Model E transmission oil

[sparkymark]

I have a 1935 model E Cletrac and want to change the transmission and final drive oil. At TSC I find 80W-90 and 85W-140. Is one of these suitable?
  I have the original Cletrac Lubrication Recommendations book, and it mentions SAE 30, SAE 40-50, and SAE 60-70 depending upon the temperature.

[Robert Barbour]

Most 80W90 and 85W140 are GL5 gear oils that have EP additives that are not good for the band brake of the steering system.  Look for a GL 1 gear oil or use a SAE 50 motor oil.

[Blake Malkamaki]

The book calls for 50 wt non-detergent motor oil. My E currently has 50 wt detergent motor oil as I couldn't get the non-detergent the day I needed it. It steers very good, but then there is little weight on an E so it should steer easy.

Many on here use the GL-1 gear oil. I guess the choice between these two would be price and availability.

[oliverchris]

See the topic entitled 'Where to get transmission oil in Canada?'  on the HG, OC3, OC4 forum. That gives some products and prices.