Overdrive frustrations

[Ernie Baily]

Hello everyone,

I am still having problems with the engaging of my overdrive(53 ply overdrive trans in 48 Ply). I have replaced the wiring, solenoid, rebuilt the governor, put new relay on, flushed the trans and overdrive and put new gear oil in. However it engages intermittinly. Is their a shop or person that I can take it too? I'm at wits end! I live in Simi Valley, Ca(Ventura County/Los Angeles area).

Thanks,

Ernie Baily

ernestbaily@att.net

 

[martybose]

The only thing I see missing from your list is the interrupter switch on the bottom of the transmission; did you replace it?  Just be aware that if you take it out while in the car there is a little metal plunger that will fall out when you pull out the switch which is an absolute bear to get back in.  There is a special automatic transmission assembly grease that is used to hold check valve balls in valve bodies that you can use to hold it in place while you get the switch installed.

Have you checked to make sure that you have full travel on the cable to the shifter?  I had a problem there until I changed the cable routing and secured it better.

Marty

Edited November 18, 2017 by martybose
Added another possibility

[Ernie Baily]

Hi,

If you are referring to the "Lockout Rail Switch" the answer is no. I currently have a bypass wire between the two connections. I also replaced the kickdown switch too!

[55 Fargo]

Contact timkingsbury he and or George Asche can help you out experts on these tramsmissions...

[JOHN EDGE]

The system is fairly simple and if it's working sometimes then eliminate any controls other than the ones that engage the solenoid .  The governor grounds the relay and current flows thru the relay to operate the solenoid.  You can static check the relay by grounding the governor wire and then checking for current at the solenoid I can hear my relay click when driving. Make a jumper wire and test drive it I eliminated all the external controls (ignition cut off, passing cut off) unless you have a mechanical problem within the overdrive but I doubt it. I had the same problems til I rewired the overdrive unit

[knuckleharley]

I doan no nuttin bout no overdrive,but since it works sometimes and doesn't work other times,the first thing I would look at would be the grounds to make sure they were clean and tight/

[dpollo]

If the engine rpms do not fall off fast enough then the overdrive will not engage.  or if the idle speed is too fast.

The balk or blocker ring in the od unit prevents engagement. 

This is an intermittent situation depending on several factors so this may explain the sometimes or sometimes not behaviour.

[JOHN EDGE]

6 hours ago, knuckleharley said:

I doan no nuttin bout no overdrive,but since it works sometimes and doesn't work other times,the first thing I would look at would be the grounds to make sure they were clean and tight/

 

6 hours ago, knuckleharley said:

I doan no nuttin bout no overdrive,but since it works sometimes and doesn't work other times,the first thing I would look at would be the grounds to make sure they were clean and tight/

You must be that guy from the old AAMCO commercials "I always wanted to be a transmission mechanic"

[Ernie Baily]

Hi everyone,

I've done the tests many times, checked my wiring too! The next thing is to go back thru the wiring and sodder all the wire connections(I used crimped ends) and check grounds. I currently have the Idle set a 750 rpm( to keep generator charging at Idle speed). The book calls for the idle to be between 450-475 rpms. I'll give a call to George Asche to get some advice, I think I have a phone number in my Overdrive info I have collected.

I took it out for a drive the other day, the car works so good, a consistant working overdrive would be the iceing on the cake!

Thanks for all the comments!

[dpollo]

That high an idle speed is at the root of your problem.  RPMs must drop off 30 % and do it quickly or the internals of the overdrive will not allow it to engage.

    The generator need not be charging at idle.

[Ernie Baily]

OK, I reset the idle to 450 rpms at Idle. I took it for test drive and it did shift into overdrive only once. Should I get a stronger throttle return spring?

Still frustrating!

[JOHN EDGE]

All you have to do is crack the throttle once you've exceeded approx 35 mph and allow the engine to release the torque applied to the driveline and the  solenoid will apply the overdrive. The engine is not going to return to idle unless you push in the clutch. That doesn't need to be done. Just a momentary throttle release

[Thomba48]

To me the following link leads to a perfect description of how the OD works.

http://www.fordification.com/tech/overdrive.htm

Sorry for the "ford" in the name link :-)

[Don Coatney]

1 hour ago, Thomba48 said:

To me the following link leads to a perfect description of how the OD works.

http://www.fordification.com/tech/overdrive.htm

Sorry for the "ford" in the name link :-)

Great link, thanks for sharing!

[plyroadking]

On 11/18/2017 at 10:25 AM, Ernie Baily said:

Hi,

If you are referring to the "Lockout Rail Switch" the answer is no. I currently have a bypass wire between the two connections. I also replaced the kickdown switch too!

How's the rest of it wired? Did you follow a factory diagram? If your wired like it's intended to be it's electrically trying to engage overdrive when you're driving around at +25-30mph with it mechanically disengaged. I never recommend bypassing the lockout switch. 

I troubleshoot mine by running a switched ground wire to the governor terminal on the lockout switch. When the rest is wired as intended, you can push the cable in, turn the key to the on position, and toggle your "gov overdrive" switch. You should hear both the relay and the solenoid click. 

 

[Ernie Baily]

Some where I read that the later models did not have a lockout switch, just bypass it if suspected a bad switch. I'll take out the bypass wire I made and see if that does any thing. I think I'm going to soder the wire ends on the wires going to the solonoid and govenor. I'll make up a "gov overdrive" switch and see if I get the relay and solenoid clicks.

 

Thanks Again!

Ernie

[dpollo]

Make sure the wire to the solenoid is at least #10.  The engagement current is significantly higher than the holding current.

Also, if possible draw the power for the overdrive from the starter solenoid terminal rather than through the ignition switch.  Some overdrive relays are set up to do this.

However, the overdrive circuit does not draw power below "cut in" speed, so it can be wired this way successfully.

Rail lock out switches were not considered necessary when 12 volt systems came to be because of lower amperages.

[Ernie Baily]

OK! ,  I'm back from my mini vacation trip. I took out my by-pass wire on the lockout switch, I then did a test drive and it engaged three times during the test drive. I currently have the wire #10 black wire going from the overdrive relay to the starter solenoid instead of going to the Ignition terminal on the horn relay(as in Plymouth service manual). I'm still planning on sodering the wire connections too!

Frustrations go on!

Thanks everyone for the tips and advice!

Ernie

[Ernie Baily]

OK, I sodered the wire connections and all looked good. Then I decided to disconnect the wires on the horn relay and clean it up and clean wire connections. I then started to reconnect the wires and forgot which wire went where(DAH!), after working with it all day, all is fine, starts and runs fine, horn works fine too!  But now when I attemp to hook up the overdrive(Black #10 wire from relay to Bat post on horn relay as shown in Service Manual) the relay/solenoid keeps clicking). I must have done something when I was fooling with the horn relay wiring! The only thing I can think of is that the points in ether the relay or solenoid  or both have fused together.

Any other advice?

[Ernie Baily]

Well, I did some further testing of both the new and old relays and found out the new one had a closed circuit and was causing the clicking every time I connected the Batt cable. I put the old one back one and it seems to work OK! I then took it for a test drive and would hear a clicking once in a while, so I pushed in the kickdown switch and that was the same click, so I believe the new kickdown switch is bad. I put in my old kickdown switch in and now no clicking. I have contacted George Asche several times and he now suggests to bypass the Governor circuit all together and use a ground switch to activate the solenoid at speed like the governor would normally do and see it shifts into overdrive. I hope to get this done later today.  We'll See!

[Ernie Baily]

Hello everyone,

Well, I did the test and still does not engage the overdrive. I checked the wiring and made sure all the wires are done like the diagrams in my Plymouth Service Manual. I'm starting to think it might a problem inside the trans. I bought the trans over 30 yrs ago(nothing lasts for ever). The other concern its the wiring I have for my petronix electronic ignition, it is different than the stock wiring diagram. Has anyone done a petronix on a 46-48 Ply other than Me?

 

[timkingsbury]

1 hour ago, Ernie Baily said:

Hello everyone,

Well, I did the test and still does not engage the overdrive. I checked the wiring and made sure all the wires are done like the diagrams in my Plymouth Service Manual. I'm starting to think it might a problem inside the trans. I bought the trans over 30 yrs ago(nothing lasts for ever). The other concern its the wiring I have for my petronix electronic ignition, it is different than the stock wiring diagram. Has anyone done a petronix on a 46-48 Ply other than Me?

 

 

Well here is the wiring diagram (courtesy of George Asche.  Yes bypassing the circuit certainly tells you whether that was an issue.  The electronic ignition by itself really doesnt have anything to do with anything assuming everything is wired correctly.   Ill drop you a pm.