VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Transmission Lube Question

I have a 47 Fleetline with an original 216 engine and 3 speed transmission. I purchased the car last fall and had no problems shifting between first and second gear (no grinding). However, my transmission lube has been leaking down the torque tube into my rear differential. I just added GL 4 140 gear lube to the transmission and now I am grinding when I shift from first to second gear.

Is the transmission lube that I added causing my grinding problem? What type of transmission lube should I be adding to the transmission? I heard that I need to be careful about the type of transmission lube due to brass bearings.

Any help is appreciated.

Thanks,

Perol

The GL 4 may have a sulfur additive. Most also have an additive to make the sulfur non-corrosive. I have used the GL 4 for years with no problem. The "heavier" 140 should slow down the spiining gears and actually eleminate gear clash. Years ago we used to put in 140 for the summer to eleminate gear rattle in reverse (minor clutch chatter) Did this when owner complained of the problem, even on new cars.
Most 1940-48 cars have gear clash on the 2nd to 3rd shift. This is caused by a weak syncronizer.
Any idea of what weigt was in the trans. when you got the car?
I really don't thing the gear oil has anything to do with it.....unless the level was very low before you added the 140.
My opinion :)

Gene,

I don't know what type of gear lube was in it when I purchased the car last year. The level was low when I added the gear lube. I drove it yesterday without any problems, so maybe it fixed itself. Can I ask what type or weight of gear lube you use for the transmission on your 39 chevy?

Thanks for your help.

Perol

I use 85-140 as it covers the lower temp. range as well as high temp.....never know what to plan for in this part of the country. 140 is just fine for above 50 degrees.
Something may have been running dry when the fluid level was low causing more friction and slowing down the gear rotation when shifting.

You should address the problem of th eleak down, an "Oakie" bushing which is a one piece replacement of the bushing and seal at the front of the torque tube is an easy and lasting fix. I am with Gene I use 85/140 synthetic in the 52.