Every now and then someone asks about buying an overdrive transmission at a swap meet or e bay. Photos are shown with the transmission cover plate off showing the gears. The planetary gear is in the tailshaft housing and I've never seen anyone show a picture of that. Here's some pictures of an R-10 overdrive planetary gears that have been ruined by a lack of oil in the transmission.







I bought a transmission at Carlisle with a bad planetary gear.I was able to salvage the cluster gear out of it and put it in another transmission.

I've ruined 2 planetary gears myself by having the oil leak out and not recognizing it. It makes an awful crack going down the highway when those gears seize up.

I wouldn't buy an overdrive transmission unless someone shows the planetary gear inside.

  Dennis in Lititz PA

Dennis.  You bring up a good point about the overdrive trannies.  I too have wasted the overdrive planetaries before realizing that the overdrive portion of the transmission had its own oil fill and sight level hole.  Since then, I’ve modified the main case and overdrive section with a shared oil transfer hole at the bottom of the cases so I could check the level of either at the main case sight hole.  And thanks to a suggestion by Doug T. I was able to eliminate the oil leak at the overdrive solenoid with an improved seal design.  I took this a step further and installed two seals back to back in the solendoid shaft hole in the tranny which totally cured all leaking from the transmission.

Lorena, Texas (South of Waco)

I learned that lesson about 45 years ago. Back then I drained my oil every Saturday morning and checked both fillers. The ruined tail section I learned the lesson from was on someone else's car. Thank goodness it wasn't one of our stations that did the last lube job on it.

Kenneth

Fredricksburg, Texas

Previous owner of my car tried to cure leaking solenoid seal problem by plugging the solenoid drain hole with RTV. As a result, oil filled the solenoid and made it non-functional (FYI: be aware, since the unit can be installed 180 degrees from correct location, same thing could likely happen with drain hole pointing up).

Re: the separate OD drain & fill holes: This has always been a source of confusion for me. Since the trans.gear & OD cases communicate oil directly, how is it possible (with oil flung from spinning gears) for only one to run dry? My 55 shop manual warns that both cases should be filled ONLY through the trans hole. Yet, if the car is level, the OD fill hole is noticeably higher. As a result, I have been filling both through the OD hole, and stopping when it runs out the trans. hole to insure the OD is filled, but not overfilled.

The people that rebuild my trans. overfilled it big-time with synthetic lube, and I ended up with a contaminated clutch disk that inevitably grabs on prolonged hot-weather drives.

6 VOLTS/POS. GRD. NW INDIANA

Dennis,

Thanks for the information - very helpful. Especially since I am investigating whether or not to run one of these on my 55 Sunliner. How much are those planetary gears going for these days? Is the R10 and the R11 planetary gear the same part number?

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Ford as well as Hollander lists 2 different part numbers.

Kenneth

Fredricksburg, Texas

R10 has 3 planetary gears, R11 has 4.  That alone would change the part number.  Don't know if they interchange.

John - "The Hoosier Hurricane"

Dan, as John says, 3 gears verses 4 gears. I've never held an R11 in my hand so I don't know if it would work.



The planetary gears come up on e bay every now and then. I've bought 5 that way. The most was about $115. the least about $38. I got one recently that was listed for a studebaker transmission, only one other guy bid on it. As long as it's an R10 from a borg warner I know it will fit mine.

  Dennis in Lititz PA

Dan T, the last planetary gear I ruined, the oil leaked out of the overdrive unit through the rear seal on a trip to Virginia. Plenty of oil in the rest of the transmission. I had replaced the rear seal and thought I had the problem solved.



I thought that the transmission doesn't share an oil passage between the overdrive and the main gearbox. I didn't see any when I had mine apart to build it. [ I had to put the truck input shaft into a car transmission ].



The 1st time I ruined a planetary gear, the truck set over winter. When I backed it out I saw the oil stain on the cardboard, but didn't put 2 and 2 together. It leaked out of the solenoid that time. That solenoid shaft gasket is available now from different suppliers.

  Dennis in Lititz PA

My Borg Warner T-85 did not have the capability to share oil between the gear box and the overdrive section.   I suspected as much when the overdrive section burnt up and the gear box side was still full of oil.  I simply drilled a ¼” hole in both cases at the bottom to insure that the oil would share between both sections. I also put a corresponding hole in the gasket that mates the two together.  When first filling the tranny after rebuilding it, I initially filled both sections as designed but simply only check it now at the gear box fill hole and not the overdrive fill hole.

 

On another overdrive tranny that I took apart and rebuilt, the shared oil passage was there in both cases but the gasket didn’t have the hole.  I put the hole in the gasket so both the overdrive and gear sections would share oil levels.

Lorena, Texas (South of Waco)