Transmission / Overdrive: Synthtic Gear oil in T86 with OD

[63looks59]

Hello all---- I know Syn gear lube 75-90 is used in these old manual trans----
yet , is such a fluid OKAY with a trans WITH Over Drive ?

[62champ]

As long as it plays nice with bronze, you should be good. I have run RP full synthetic in my Champ since 2007 with no issues. Before, if the temperature was less than 40, it would almost roll in neutral the oil was so thick - now it shifts great, even with temps in the teens.

Make sure you drain and add fluid to both the transmission and overdrive. Family drove Studebakers starting in the 1940s, and my dad said the only time they had a problem with an overdrive is when it ran out of lubricant.

[Bud]

I've been using SAE 50 synthetic manual transmission lube meant for big truck transmissions in both the T10 4 speed transmissions and the T85 and T86 overdrive transmissions with great results for years. The Fuller Road Ranger transmissions require a lube that doesn't use extreme pressure additives so the manual truck transmission lube works well in old Studebaker transmissions too. Bud

[blackhawk]

I have been using AmsOil Synthetic Manual Transmission & Transaxle Gear Lube 75W-90 in my T86 OD transmissions for years. ~ Dale

[jackb]

10 years... many miles...... grandpa says: ..... what kind of miles have these lubes been in service ??? How could an engine with no oil filter and poor oils ever survive to 80K miles which was usual for Stude engines back when. More importantly to the thread at hand: Has anyone ever seen an OD tranny go bad using straight 90 wt. EP oil ?? Tell us what it looks like ..

"Family drove Studebakers starting in the 1940s, and my dad said the only time they had a problem with an overdrive is when it ran out of lubricant... "

[Son O Lark]

Looks like one vote for Amsoil. Any other brands also recommended? Also are there known brands to stay away from?

[JoeHall]

I have been running Redline MT90 for about 15 years in all T85s, and love the results. Smooth shifts even when the Studes are cold, winter and summer. I tried after Ted Harbit posted on here about it. Will never go back to anything else.