea Isle City, NJ, I checked the oil and I was down almost a quart.(but the undercarriage is well lubricated ) I'm fairly certain that's if it's burning any oil it is minimal. I do have a a small rear main leak but almost all of this leak is coming from the draft tube. There are no baffles in the tube itself and I really do want to keep this truck as stock as possible. I have seen, somewhere, about installing some sort of device/baffle/mesh in the tube to slow this down. I'm not really keen on the pcv valve idea as I promised my Dad that I would keep his truck as stock as possible. If I can do something before the return trip in two days, I could get a good test trip when going home. Any comment are welcome. .
1946 1/2 ton Chevy Pickup 1954 235 cu in 3 speed on the floor
"In actual fact, there was a stock PCV system available on some AD models in 1954, but good luck finding one!" (Deve)
There are minor (somewhat insignificant) mistakes in Deve's write-up :
- a PCV system was available on slow-moving delivery trucks as of 1948 and later years (it became standard equipment in those slow-moving, door-to-door milk/bread delivery trucks {"step vans")).
- a PCV system was available as an option on ALL model 1954 trucks (and probably later).
A PCV system is a very valuable (necessary) item if you do a lot of slow-speed, and/or, stop and go driving. Using/adding a PCV system, if done properly, causes no harm. However, there is no need to add one for most old trucks, that have engines in good condition.
Consider your driving conditions, and do what you have to do (and, if you do not need the system, do what you like).
As a temporary fix, you can pull the tube and stuff a copper or stainless steel pot scrubber pad in there to act as a baffle, assuming the factory in-block baffle ha gone missing.
As a temporary "get it home" fix, stuff a Chore Boy scrubber down the draft tube. Once you get it back on your home turf, deal with the real problem- - - - -an engine with enough blowby to push oil out of the draft tube is way overdue for a ring job. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I just got back from the grocery store and got a stainless steel scrubby and put in the draft tube. We'll see how much this slows down the oil leak.
I have been thinking about "WHY" this is happening. I will adjust the valves and do a compression check when I get home. I agree. That is way too much oil to be losing.
1946 1/2 ton Chevy Pickup 1954 235 cu in 3 speed on the floor
I'd recommend a cylinder leakdown test instead of or in addition to a compression check. Roll the engine over until the distributor rotor points to a plug wire, put the transmission in high gear, set the parking brake and/or chock the wheels, and put air pressure into the cylinder through the spark plug hole. Most compression testers with screw-in pressure hoses can be adapted to do this. Listen at the carburetor, tailpipe and oil filler for air leaks. Follow the firing order around to test all the cylinders for leakage. If you set the air pressure to 100 PSI with no air flowing, the pressure the cylinder maintains will give you a "percentage of leakage" number. For instance, a cylinder that holds 90 PSI has a 10% leakdown rate. I like to see 5% or less on a healthy engine. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
OK, So I just got home from the Jersey shore. It's about 100 miles. I checked the oil and the $4 dollar fix worked. My favorite kind!! I didn't blow any or little oil out. The dipstick measured the same as when I left this morning.
1946 1/2 ton Chevy Pickup 1954 235 cu in 3 speed on the floor
What's the possibility the baffle under the draft tube down inside the crankcase might be missing? That will allow oil thrown off the crankshaft during normal running the be thrown up inside the tube where it can get siphoned out by the airflow of highway driving forming the vacuum that it's supposed to at the end of the tube. Below 20-30 MPH there's not much vacuum, so the oil loss will only show up on a road trip, not around town.
The baffle is held into place by two machine screws (stove bolts) through the side of the block just below the draft tube hole. If those screws are missing, oil can leak out of the holes, also. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I would guess that the baffle is NOT there. I was cruising along at 50 - 55 mph, same as the trip down. I'm a little leary about pulling the tube from the block since it seams to be leak free. How is the baffle attached? I assume that it's in the block. Is that correct? The bolt that I can easily is there and looks good. I'm still going to the check the valve adjustment, compression ,and leak down because I just need to know.
1946 1/2 ton Chevy Pickup 1954 235 cu in 3 speed on the floor
The baffle is inside the crankcase, a sheet metal deflector attached by two screws through the side of the block. You'd have to drop the oil pan to definitely confirm it's there, I believe. You might be able to get an idea if it's in place by inserting a piece of stiff wire down the oil fill hole and measuring how far it goes before encountering an obstruction. If the baffle is there, the wire should stop within an inch or so below the bottom of the draft tube.
In the photo above, one of the baffle attaching screws can be seen between the pushrod cover and the fuel pump. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Either your your baffle is in there, or someone went to some extra effort to find a way to keep that screw in your picture in place. Those sheet metal screws thread into the sheet metal baffle itself. The hole in the block where the screw passes through is just that, a hole (no threads in the block).
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
The road tube on my 56 is just a snug fit into the hole with a small support extension and bolt off of the tube running down that attaches to the side of the block. If I remove the bolt, I can easily lift out the whole draft tube and look into the pan and see the blocking shield. Lee.
You guys are the best. What a wealth of knowledge! I am going to work on the engine next fall and winter. I only go to local shows around the Philadelphia suburbs and not even that many. I am going to go with the stainless scrubby for the summer. I know that I am getting too much blow by, but I can live with it the way it is for now. At least l won't be leaving a big oil stain when I park at a show. My wife wants a new kitchen countertop and a new porcelain tile floor. That will be my next project this summer. Happy Wife, Happy Life!
1946 1/2 ton Chevy Pickup 1954 235 cu in 3 speed on the floor
If I look at your draft tube, there is a baffle in there. If you look down the tube you will see little holes. Those holes feed into the space between the inner tube and the outer tube. This is how gases are supposed to flow around to the side tube. That top ridge should provide a seal between the two tubes. It appears that someone has torn and bent that lip and created a direct passage to the outside tube. That is probably why you are losing oil.
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