3 speed Easyshift with Overdrive, what lubricant?

[Florida Marty]

Like many before me, I have searched this site for a definitive answer, and cannot find it. Maybe my inexperience. I know this topic has been covered here before, but most of what I have read here, still did NOT directly answer the question. I don't mean to sound critical, far from it, I just am trying to get to the bottom of it, so I can avoid a costly mistake.

 

I hope one of you holds the key to the confusion.

 

I have a 1953 Meadowbrook Suburban, with original factory Flathead 6 cyl, 3 on the tree, and overdrive. The factory Dodge shop manual says to use SAE 10 W engine oil to fill both the overdrive and trans units under section 13-lubrication. Later in the book, section 18-overdrive transmission, it says to use SAE 80 lubricant. The capacities also disagree. I have searched the web, and fifthaveinternetgarage seems to be the most knowledgeable, but they say to use only SAE 90 in a BW R-10 overdrive. I inquired via email, but unfortunately Randy Rundle, the site's creator, has passed away. His widow recently explained she is unable to offer solutions other than what Randy had posted. RIP Mr. Rundle.

 

So in closing, thank you to all of you. I hope someone can assist me, and one day I can return the favor.

 

Thank you.

 

 

Edited January 11, 2022 by Florida Marty
wording

[greg g]

Been running gl1 rated multi viscosity  I think it's 70  90 not sure without looking at the bottle. I have about 14 k miles since I swapped in the 56 three speed and the 54 r10 over the last three driving seasons.  Both seem to be operating well and have had no issues. The od might engage faster with the motor oil but several folks who have OD tell me its very comparable to how theirs engage. GL 1 grade is recommended as these units as well as earlier have brass and bronze pieces in the synchro.  Later lubes made for hypoid gears have shear strength enhancing additives which don't play well with yellow metal pieces.  As to how long it might be before any il leffects arise is guesswork.  You can gl1 multi grade  gl 1 from Napa, its Valvolene or Castrol if memory serves and was maybe 8 to 10 bucks three years ago or maybe 17 fo a gallon.  You need about 2.5 or 3 pints for each section of the units.

[Florida Marty]

Thank you for the information.

[Florida Marty]

So I have now spent way too much time on this topic, but feel I have found out enough about what new and old lubricants are acceptable for this application. Thank you to Greg G for all his help. From my limited research, It appears Sulfur additives are the main concern and widely used in newer formulated gear oils to help control heat. The sulfur activates at somewhere above 200F and at that point, becomes most damaging to yellow metals. GL-4 gear oils, mostly DO NOT contain sulfur and are largely recommended for gear boxes containing yellow metal. At least that's what my research reveals. GL-5, does contain sulfur. Plain old GL-1 rated gear oil is still available and preffered, but harder to locate, and kinda expensive at this time. I just checked NAPA today, and they want $32.99 per gallon of GL-1, SAE 90 here locally. Other brands of non sulfurized, SAE 80-90, GL-4, I found today as low as $10 per gallon. Since yellow metal is pretty much the only concern, I surmise the GL-4 would be advantages as most if not all are EP type, recommended for gear boxes, steering gears, rear axles, conv rear diffs and rear diff's including limited slip. Maybe GL-4 would allow for just stocking 1 type gear oil for the rear diff, the OD, and the manual trans. I realize some of you are traditionalists and I respect that, but just maybe there is more than 1 correct gear oil for this application. I would love to hear other's opinions. Thank you to all!

Edited January 11, 2022 by Florida Marty

[Plymouthy Adams]

I believe in the GL4 the sulfur is out but the phosphorus is the sheer additive.  Not long back I bought a gallon of GL-1 from NAPA and it had gone up but not over 20.00 a gallon.  Used to be money talked, now it just goes without saying.  Also, our local Napa seems to have about 3-4 price tiers depending on how frequent you visit.   

[Sniper]

1 hour ago, Florida Marty said:

I just checked NAPA today, and they want $32.99 per gallon of GL-1, SAE 90 here locally. Other brands of non sulfurized, SAE 80-90, GL-4, I found today as low as $10 per gallon

 

Not sure where you are finding a gallon of GL-4 for under $10, $20 is as cheap as I could find it.  I can find quarts of it under $10 though.

 

For the $12 difference I'd just get the Napa GL-1 as called for.

[Florida Marty]

Phosphorus as an additive is actually a good thing from what I understand. It creates a coating on yellow metal and protects it from corrosion. Just something to consider.