What type of transmission oil for 1928 Studebaker Dictator - Straight cut gears

Any ideas? I am having trouble shifting the car and i think a light weight tranny oil was put in.

I was just told to use 90W Mineral oil for the bronze worm drive rear end of a 1934 Nash Ambassador and it was the thickest stuff I've ever seen. Should I be using that??

Thank you!

Keith Gramlich

My brother is running straight 250w in the gearbox of our stude ge. It's a little stiff in cold weather but the heavy oil stops it leaking too much out of the gear selectors. If your going to use it when it's cold 90w works well, our 1929 Plymouth shifts great in below freezing weather with 90w oil.

Thanks!!Should that be regular 250W gear oil or mineral oil? The reason I'm asking is that the 90W mineral oil is, I think, thicker than the 600W stuff Snyders has for model A's.

Straight mineral oil with no additives.

Terry

What dictator27 said. The stuff we use is straight, non ep gear oil.

http://www.morrislubricants.co.uk/scripts/prodview.asp?idcat=140&idProduct=27

This is great! Thank you! Any idea where i can buy this stuff in the US?

You can probably order it from your local auto parts store like NAPA but it won't be a stock item, probably have to wait a day. Last time I bought straight mineral gear oil it only came in 5 gallon units.

Napa part #65-205 GL-1 90w gear oil. I don't know about the US, but it is also available from Volkswagen dealers here.

Terry

What dictator27 said. The stuff we use is straight, non ep gear oil.

EP additives were developed about 20 years ago that do not attack brass and bronze. This was required for gearboxes with baulking ring synchromesh - the baulking rings are brass or similar. You can read about this on http://www.widman.biz/Corvair/English/Links/Transaxle.html.

Based on what Richard Widman says in the referredpaper, you can use a GL-4 oil designed for synchomesh manual transmission. Make sure you get one with all the other additives too, including anti-corrosion and anti-foaming. Note that the old designations GL-1 to GL-3 are obsolete and are not tested. They may still be marketted, but they don't necessarily comply with those designations.

http://www.grainger.com/product/MOBIL-Gear-Oil-1MUC8

Also available in 5 Gal pails from auto and fuel oil/lubrication distributors. Use a large suction syringe to dispense into tranny:

http://www.amazon.com/Sealey-Oil-Suction-Syringe-500Ml/dp/B004ZFDBMU

Thank you very much all!! I will look into all this and see what we have come drive time next season. I very much appreciate the help everyone has given!

Best regards,

Keith