Loren Posted January 1 Report Posted January 1 Back in the 1980s ( a lifetime ago ) I was a dealer Saab mechanic and off road racer. Finding a lube that could keep a transmission in those old cars was a challenge. Even the factory was on it. I won't go into the evolution ( again ) of how we hit on lower viscosity oil and Redline products in particular. I have three vehicles that are coming up on a transmission oil change, two automatics and a 1949 Plymouth Overdrive. So I thought I'd start the selection process before need. The first is a 2013 M-B GLK 250 which is a 7 speed automatic which has a change interval of 70,000 miles. I didn't make it that far because it started slipping in high gear at about 60,000 miles. When I read the procedure it sounded more like an engineering project than maintenance. There's no dip stick/fill tube. You have to use a device to pump the fluid in from the bottom, then run the engine to warm up the transmission which you have to check with an inferred thermometer. Once it warms up the temperature determines the level. The torque converter has a drain plug but nobody drains it so the car owner only gets 50,000 miles till the transmission slips again. The second time I bought the equipment and did the change myself. It's near the change interval and no slipping. The Mercedes spec is designated as M-B NAG-2. A check of the Redline products indicates D6 ATF meets that spec. The second is a 2008 Ford F 250 Diesel. It is a whole lot simpler than the Benz but it requires Mercon LV. The Redline D6 ATF meets that spec too! Now we are getting somewhere! I like the idea of using one lube in as many vehicles as I can. Makes it worthwhile to use the better stuff. The Plymouth used to use GL-1 lube which surprisingly is still available. Over the years I have learned that if you want to clean the inside of a manual transmission before you rebuild it you can drain and refill it with cheap ATF. The inside will be clean as a clock! A quick read of the Redline D6 ATF spec sheet tells you it can be used in manual transmissions replacing all but GL5. The main issue with the Overdrive is the Sprag Clutch. Extreme Pressure ( EP ) lubes can cause them to slip and so that is why GL1 used to be spec'd. Automatic Transmissions use planetary gear sets and Sprag Clutches so we know ATF is compatible. Red Line MTF is plenty good for a regular 3 speed transmission and is a little cheaper. Plymouth transmissions are well designed and don't require crazy expensive lube oil. However if you put the money out for an Overdrive you might want to feed it the best you can get. My inventory of transmission lube just got much simpler. 2 Quote
Adam H P15 D30 Posted January 2 Report Posted January 2 Many manufactures switched from gear oil to ATF in the late 70s to improve cold shifting and a slight bump in fuel mileage. Mopar switched to ATF in their A833 around that time. So yes, I would feel comfortable using ATF in most manual transmissions but especially the O/D transmissions. Quote
Merle Coggins Posted January 2 Report Posted January 2 It seems that I remember that the ZF manual transmissions that Ford used in their Super Duty trucks called for ATF as well. Quote
TodFitch Posted January 2 Report Posted January 2 2 hours ago, Adam H P15 D30 said: Many manufactures switched from gear oil to ATF in the late 70s to improve cold shifting and a slight bump in fuel mileage. Mopar switched to ATF in their A833 around that time. So yes, I would feel comfortable using ATF in most manual transmissions but especially the O/D transmissions. I vaguely recall that the manual for the 1963 Dodge D200 I once had called for ATF in the manual transmission. So I think the transition from gear oil started earlier than the 1970s. Quote
Dartgame Posted January 5 Report Posted January 5 I'm a little confused. I looked at redlines website and see MTL, and ATF, but no MTF. Quote
Sam Buchanan Posted January 5 Report Posted January 5 17 minutes ago, Dartgame said: I'm a little confused. I looked at redlines website and see MTL, and ATF, but no MTF. Redline MTL is what you want, it works great in my '48 P15. It had crunchy 1-2 shifts when cold but the Redline yields very smooth shifts in all gears and temps. It worked so well my '74 TR6 and '69 Beetle now have MTL. 1 1 Quote
Dartgame Posted January 6 Report Posted January 6 Okay yeah that's what I've used in other manual trans cars. I was thinking there was a new product... Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.