3 speed OD question

[Greg58]

Dang...I don't think I'm smart enough to remember everything I'll have to do to drive with overdrive! I've got a friend with a F100 with o.d. so I'll check his out and ride with him to get a first hand look at the operation.

[rotorwrench]

Getting the hang of the operation doesn't take long. Most operations are just let off the gas when you want it to shift. When you stop at a stop sign, the unit drops out of OD due to the governor.

Many of the suggestions from Ford were to start out in second gear and do a normal shift up into overdrive for around town driving. This was as close to having an automatic transmission as Ford had in 1949. You only had to use the clutch when you stop & start. For highway driving, you shift normally up into high gear then do a normal shift into OD.

The one thing I can't stress enough that you have to remember is when parking on hills (mostly downhill), always shift the transmission into reverse. With the freewheeling unit, these cars will roll and sometimes they will overpower the E-brake. Mercury cars were more prone to this due to there weight but it can happen to any of them. My brother found this out the hard way. It didn't hurt the Merc all that much but it totaled out the car that it hit.

[tubman]

I had a '51 with Overdrive when I was in High school in the late '50's and it was the "cat's ass". This was a 6 year old car my dad bought off of a used car lot in 1956, so it was almost a new car (in the parlance from those days). In my opinion, trying to "shortcut" the original operation is foolish; I have one I'm going to put into my '51 and I can tell you after getting all of the parts I need that is not difficult. The B/W overdrive is well documented and the parts supply is adequate and not overly expensive; the solenoids excepted. I have been able to find four transmissions with good solenoids at swap meets over the last several years, for a lot less than the prices on eBay for solenoids. I would advise against taking any shortcuts, however attractive they may seem.

[JLford]

Originally Posted by 40 Deluxe

Well, once the trans is in overdrive, the cable cannot be pulled out so that's not a problem. Once you hit the kickdown and it goes back to direct drive you can pull the cable out to lock the trans in direct drive. This was recommended procedure in owner's manuals of the day for descending steep grades, for better engine braking. When approaching the downgrade, briefly floor the gas to kick down to direct drive, pull the cable out, then back off the gas. Actually, the only thing to avoid would be pulling the cable out ('lockout' position) when freewheeling (foot off the gas at any speed below 27 MPH).
Your toggle switch may cause some problems. When you're running at highway speed with the switch off, the trans will freewheel whenever the accelerator is released. So you will have absolutely zero engine braking!
If you forget to turn the switch off when coming to a stop on an uphill grade, the trans is still in overdrive and will not, cannot, roll backward. The overdrive planetary gears are such that they physically cannot turn backward when in overdrive mode (like in two gears at once). This puts a bind on the gears that they were not designed for. Could get expensive!
Also, if the car ahead of you rolls back, you cannot get out of the way! The shift lever will not go into reverse. It is physically locked out by the lockout lever through internal linkage. (Ask me how I know!) I had a toggle switch too, until a car ahead rolled back into me. This, plus trying to start uphill from a stop sign in low overdrive convinced me it wasn't such a good idea.

40 Deluxe, are you saying that with the overdrive cable depressed, the car should not free wheel unless currently in OD?

[Drbrown]

PARTS: Lloyd E. Young in Winchester, Ohio, phone 614-837-7832 recently told me he has numerous OD parts for sale. Don't know what parts, but he spent most of his OD rebuilding career on BW's. He's also a machinist and use to custom make OD parts.

MANUALS: Have four different BW manuals in PDF format if desired. Understand Ford used and copied BW OD designs.

My '47 has a BW B10 without kick-down switch; Just the pull-out handle to engage the OD and a toggle switch to activate it. Its 12v and uses a 30 amp Bosch relay. Can't move handle if car is in motion and free-wheels under 28 mph.

[40 Deluxe]

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Originally Posted by JLford

40 Deluxe, are you saying that with the overdrive cable depressed, the car should not free wheel unless currently in OD?

By "depressed", I assume you mean pushed in. This position allows the overdrive to function but does not "engage" overdrive. Engagement is done electrically.
But let's begin with the car parked on your driveway with the engine off. Now pull out (rearward) the overdrive cable and go for a drive. The trans will operate just like a plain 3 speed standard transmission. The overdrive function is "locked out" completely. Next, push the cable in (toward the dash) and accelerate to about 20 MPH. Take your foot off the gas, and the engine will drop to idle while the car just coasts, or "free-wheels" because overdrive is not engaged yet. This is allowed by a sprag unit within the overdrive. The electrical part of the overdrive is off (or inactive) until turned on by the governor (usually at 27 MPH). Accelerate to about 30 MPH (or more) and let up on the gas momentarily. You will feel the overdrive engage, engine RPM will drop, and the car will no longer free wheel if you let off the gas.
Whenever you need more power for passing or climbing a hill, just floor the gas pedal. This turns off the electrical power to the solenoid and briefly grounds out the ignition, which allows a spring to disengage overdrive. You are now back in direct drive. After you're done passing or are at the top of the hill, just release the gas momentarily and you're back in overdrive.
So the only time the car will free wheel is if the cable is pushed in and the car is going slower than 27 MPH.

[JLford]

Originally Posted by 40 Deluxe

By "depressed", I assume you mean pushed in. This position allows the overdrive to function but does not "engage" overdrive. Engagement is done electrically.
But let's begin with the car parked on your driveway with the engine off. Now pull out (rearward) the overdrive cable and go for a drive. The trans will operate just like a plain 3 speed standard transmission. The overdrive function is "locked out" completely. Next, push the cable in (toward the dash) and accelerate to about 20 MPH. Take your foot off the gas, and the engine will drop to idle while the car just coasts, or "free-wheels" because overdrive is not engaged yet. This is allowed by a sprag unit within the overdrive. The electrical part of the overdrive is off (or inactive) until turned on by the governor (usually at 27 MPH). Accelerate to about 30 MPH (or more) and let up on the gas momentarily. You will feel the overdrive engage, engine RPM will drop, and the car will no longer free wheel if you let off the gas.
Whenever you need more power for passing or climbing a hill, just floor the gas pedal. This turns off the electrical power to the solenoid and briefly grounds out the ignition, which allows a spring to disengage overdrive. You are now back in direct drive. After you're done passing or are at the top of the hill, just release the gas momentarily and you're back in overdrive.
So the only time the car will free wheel is if the cable is pushed in and the car is going slower than 27 MPH.

Ah, thank you for that explanation! Believe it or not I was treating the kickdown switch as the on/off switch for over drive, I had no idea it would engage automatically above ~27mph. Thanks again.

[rotorwrench]

Full freewheeling only happens at the low speeds below governor cut in. Above cut in speed it will still freewheel to a certain extent but not as easily as the lower rpm. It doesn't engine brake much until it is actually in overdrive but engine braking through the planetary is harder on it. The planet & sun gears are fairly small in the R10 overdrives. The later R11 overdrive is a lot tougher that the R10 since it has 4 planet gears instead of just 3. It will work well even with larger Ford FE blocks like the 352 and 390. Ford recommended locking out the overdrive when going up & down mountains or when towing anything heavy. This reduces the wear on the planetary set.

[Greg58]

Thanks everyone for the info, I'm sure there are others that can use this.