borg warner auto trans.

[Johnnywiffer]

I may be mistaken but I seem to remember that the main reason for using 10W motor oil was so Studebaker could advertise "no special oil needed". If you'll recall, that trans was VERRRY advanced for its day. When Studebaker began working with Detroit Gear to build it, they laid down certain specs. I think the use of motor oil instead of trans fluid was one. Plus direct drive clutch, "park" and "reverse" lockout.

I can remember driving down the road at a good clip and to show off, flip the lever down into "R" to show that it wouldn't hurt the trans. Try that with ANY OTHER trans!

Granted, modern trans fluid is better in modern transes but I have used 10W for many Studebaker Automatics with NO apparent ill effects.

Once in the 50s I was on a trip, stopped at a station, checked the fluid which turned out to be about a pint or so low. I told the station guy, "Just get me a quart of 10W." Believe it or not, he refused to do it. "You can't put MOTOR oil into an automatic. I'm not gonna sell it to you." Had to go to the next station and didn't tell 'em the reason for needing the 10W.

However, I also seem to remember that about '52 or so, Studebaker began recommending Type A fluid for that trans.

John

[55studeman]

quote:Originally posted by Johnnywiffer

I may be mistaken but I seem to remember that the main reason for using 10W motor oil was so Studebaker could advertise "no special oil needed". If you'll recall, that trans was VERRRY advanced for its day. When Studebaker began working with Detroit Gear to build it, they laid down certain specs. The use of motor oil instead of trans fluid was one. Plus direct drive clutch, "park" and "reverse" lockout.

I can remember driving down the road at a good clip and to show off, flip the lever down into "R" to show that it wouldn't hurt the trans. Try that with ANY OTHER trans!

Granted, modern trans fluid is better in modern transes but I have used 10W for many Studebaker Automatics with NO apparent ill effects.

Once in the 50s I was on a trip, stopped at a station, checked the fluid which turned out to be about a pint or so low. I told the station guy, "Just get me a quart of 10W." Believe it or not, he refused to do it. "You can't put MOTOR oil into an automatic. I'm not gonna sell it to you." Had to go to the next station and didn't tell 'em the reason for needing the 10W.

However, I also seem to remember that about '52 or so, Studebaker began recommending Type A fluid for that trans.

John

I agree that it was advanced for the day, that is why I am particularly fond of it, like to rebuild them and keep them on the road, and brag to my non-stude friends about all of it's advanced features.

John I assume that you are using something better than 10w nowadays, and that you mentioned it to bring up an interesting highlight. I would like to comment on the 10w if I may, as some may still believe that this oil is best for the DG, when it clearly has been surpassed by better oil that is engineered for it.

10W was original spec oil for many of the early auto-trannies in the late forties/early fifties, but not because it's the best for it. Simply there was no other option -the mechanical engineers got way ahead of the fluid engineers. The Auto-trannies were so new and the complex fluid dynamics requirements were not met by anything else except 10w -even then it was minimal, at best. So when better stuff came out, then all the car manufacturers were quick to require actual auto-tranny fluid.

ATF is a real special fluid. It has unique requirements that seem to be contradictory. Let me detail a few, such as the fluid must lubricate (make slippery) the bushings and bearings, YET it must also have friction capabilities (non-slippery) to allow the multi-disc clutch packs to hold, and the direct clutch to hold without slip or chatter. Further more it must be a capable hydraulic fluid, thin enough to pump but not too thin to hold air and foam up.

Motor oil, is simply that, meant for a "motor." It is engineered with an additive package with specific viscosity modifiers, bases to combat combustion acids, and high pressure modifiers. There's no friction modifiers for auto-tranny clutches, no anti-foam agents to protect the hydraulic nature of the fluid, no viscosity modifiers for the tranny environment.

In conclusion, 10W will work in a jam, and it will work for longer periods too. But when used for long periods or with thousands of miles, it won't function as well as ATF. Motor oil in an auto-tranny is far more likely to have unusual and undesirable side-effets, such as clutch chatter, soft shifting or no shifting from foamed oil, gears that won't hold because the motor oil varnished the clutch friction surfaces, and etc.

Modern ATF (dexronIII or IV) is just perfect for out DG trannies. In fact DexIII+ ATF will shift better and hold the shift stronger, have less clutch chatter, lubricate better (which means better gas mileag

[tracker]

You guys are great! Thanks for all the helpful info.
tracker

[Johnnywiffer]

"John I assume that you are using something better than 10w nowadays,"

Yep. Last time I had my Flight-O-Matic redone, I forgot to tell 'em Type F, so they used Dexron. It seems to be OK after a few hundred miles. Shifts seem to be very firm. Frankly, if they would be firmer with Type F, I think it would shake the motor in its mounts.

Have not had to rebuild a Studebaker DG Automatic in a very long time but will use your recommendation when I do.

John