BorgWarner Overdrive Questions
 

OK, I’ll be installing a BorgWarner overdrive in my ’51 Ford and I’ve got a few quick questions about it. I’ve read both the service manual and the reference book written by Randy Rundle, so I know roughly 98% about it, but I don’t recall seeing answers to these questions in either document. (Maybe I missed them?:confused:)

Question 1: When overdrive is engaged (at speeds north of 28 mph), it’s not a problem to downshift into second gear, is it? I ask this because there may be situations where you need more power than the wide-open-throttle kickdown to direct drive provides.

Question 2: To disengage overdrive, do you have to be completely stopped to pull the control handle out, or can you just press the clutch and do it while driving?

Question 3: This may be the toughest one to answer. Since my car has the conventional three-speed transmission, I assume it also has the standard 3.73 rear end (though I haven’t torn it down yet to confirm). I know overdrive-equipped models had a racier 4.10 ratio for better low-speed pick-up. How well will 3.73 gears work with overdrive? I don’t mind a car with long legs for relaxed highway cruising, I just don’t want them to be too long. For reference, the engine will be a mildly built flathead V8 tuned for torque. It will have a 4-inch crank, boosted compression, a mild overbore, an Isky 1007B cam, a stock intake and a reworked Chevy distributor, nothing crazy.

Thanks!

Re: BorgWarner Overdrive Questions
 

Do not pull that handle out with the car in motion. By do not I mean never. You can either disengage the overdrive with the kickdown switch which is difficult or come to a compete stop which is what I do. I hardly ever pull that lever out. Only if I have a lot of downhills. Uphills I kick out the OD with the gas.
I have the higher gears and I have crossed the rockies a few times as well as some other high mountains.
Shifting between gears up or down while the OD is engaged is not a problem. Sometimes I let the OD shift in second and then wind up before going to third.

Re: BorgWarner Overdrive Questions
 

Hi,
Maybe a sort of different animal but the 50 Plymouth I owned for 37 years had the org stock 6 cyl. I had switched to 3.55 gears then added overdrive. I was very pleased with it. I sure you will be fine with the 3.73 gears and extra stroke and tuning for torque.
Steve

Re: BorgWarner Overdrive Questions
 

I have owned lots of overdrives. You can shift the transmission with overdrive engaged just fine.

You can pull the handle out while driving. You need to be in direct drive and be accelerating when you pull it. If in overdrive just hit passing gear and pull the handle.

I ran a 'stock '50 Ford many years with overdrive and a 3.73 rear. Never any problems in hills or flat land.

Re: BorgWarner Overdrive Questions
 

I would never pull the handle out while driving. Not good . you can push it in to put the car in overdrive anytime. I also use a toggle to turn the o/d system on or off...allows you to "kick down" without flooring the throttle.....and times 2 on what Frank Miller said.
mike

Re: BorgWarner Overdrive Questions
 

A lot of folks may have apprehension about pushing the car into direct drive since it has be forced into the kick down on the throttle but it will not hurt the unit when done properly as 40cpe mentioned. The other alternative is to slow down to drop out speed then accelerate & pull or just pull it out at a stop. It's no big deal.

Pressing the clutch is not the way to go to lock out the overdrive. It has to be under drive with accelerating forward motion to lock it out.

My Mercury cars have a 3.92:1 ratio and they work OK. A lighter Ford car should work OK with a 3.78:1 ratio but it will be a taller gear and will affect the points you shift at. I think the reason that the Mercury & Ford cars used the higher numerical ratio was so that the car would function to start out from a stop in 2nd gear under a lot of flat land conditions. This way the drive would be semi-automatic for city driving at speeds from 30 to 40 MPH. A lower numerical ratio may not allow for that type of driving very well. It would certainly be OK for highway speeds though.

Re: BorgWarner Overdrive Questions
 

Page 6, Section Number 13, of the Borg Warner Overdrive Manual tells how to pull the OD handle out while moving.
http://www.oldwillysforum.com/forum/...riveManual.pdf

Re: BorgWarner Overdrive Questions
 

if you are in od. and do not want to floor it to passing gear just turn the key off and back on quick and you are out of od. been doing it for 75 years

Re: BorgWarner Overdrive Questions
 

Really 75 years? That said, your idea sounds like it would totally work. Unique approach.

Re: BorgWarner Overdrive Questions
 

Wrong! Post #4 is correct! I know from personal experience. Did just that often.

Re: BorgWarner Overdrive Questions
 

Nothing happens if you try to pull the handle out while in overdrive. It simply won't move. Hit the kickdown and simply pull it out while moving. See post#4 and others.

Re: BorgWarner Overdrive Questions
 

Wow! That is excellent information! Everybody that has an overdrive transmission needs to print this, read it and keep it handy. Thank you for sharing!
P.S. Note the lubrication warning in large print on the last page.

Re: BorgWarner Overdrive Questions
 

Glad I asked these questions, lots of great information in this thread. I like Chain Drive's idea of shutting the ignition off for a second to put it back into direct drive without having to floor the gas.

Re: BorgWarner Overdrive Questions
 

hi i meant to say i am on the other side of 75 had a 50 convt, with od. i learned to wreck them and learned to fix them one of the best inventions ever made i still have them in my cars

Re: BorgWarner Overdrive Questions
 

I also understand that the convertible X member frame required a different OD casting than the regular cars. Newc

Re: BorgWarner Overdrive Questions
 

48 and 50 convertibles require a mechanism to mount the solenoid below the transmission. Other than that they are all the same.

Re: BorgWarner Overdrive Questions
 

A person may experience an after fire now and then when turning the ignition key off while driving. A lot depends on how you work the throttle with the key off. A little too much throttle and she will talk to you in loud fashion.

Re: BorgWarner Overdrive Questions
 

What advice can I get regarding oil for my R10 overdrive? The repair manual recommends SAE 40 engine oil or straight SAE 80 mineral oil. Randy Rundle recommends non-synthetic 80/90 gear lubricants. I purchased a gallon of 80/90 GL-5 extreme pressure gear oil because that is all I could find locally but there seems to be some debate over whether GL-5 oil will destroy yellow metals. Some say that modern GL-5 is safe to use and won't hurt. I've hesitated in using this oil and wonder if I should return the oil to the store and try to find GL-4. Any wisdom to share? What are people using?

Re: BorgWarner Overdrive Questions
 

google "gl-5 yellow metal safe oil". There is lots of information. If your container doesn't say it's yellow metal safe I would not use it OR I would contact the manufacturer. It seems that some/most modern oils use a type sulfur that doesn't attack brass. But it is hard to get past old ideas. I'm not advocating GL-5 in the transmission, just passing internet information along.

Re: BorgWarner Overdrive Questions
 

I use SAE-50 grade 100 aircraft engine oil (AeroShell W100) with NO Lycoming additive. I could use the blue Swepco 201 SAE-90 that is used in the Robinson helicopter transmissions but the AeroShell W100 is less expensive and works fine for my 1951 Mercury cars.

SAE-50 motor oil is the same viscosity as SAE-90 gear oil due to the different way the two are graded.