ford Y block overdrive?

I have a ford Y block 272 with overdrive..I have been using overdrive for quite a bit with no problems.But the other day while on freeway it kind of slammed out of overdrive without me trying to do so..I pulled of freeway and now can't get into overdrive what soever..anybody have any ideas what the problem could be?..

 

The overdrive unit is at the rear of the transmission housing. It sounds like the unit has lost its method of activation. Is yours a pre '56 vehicle? I'd start by talking with a good local transmission technician who is experienced in those set ups. They were not very complicated but many who are newer probably don't know where to begin.
Normb9

 

You know anyone in Bay Area ?

 

It is @ 1955..converted to 12v

 

There are some great links posted near the end of a thread on these transmissions. Search: 1950 Merc overdrive transmission bench test. Great info. Hope it helps you or a trans guy you find.

 

Cool..thank you. I will check them out!

 

Way back in the early '60's, the overdrive in my '54 Ford also unexpectedly dropped into direct while driving on the highway, never again to engage in OD. Upon tearing the unit down, I found the planet gears had egg shaped and would no longer turn. The apparent cause was worn out shaft bushings in the planet gears. The local Ford house would not sell me just the planet gears, although I was successful in dis***embling the gears and carrier. Wish I hadn't spent half a day taking the damn thing apart. I had to buy the gear ***embly. Seems like it was between $30.00 and $40.00. Doesn't seem like much today, but it was a pretty good kick for a high school kid making $45.00 per week. Hope yours turns out to be something simple as I expect Ford no longer supplies the planet gear ***embly.

 

I'd look at the fuse first, but even if it's blown there had to be a reason for it to blow. These transmissions are pretty hardy, but the old electrics need to be well maintained for it to work.

The relay or the solenoid may have ****ped out.

There's plenty of information on the Borg Warner overdrive both here and elsewhere. I suggest you get a Green Bible for your car or a transmission manual for the BW.