Overdrive Works

[Joe Flanagan]

It seems I have a working overdrive. Since I've never driven a car with this kind of overdrive, I didn't know what to expect. I asked a few guys how I would know whether it was working and got some good pointers but the one that I really noticed was the absence of engine braking when cruising at highway speed. I did not hear any kind of click when the solenoid engaged (but then again, my hearing is shot). I also haven't really noticed the ammeter showing a discharge at the point of engagement. But after using the overdrive a few times, the thing I really notice is that when I'm going 50-60 and I let up on the accelerator, it feels like the car is being driven by itself. It's almost like someone else has their foot on the gas. I guess it would be funny in a perverse kind of way if my overdrive wasn't working at all and my accelerator linkage was getting stuck. But there's a definite difference between 60 MPH in conventional drive and 60 in overdrive. Again, my first experience with this, but that is what I notice.

I've been reading the Borg Warner manual and the Chrysler tech series to familiarize myself with what is actually happening inside the thing. If anyone has advice on what I should be looking for to make sure it's operating correctly, I'd appreciate it. Back when I installed it, I bench tested the relay and the solenoid and both worked, so I imagine they're working now, too. I saw on an old post a picture of some pinion gears that were all mangled because they didn't have enough lubrication, so I made sure both halves of the transmission were filled with oil. The weather is kind of unpredictable here in Virginia right now but if it holds up, I'm going to take another cruise on the highway with it. I've almost got 200 miles on the Plymouth now.  

Edited August 23, 2014 by Joe Flanagan

[plyroadking]

They are a very robust overdrive unit, my cautions would be to never pull the overdrive disengage cable while your moving, and remember to disengage the od when your parking the car somewhere, if you dont its like leaving it in neutral.

[pflaming]

Take a drive on a rolling / hilly road. Get to speed, let up and let the od engage as you are doing, then when pulling a hill when the engine begins to labor, push on the foot pedal and engage the OD, it's like shifting into a lower gear which is really what is happening. OD's make hilly roads level.

 

 When you are comfortable with the unit, then take 2nd gear to a high RPM, let up on the pedal and it will engage in 2nd as well. Very nice to use in slower traffic. OD's properly used, REDUCE shifting by a bunch.  ENJOY, I've got one to install as well. 

[Plymouthy Adams]

pflaming, on 23 Aug 2014 - 09:05 AM, said:pflaming, on 23 Aug 2014 - 09:05 AM, said:

Take a drive on a rolling / hilly road. Get to speed, let up and let the od engage as you are doing, then when pulling a hill when the engine begins to labor, push on the foot pedal and engage the OD, it's like shifting into a lower gear which is really what is happening. OD's make hilly roads level.

 

 When you are comfortable with the unit, then take 2nd gear to a high RPM, let up on the pedal and it will engage in 2nd as well. Very nice to use in slower traffic. OD's properly used, REDUCE shifting by a bunch.  ENJOY, I've got one to install as well. 

?  I see your splitting gears with hi/lo in each ..but you are putting it into OD will not level hills when engaged..is this a typo and dis-engage is what you mean..

Edited August 23, 2014 by Plymouthy Adams

[pflaming]

Possibly, haven't had my coffee yet.  What gets interesting is to load the car, five adults and drive the same hilly road, then work the OD in 2nd and high so that the rpms remain the same, that is, drive it like a truck. Works great with a trailer behind and a couple of salvaged Mopar 6's in it.

 

I will put a tach on my car/truck and somewhat drive by the tach. OD's are fun. You can even move the switch from the floor and control it by hand by putting a switch on the steering post. 

[1941Rick]

The overdrive is a must if you drive the highway.....

As for engine braking, I do notice braking while in OD. Not nearly as much as when out of OD. The only time I can get free wheeling is when the speed comes below 26 mph and the OD dis-engages.

2ND OD and 3RD direct are pretty much the same ratio. 

If you want more control over OD, you can get rid of the kick down switch and add another relay hooked up to a switch on the shift lever or dash. This will allow you to cut out power to the OD relay and shift out of OD. When the OD unit shifts out you can then pull the OD selector. Dont pull the selector out before OD dis-engages

[plyroadking]

The overdrive is a must if you drive the highway.....

As for engine braking, I do notice braking while in OD. Not nearly as much as when out of OD. The only time I can get free wheeling is when the speed comes below 26 mph and the OD dis-engages.

2ND OD and 3RD direct are pretty much the same ratio. 

If you want more control over OD, you can get rid of the kick down switch and add another relay hooked up to a switch on the shift lever or dash. This will allow you to cut out power to the OD relay and shift out of OD. When the OD unit shifts out you can then pull the OD selector. Dont pull the selector out before OD dis-engages

Or you can leave your kickdown switch and run a wire from the governor side of the lockout switch to a toggle switch on the dash, then run a wire from it to ground. You become the governor then and can still maintain the original functions.

[pflaming]

With this toggle switch setup, can you activate the OD at various speeds and in any gear? With the toggle switch on ON or OFF does the regular manner of operating via the gas pedal then become active again?

[1941Rick]

Or you can leave your kickdown switch and run a wire from the governor side of the lockout switch to a toggle switch on the dash, then run a wire from it to ground. You become the governor then and can still maintain the original functions.

You would only have to put the toggle in series. No need to ground. The gov is a grounding device. If you were to ground the toggle switch you would in fact be telling the od relay to operate.

[DJ194950]

Really 1st. gear OD I useless. 1st. is so low that the OD may add 5mph. before time to shift to 2nd.

The advantage of the toggle inline with the govenor ground is that when you want to drop out of OD, rather than having to put the throttle to the floor or push the OD handle in and letting off the gas you can just turn off the toggle and let off the gas= out of OD. Want OD again? flip the toggle to on and let off the throttle momentarily- Od will engage as long as you going more than the 26 mph. for the govenor to provide the ground to the relay.

 

Yes to Joe F. on the trans question. The OD will pretty much freewheel when in OD and you let off the throttle until the throttle is again pushed. Has to do with the OD clutch cam and the rollers. When the engine rpms drop slowing down or no longer puttting a push against the drive line the rollers back down the ramps in the clutch and lose contact with the out put drum and output shaft until you accelerate again. If OD is locked out the clutch is locked out and plays no role. Direct drive thru the OD section.

 

All this is only about an R-10 OD trans as I have no experience with the R-7.

 

DJ

[Dodgeb4ya]

When the OD transmission is actually in overdrive gear-over 25-28 MPH with the OD handle pushed in there will be NO free wheeling.... ever.

At 25 MPH and under with the OD handle pushed in and out of overdrive gear the car will free wheel when coasting or when accelerating and then letting off the gas and again coasting.

Same as Its normal for the car to always free wheel up to a OD kick in speed of approx. 25 MPPH with the handle pushed in.

[DJ194950]

Dodgeb4ya-

 

Maybe the question is- On mine the OD handle is pulled out before the OD works. In = no OD or freewheeling. The bracketry show the the cable and arm made it work that way. I believe. Did not come in this car.

 

Yours work the opposite? Is it an R-10 type?

 

DJ

Edited August 23, 2014 by DJ194950

[Dodgeb4ya]

All the 1952-54 factory MoPar OD cars.... The OD handle is pushed in to get the overdrive transmission to operate.

 

Never seen one operate the opposite as yours!?

[DJ194950]

Like I said it appeared because of where an original bracket and arm where on the od when I bought it. Not sure if it could be mounted the opposite or not, seems per a old memory that the floor board would have been too close for it to go the opposite way.

 

Had an OD the similar r-10 back in '68 in a 54 Ford. Worked OK after small amount of outside repair (governor weights) but don't remember if engaged was pull out or push in.

 

Joe F. which way does yours work?

 

DJ

[Dodgeb4ya]

It does not matter as you know whether the handle is in or out to make the OD engage.It works even though the lower cable and bracket is not in a stock position.

My above statement the handle must be in for the car to free wheel pertains to the factory OD Mopar setups.

I do not know much about anything on a 1946-54 Mopar that is not stock!

[greg g]

Joe, the term overdrive refers to the comparison of the 1 to 1 aspect of high gear, toone tat is 1 driveshaft rev ti .73 crank shaft revolution, hence the dive shaft being overdriven in comparoson to the engine. Generally it provides a 27% reduction of engine speed to road speed with the od engaged. Think of the lock up of the torque converter in a modern vehicle for a comperable "feel".

[Joe Flanagan]

Right, according to the Chrysler manual there is a roughly 30% increase in efficiency with the overdrive functioning. The example they give is the one to one ratio of third gear in conventional drive giving you 1000 rpms of the rear wheels with 1000 rpms of the engine. In overdrive that changes to 700 rpms of the engine giving you the same 1000 rpms at the rear wheels.

My overdrive works with the handle pushed in. I've never heard of it being the other way round. My kickdown switch is a points-normally-closed momentary switch mounted under the dash.

[steveplym]

Right, according to the Chrysler manual there is a roughly 30% increase in efficiency with the overdrive functioning. The example they give is the one to one ratio of third gear in conventional drive giving you 1000 rpms of the rear wheels with 1000 rpms of the engine. In overdrive that changes to 700 rpms of the engine giving you the same 1000 rpms at the rear wheels.

My overdrive works with the handle pushed in. I've never heard of it being the other way round. My kickdown switch is a points-normally-closed momentary switch mounted under the dash.

 

I've got the same momentary switch on mine.  Basically hooked up in the same place the kick down switch would be connected, just did not connect it to the ignition circuit as diagrammed.  When I need it out of od, for example slowing down behind another car, I let off the accelerator and hit the button.  Interrupts the circuit and kicks it out of od. 

 

Mine is set up cable in is od and cable out is conventional drive.  I've driven with this trans over 5,000 miles and no issues to date.

 

You can definitely feel the od kick in once up to speed in 3rd gear direct drive and you let off the accelerator.  Almost like having another gear.  You will enjoy the extra gas mileage too. 

[DJ194950]

Thanks for the In/out OD op. answers. Seems mine is working backasswards! Original parts? Dealer installed parts? Like I said before I have no idea, or if I just screwed it up! 

 

Always seemed to me that that the cable in should = the OD in. Logical always works best, But many things do not work according to my logic! 

 

Planning to take my car out to a friends with a 2 post lift and will get it up and take a look again. Maybe a different set of eyes may see what's up!

 

DJ

[Joe Flanagan]

It's funny, but I never feel the overdrive kick in. I also never hear anything like a click as I've heard others describe when the solenoid activates. When I'm in in 3rd gear direct drive and I get up to speed and let up on the gas, there is nothing that tells me the overdrive has engaged until I step on the gas again. Then the car just feels different. It feels like it's less responsive to the accelerator yet is kind of pushing itself along, almost like the power is coming from behind the vehicle. I can't say that mine is definitely quieter with the OD engaged. It might be somewhat quieter, I'm not sure. But I drive with all the windows open and the cowl vent open, so there's a lot of noise anyway. I've yet to test the accuracy of my speedo with a GPS. Today I passed one of those digital readout signs that say, "Your speed is XX MPH." It clocked me at 43 but my speedometer read 50. I've always suspected that my speedometer was reading a little high. My neighbor loaned me his GPS device and I will be checking it soon. 

[Young Ed]

Joe the best way would be to rig a tach up even its temperary.

[Joe Flanagan]

Yeah, I might do that. I just need to find a 6 volt tach, right?

[Young Ed]

Yeah, I might do that. I just need to find a 6 volt tach, right?

Joe you might be able to use a tach dwell tuneup meter. Dads is 12v and it still works. For your purposes even if the RPM isn't right as long as it shows a drop if/when the OD clicks in you'd be good.