Transmission Fluids & Lubricants

Eaton Fuller Transmission Fluid: PS-386 and PS-278

Genuine Eaton PS-386 synthetic transmission lubricant in a 1 gallon jug (K-PS386-BOX), a case of four 1 gallon jugs (5564546-M4), 5 gallon pails (K-PS386-PAIL, 5564543M) and a 55 gallon drum (K-PS386-DRUM, 5564544). PS-386 is the lubricant Eaton specifies for its Fuller manual transmissions (RT, RTLO, RTO, FR and FRO series), Fuller Advantage, UltraShift PLUS automated transmissions and Endurant. It replaced the PS-164 rev 7 specification on January 1, 2017, and Eaton states the two may be mixed for top-off. PS-278 (K-PS278-PAIL, 5 gallon) is the lubricant Eaton specifies for the Procision transmission only; Eaton says not to use it in other Eaton models.

Which fluid goes in an Eaton automatic?

UltraShift PLUS and Endurant automated transmissions take PS-386. Procision, Eaton's dual-clutch automatic, takes PS-278.

Older SAE 50 fills

If the unit was last filled with an SAE 50 transmission oil, Eaton's extended-interval lubricant for the same transmission is PS-386. Do not mix standard and synthetic oils; drain completely when switching, and use no additives or friction modifiers. Using PS-386 is part of the Reman Bundle warranty registration on our Eaton reman units.

How much does it hold?

Heavy duty Fuller models hold 23.5 to 29 pints (about 3 to 3.5 gallons), so a 5 gallon pail covers one change. Model by model figures and the fill procedure are in our Eaton Fuller transmission fluid and oil capacity guide.

Axle and differential lube

Eaton 75W-90 axle lubricant (K-75W90-BOX case of four, K-75W90-PAIL 5 gallon) and Dana Spicer FE 75W-90 (FE75W90-P) and XFE 75W-85 (XFE75W85-P) synthetic gear lube for drive axles and differentials.

Rebuild kits, seals and gaskets for the same units are in Eaton Transmission Parts; complete units are in Eaton Fuller Transmissions. Not sure which spec your transmission was filled with? Call 877-776-4600 with the model tag.