Top shift transmission.

[Randy1944]

I got great advice earlier and would like to get more opinions. I have bought the Van Pelt book on these transmissions. I have a stock 39 pickup with a top shift transmission that pops out of gear on occasion. I have bought what appears to be a late forties top shift transmission that is in pieces. The cluster gear has a broken tooth. I have decided to rebuild this transmission into a unit that I can use as a backup for my 39 pickup, that has a closed drive shaft. I have found that I need to find a Main Shaft Bearing Retainer #78-7085 B. Then I need to replace the Main Output Shaft #7061, to convert this transmission into one that will work on my closed drive shaft. Then I will need another Main Cluster Gear to replace damaged one. Am I better with used parts or new parts? I expect to buy new bearings and other worn items but am concerned with the meshing of new and old parts. Thanks for advice and especially help with sources for used parts if I go that way.

[Bob C]

Van Pelt will have the parts you will need.

[rockfla]

BobC X2
Mac VanPelt is "THE" man, get your parts from him!!!!

[Seth Swoboda]

You are using a 4 speed open drive transmission? When you say late 1940's, top load transmission, I can only think of a 4 speed truck transmission. These transmissions are not useful for your application.

Also, why build a spare transmission? Just curious. Why not just repair the '39 transmission that you have? It will give you years of good service.

[Randy1944]

I may have mis spoke. The spare is a three speed just like the ones in a 1948 pickup.

[cas3]

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open drive 1/2 ton 3 speeds started in 42 I believe.

[rotorwrench]

That cluster gear was around for a long time. The 1936 up type has a different locator set up on the back for the thrust bearing than the later ones used up into the early 50s on Mercury cars and pickups. They have little flanges that stick out to keep the thrust bearing turning with the cluster gear. Both are interchangeable but a person has to have the thrust bearing to fit the cluster they have. Mac VP sometimes has good used ones but it sure wouldn't hurt to have a new one. Mac has the proper replacement snap rings too. It's a must to get his snap rings and his thrust washer set up. Also make sure that the second gear bushing is a good fit to the main shaft and that the two parts properly work together. There were several types.

Pickup transmissions were basically unchanged from 1939 though 1950. The gears changed in 1951 for all the light duty 3-speeds. By 1951, all the cars had the 259 series light duty types with the small input and the long output. Pickups kept the light duty up into 1952 but the gears were all different.

[Tim Ayers]

Originally Posted by Seth Swoboda

You are using a 4 speed open drive transmission? When you say late 1940's, top load transmission, I can only think of a 4 speed truck transmission. These transmissions are not useful for your application.

Also, why build a spare transmission? Just curious. Why not just repair the '39 transmission that you have? It will give you years of good service.

Seth,

As others mentioned, the top loader, "light-duty" open drive three speeds were used in a lot of 1/2 ton trucks starting in '42.