VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1937 Distributor

I need to confirm some information about the distributor in my 1937 Master Coupe (GB). I have taken it part, cleaned it, and am ready to put it back together. It appears to be in very good condition. Both of the advance mechanisms moved freely and the vacuum diaphragm works great.

The tag on the distributor has the part number 649GX and serial number 3820. Based on the spec sheet for a '37 this appears to be the correct distributor. However I am a little confused by the part numbers in the parts catalogs.
-My 1940 parts book says that 1937 was the only year that used part number 1864485.
-My 1948 parts book shows the correct part number for a 1937-1939 is 1110008.
-And to make it more interesting that is the number shown for 1938-1939 in the 1940 parts book.

Also I am still trying to figure out the grease cup. When I took mine apart there was no spring or wick in the distributor body. The parts book listings are confusing. It appears that there are 2 wicks that fit the 1937. The 1941 book lists part number 816803 for 1929 to 1940 and 802692 for 1934 to 1939. There is only one spring listed, 1845715.

It was interesting to see that the distributor shaft was worn in the area where the grease hole in the distributor housing. My guess is that the grease or wick got hard with age and did that. In any case the shaft is fine in the bearing area with no side play.

Any information on either item is appreciated.

Thanks,

I don't know much about 1937 distributors but do about parts books. Typically if changes are made in a part or assembly (like from the '36 to '37 distributor) the assembly and parts will be listed in the parts book dated the same year and possibly some later years. Once the number of parts available have mostly been depleted then a "replacement" part will be listed for that year and model. That is even if the part or assembly is not an exact match. Guess the rationale is "better something that works" versus an identical match. As you can imagine it causes some confusion when it comes to restoration and judging.

Chipper is correct - the later parts books list the available units that will fit the application at that time. Parts would have been consolidated.

According to my information & books, the correct distributor for 1937 is a 649G. I don't have any listing for a 649GX, either in my Chevrolet literature or in the Hollander's catalog.

It's been a while since I had my '37 distributor apart, but I don't recall any wick or spring in the grease cup. The shaft is lubricated be turning in the cover until resistance is met, which forces the grease to the shaft.

Hope this helps.
-Bob

Actually, there is a spring and a wick in the distrubitor housing behind the grease cup. The wick rides on the turning shaft and the spring pushes against the wick to hold it in place. Many times both the spring and the wick are missing. When the wick is worn out and gone, the spring is usually removed because with the wick gone the spring will ride against the turning shaft causing wear to the shaft.

The original 1937 distributor could have a problem. Oil can be forced up past the out side of the housing where it passes through the block. The "fix" in 1938 was to add an extra grove in the housing + an oil drain hole.This improved unit was used in 1939 with no changes. Chevrolet sold the 1938 unit for 1937's once the stock of the 1937's was exhausted

As far as judging is concerned the distributors all look the same externally....numbers don't count.

Thanks everyone for confirming this information.

-I now better understand the logic behind parts book listing. That is one of the reasons I bought an "earlier" (1940) parts book as well as having a 1948 and 1954. It helps fill in the gaps. That is a lot easier to do today with computers, databases, and systems. In our business we keep records we call "sub to" and "sub for" to track this evolution of service parts.

- The "X" is permanently printed on the tag on the distributor. The designation "649G" is stamped. So I am fairly confident I have the right one.

- And the explanation of the spring and plug makes perfect sense, especially with the wear area on the shaft. I wonder if the spring actually was worn away.

- In this case Gene there is no indication of the oiling problem you describes. I'll watch for it when I finally get things going again.

I plan to re-assemble the distributor without the spring and "wick" for now. That is something I can take care of later.

Great guidance, and one of the many valuable benefits of VCCA membership.

From 1940 and up there is a little baklite disc that rides against the dist. shaft.
This "spring system" was added in 1934. It was to keep a steady pressure on one side of the shaft "prevent misfiring due to variation in firing between cylinders , caused by excessive clearance due to manufacturing variations or or wear".

Thanks Gene!

I am assuming that I can put the Bakelite button and spring in my distributor without any problems. I would prefer to have that rubbing against the shaft rather than the end of the spring.

Everything went back together nicely.

Another fix I have done on Chevy distributors is to add shims between the top of the drive gear and the bottom of the housing to limit the up and down motion. I leave about .005" to .010" clearance. This minimizes any timing variation if for some reason that gears try to move up and down in relation to each other.

Actually, the distributor shaft should move up some when the distributor is inserted into the block. With the oil pump thrust washer in place on top of the oil pump assembly the distributor gear and shaft to move up, thus raising the weight plate inside of the distributor so that it won't rub on the bottom of the distributor housing when it is rotating.

Thanks Junk Yard Dog for the note about allowing the shaft assembly to move upward. I noticed that there was no sign of wear on the face inside the distributor housing or the bottom of the weight plate

Right now there is quite a bit of movement. But I do not want to make things bind up.

What does actually push the shaft upwards and determine the height of the shaft? Does the face of the hub of the gear rest on the thrust washer on top of the pump?

Yes, the bottom of the distributor gear rests on top of the oil pump thrust washer. The thrust washer is what sets the correct spacing for the weight plate when the distributor is in place. If shims are inserted between the top of the gear and the bottom of the distributor housing then the gear and shaft assembly cannot move up the correct amount as dictated by the thrust washer. Instead, the distributor housing will sit higher than it should.

No, I am refering to the disc that is placed into the grease cuo opening firat and rubs against the side of the dist. shaft. The disc is held by the spring and grease cup. It was new for 1940. Its part # 1869303 in GR 2364. (from 1952 book) In the 1941 bok its described as "plug(fiber) in grease cup hole.
There is also a wick in the center of the dist. cam under the rotor.....that gets oiled every so often. It for the automatic advance

Thanks Gentleman.

I apologize for creating confusion by having 2 strings going in the same topic.

Junkyard Dog got me straight on the vertical movement of the distributor shaft. And thanks to Gene I know what I need to control the side movement.

Cool! Glad that we could help you out!