i have a 3 speed overdrive (stock) in my 51 merc that is not hooked up.i have converted to 12 volt system.. will this mess up the solenoid seeing as how it was a 6volt system? and how do you actually get into overdrive??? thanx for any input
I'm sure you can swap to a 12V solenoid but I'll bet there is a relay that needs to be changed too. If you can't find a 12V solenoid, your solenoid can be rebuilt and changed over to 12V in the process. My understanding is that along with the voltage differences, there may also be a difference in length of the shaft that inserts into your trans. I did a google search a while back and found a ton of related information.
A lot of guys run their 6V overdrive components on 12 volts with no problem. As far as how to get into overdrive, do a search, there's a ton of information here.
To shift into overdrive the overdrive handle must be pushed in toward the dash. Then when above 35 - 40 mph lift your foot from the gas pedal. If everthing is working well it should shift into overdrive regardless of which forward gear you are in. The weak spots in the system are the solenoid and the relay fuse on the firewall (driver's side). I can remember 50+ years ago having to buy new solenoids from the Ford dealer for $18. The salvage yards had plenty of used solenoids to sell but more often than not they would not work. I also learned that you could roll the relay fuse in a piece of aluminum foil and it would work well. I've owned several of these overdrives and in every case if you locked out the overdrive with the handle, when you were above the shift point speed the ammeter would drop slightly showing a discharge and the headlights would dim because the solenoid was trying to shift. You need to let it shift. It's OK to push the handle in while rolling, but don't try to pull it out unless at a full stop.
Might try comparing the solenoid with one from a '56 or later Ford. I'm kind of thinking they were mostly all Borg-Warner. Also have a governor wired in the system.
You need a 12V solenoid. I have seen 6V ones burn out on higher voltage. Also, you don't really need all the extra wiring that goes with the overdrive. You need a good solenoid and an on/off switch capable of several amps (I like 10 amps). The solenoid has two wires. Only one turns the solenoid on. Ground the solenoid body and give voltage to each wire. The one that kicks the solenoid on is the one you care about (it will kick, be careful). Run a wire from the on or accessory post of your ignition switch to the on/off switch. Run another wire from the on/off switch to the wire you care about on the solenoid. Your overdrive is now wired. To drive with this setup is easy: To get into overdrive while driving forward in any gear - push the overdrive handle in, turn the switch on, and let off the gas. The transmission will drop into overdrive if the engine can drop 30% of its r.p.m. To get out of overdrive while driving forward - turn the switch off, let off the gas lightly, and gently push back down on the gas. The transmission will drop back into direct drive. I have converted 4 old Fords to this overdrive setup. I prefer to choose when the transmission goes into overdrive instead of having the governor decide for me. On my 53 sedan I got a push on / push off switch from Radio Shack, gutted the element out of my lighter, and put the switch back there. I simply push in on the lighter to turn on or turn off the overdrive.
On my '51 Merc. I used a Borg Warner solenoid from a '56 Ford I believe. I then hid a Radio Shack relay in the stock relay casing. I referenced the 12 volt conversion book by Randy Rundle and there was a thread on here for the relay conversion. It all worked out well. I got most of my wiring from Mac's. They have the OD harness. Rundle sells solenoids I believe Posted using the Full Custom H.A.M.B. App!
when getting out of overdrive, take foot off gas, i pull the overdrive switch back out and shut off toggle.. is that correct
I paid $100 for a new 6v solenoid, but I got a used 12v one with a complete OD transmission for $50, and another one for $100. I have the kickdown switch wired to kill the ignition for a microsecond, so you can kick it down just by stomping the gas. In town I start in second gear, Lift my foot at 25 mp,h & it kicks up to second OD which is good for 50+ MPH. Basically it's an automatic until you have to stop dead & then you must push the clutch. ALSO: You can just gut a burnt solenoid & attach the end of a choke cable to the engagement pin. Then run the OD manually. I did this for a while until I got the right solenoid for mine.
Well, you really don't need to. I just leave the cable in and run the overdrive automatically. It goes on & off as it needs to. The only other thing I did was to put a momentary-open switch on the shift knob which breaks the solenoid voltage from the flyweight governor to the solenoid. Sometimes you do not want it to kick up at 25, but you don't want to hold the gas pedal down either, so you press the button. That prevents the OD from kicking up until you release it, say if you're climbing a hill at moderate speed and don't want OD. You can push the cable in, but the you have to stop the car to pull it back out. This way you just touch the button and release it when you're ready to kick up.
never pull the cable handle marked "overdrive" out when the vehicle is moving. serious damage can and will occur.
ok pardon my ignorance.. but if im in 3rd gear i push od lever in take foot off gas, it goes into overdrive.. now if im goin up a hill and loose power do i just down shift into 2nd to get rpms up or is that what the switch under the accelerator does? thanks for all the input you guys are helpin alot!!
The kickdown switch runs off the gas pedal. If the wiring is all good, you just stomp the pedal and it kicks down just like a 2-speed powerglide.
there is a guy in Kansas that sells 12v parts. http://www.fifthaveinternetgarage.com/tech_tips/tech_tips_upgrading_borgwarner_ODto12volt.html they sell manuals on how to do the conversion and are very knowledgeable. the solenoid needs to be grounded to activate the overdrive. I set up a 51 Mercury one time by disconnecting the power wire from the back of the cigar lighter and wiring it to the relay. By pushing in on the lighter element, it grounded and did the trick. No need to use a switch and incognito
The overdrive system is designed to be automatic. Think of the dash lever as a disabler. Under normal use the lever should always be enabled, only use the lever when you want to disable the overdrive. When working properly, it will upshift over 23 mph just by relaxing pressure on the gas pedal, just like an auto trans. When slowing down it will downshift at about 26 mph. With OD enabled, you will freewheel at speeds less than 23 mph meaning you will feel no compression braking from the engine. I like to have it upshift into second-over (by accelerating and then relaxing the throttle) and then I manually shift to third-over at highway speeds. The kickdown switch does two things: it kills the ignition and it interrupts power to the solenoid, so despite the fact that you want to go faster it momentarily kills your engine. The reason for this is to put slack in the driveline so the OD will downshift. I've been driving with my kickdown disconnected for years. I just downshift into second-over for passing and hill climbs. The gear ratios of Third-under and second-over are nearly the same anyway.
This is very accurate information, ^^^^. Here are my additions. Think of your transmission as two transmissions...you pull out your in dash overdrive cable and you have a straight three speed, nothing more, NO capacity for overdrive. As others have said DO NOT engage on the fly. Your second, overdrive transmission has a governor which engages contact somewhere around 30mph. Here I say around 30 mph because my governor and maybe yours can be adjusted up and down 5-10 mph. IF you have screw holes on the top and top side of the governor yours is adjustable. The other factor of course is your differential/wheel diameter combination, that's why in five post above we have 5 different results for when the governor enables the transmission to go into OD. I have mine set up without the kickdown , I wired a switch in line with a dash light to tell me when the transmission is in overdrive. http://www.oldcarmanualproject.com/...ner Overdrive/pages/Overdrive_Page_03_jpg.htm http://speedprint.com/deves50/overdriveindex.php Print these off and read it like the Bible. We're all in the same church but sitting in different pews...The Borg-Warner OD is the church, the front end transmission is the pew...Ford, Chevy, Dodge, etc. You dig? Keep asking questions, now , with the above info you'll know as much as any of us. Regards, Cosmo in the '49 running the 3sp+od for 15 years daily driver only vehicle.
Which is why that lever/knob exists. You WANT to disable the overdrive when driving on steep hills, so you don't lose compression braking and have a runaway. The internals of my Borg-Warner '49 Plymouth OD and my '59 Ford OD are virtually identical, except the shaft lengths and outboard splines. The governor and solenoid are the same, except the '49 is 6-volt.
IF it kicks up. What if the governor sticks and it doesn't? What if the solenoid sticks? What if the kickdown switch sticks? That knob is there for a good reason.
A lot of "new" overdrive owners, and some "old" owners don't really understand how the overdrive actually drives. It's simple to operate and kind of fun to drive and have the unique "skill" of knowing the operation. I made this driving video to make it a little easier to see how to drive with overdrive. Ford, Mercury, Chevrolet, Hudson, Packard, Chrysler (Plymouth, Dodge, Desoto) and Studebaker all operate like this. Some old Studebakers had a "cut-in" speed of 55mph, but still operate the same. Unless I'm driving in town with steep hills, I leave the overdrive cable/knob in or engaged. DO NOT pull the cable/knob out when moving.
I'm one of the 'old overdrive' owner/drivers. Your film is a prime example why I didn't want the kick down feature but set up a switch to turn the electrical connection on/off whenever I pleased. You have what I hear as 'lugging' when you go from 2nd over to 3rd over. I live in the piedmont region, lots of hills and that immediate shift from 2nd over to 3rd over just isn't going to cut it. You'll say "That's what the floor it into kick down is for". Exactly, I don't care for the surge of fuel to a kick down in gears. I had a previous transmission w/o use of a governor and split the gears to 6 forward, one under, one overdrive, 2nd under, 2nd od, 3rd under, 3rd od. It was a blast and I actually used one over quite a bit. I now have a '69 Saginaw/B-W 3sp+od with the governor. I did this so others could drive my truck w/o being so confused (by watching me shift). BTW, dd, only vehicle for 17 years, 15 with these great overdrives. Regards, Cosmo
Nothing wrong with your "switch" set-up, especially since you understand the overdrive very well. I made the video so new overdrive owners would see how it was designed to be operated, after all it's getting to be a lost art knowing how to drive them. "Old Pro Hot Rodders" will always find a way to improve old designs. My improvement was using 3.55 rear gears instead of 4.11 gears to make my (1780 lb) Model A with a stock flathead run at 75mph on the interstate, since highway cruising speeds have increased in the last 65 years and it's hard on them old flatheads running them at high rpm. Flatheads don't have the same HP and rpm curve as a small block Chevy or Ford V8, so I don't wind it up from second OD to third OD and the result is a second or two of slight lugging due to the taller gearing. Since my car is very light, compared to a 49-50 Merc, I jumped up to the 3.55 gears instead of a 3.70 set and I live in flatter country. I'm only on my 11th OD car and I have a couple of the 66-69 Saginaws under the bench, along with a good stash of solenoids and parts. How about you doing a video of how the switch set-up is operated? overspray
I thought your little video was first rate. Overspray, does one of your Saginaws have the adjustable governor? Mine does, it has 2 different settings. During my rebuild of my '69 Sag I opened up the governor and lo and behold the little bakelite spindle was broken into 10 little pieces. My machinist buddy made me one on his lathe in 10 minutes using a small piece of Micarta. Works like a charm, luckily there was enough mass to make accurate measurements for the new.
This is why I added the inhibitor switch to my shift knob. If I might lug I can touch it as I shift, & that puts the OD off for a couple seconds, before releasing the button and letting it kick back up.
awesome.. so when you say second-over,,its in second gear and the overdrive is engaged.then on highway manually shift into third and third-over is when overdrive is engaged..thanks again hamb guys are great!!!
Yes. It upshifts in second which is great for driving around town. Once you get going it's like an automatic transmission between second-under and second-over. It upshifts with a little throttle finesse and downshifts while coasting. Want more speed? You just manually shift to third-over from second-over. If you need to pass or hillclimb you can either manually downshift to second-over or you can nail the throttle and kickdown to third-under. Another interesting feature is that you do not need to use the clutch when shifting to second or third in underdrive. So you use the clutch to start in first, then clutchless shift to second, automatic shift to second-over, slow down automatic downshift to second, slower clutchless shift to neutral, stop. You just drove from stoplight to stoplight up to 50mph and only touched the clutch pedal once! You can actually get it shift into first-over, but that takes some serious revs and serves no practical purpose.
As shown above, there are many ways to set up the controls. I guess the difference in preference is how much you like automatic operation and how much you like additional parts that can cause trouble. I like things as simple as possible and don't like automatic operation if I can choose when things happen. That said, the stock setup is very reliable if it is all in good shape. I once sold a 50 Ford that had my minimalist overdrive control setup in it. The next owner was very proud that he added all the controls. Around the same time I bought a 66 F-100 with factory overdrive and bypassed all the factory electrical controls. Preference really. Maybe... The engine has to drop rpm by 30% for overdrive to engage. If your car is running away (driveshaft spinning faster that the ring gear in the overdrive planetary gear set), you have to nail the gas until the engine is pulling the car, then let off the gas to drop into overdrive. If you do this, you have accelerated down hill, then dropped into the worst gear ratio for compression braking.
The Jalopy Journal
