R10 and no reverse.....

[laynrubber]

Here I am again. Tried the search function and other than linkage issues, no answers.

So, R10, rebuilt by me. Had reverse engage a couple times but mostly not. Drove it last summer almost 2400 miles, the gear box and overdrive work smooth like a good dark smooth rum. I know that for reverse to engage the OD has to be disengaged.....I have the cable undone and the lever wired to a hard stop in the disengage position. I had linkage undone and checked to see if the shift arm on the side of the gear box is moving far enough....all that checks out ok. Yet, still there is no reverse engagement. 
What am I missing ? Am I splitting the gear box open for something in there ? I’m needing ideas. Pushing the car back has become tiring and embarrassing.

[Ulu]

It's like its not falling out of OD when the RPM comes down?

The speed governor is maybe stuck closed or binding.

I rebuilt mine in 1986, so tough to recall how it's shimmed, but be sure it's smooth.

I took mine all apart by bending the tabs.

Where does your speed governor wire go?

Just a switch? Or do you have kickdown setup?

[laynrubber]

Thanks for the reply. If I recall I am not using the governor. I have a 12 volt system now and a George Asche wire harness so I control when it goes in and out. Maybe the governor doesn’t know that now : )

[DJ194950]

If your first gear engages smoothly then the first/reverse selector seems to be adjusted OK.

 

Remove the OD solenoid from the trans. Try shifting into reverse with it off. If it works then your having problems with the solenoid or the OD shifter prall. It does block the shaft for reverse from moving when the OD is engaged.

 

My R-10 OD trans is also wired so that a button is pushed to operate a locking type relay so it is in or out.

Several times I could not get into reverse gear then I looked and saw the OD engaged light was on. Turned off the OD then I had reverse again- Simply amazing!

 

Just a thought.

 

DJ

[kencombs]

6 hours ago, laynrubber said:

Thanks for the reply. If I recall I am not using the governor. I have a 12 volt system now and a George Asche wire harness so I control when it goes in and out. Maybe the governor doesn’t know that now : )

Need to clarify what parts are in use and the wiring setup.  Without the governor, one would have to manually shift in/out with every move to higher/lower speed.  If left 'in' then there would be not reverse, IF I remember the workings correctly.

[Ulu]

If reverse is locked out by the OD, the car will typically freewheel. No compression braking happens.

 

The wiring can be done many ways.

If that harness isn't designed for the OD trans, there will be about 6 wires missing that work the OD and ignition cutout.

It's supposed to shift up and down like a 2-speed auto, when you work the gas pedal.

(The cable is to lock it off physically, so you don't freewheel, and run burn up the brakes going downhill.)

 

So, when you lift your foot off the gas, the OD should kick up when you're above governor speed (about 22mph on my old speedo.)

When you mash the gas while in OD, there's a switch attached to the carb or throttle linkage that kills the ignition for one beat.

When the gears unload, it slips out of OD, reconnects the ignition, and you've done a kickdown just like any slushbox, but faster.

 

This confuses folks, because the source of your primary coil voltage re-routs! When the OD toggle switch is on, the speed governor provides the ground for the solenoid, when above 22 mph, so the OD can kick up otherwise the solenoid doesn't move. Extra contacts in the OD solenoid click when it moves. Ignition voltage comes from either that solenoid thru the kickdown switch on the linkage, or directly from the key switch, when the toggle is off.

 

I never had a factory kickdown switch. I added a cheap sliding switch from Radio Shack on the firewall behind the carb, and drilled a little hole in the slider. I used a wire rod to run the switch from a lug I made, under the jamb nut of the carb linkage. There was a spring that returned the switch when you let off the gas a bit, and then the OD would kick up. The rod slid thru my home made lug and had a barrel clamp on the rod (from a VW accelerator cable?) so I could adjust the physical position where the linkage would pull the switch. As soon as you mash the gas, it pulls the switch radio shack switch, cutting the ignition (6volts) running thru it. Instantly, the solenoid slips loose, and clicks it's internal switch at the same time, restoring ignition voltage in only 1/3 revolution.

 

Is this making sense? It's been over 30 years since I wired that. Anyhow I added a short wiring loom from the new sliding switch, OD switch, OD solenoid, internal solenoid ignition switch, and key.

 

I also ran the governor wire which grounds the OD solenoid thru a momentary open push-button inside my shifter knob. This allowed me to prevent the OD from kicking up, if I wasn't ready for OD gear. Say it was wound up in second, and I was reaching for 3rd. I'm way over 22 mph, but press the button with the shifter hand, so it doesn't shift to OD as I'm slacking the gas to shift to third. In third, I can release the button, and it stays there until I lift the gas, finally kicking it up into 3rd + OD.

 

Now around town with 40- 45 mph speed limit, I could easily start the car off in 2nd gear, then never put it in third. I would work it like a powerglide until I hit the highway, then finally shift to 3rd. This eliminated 75% of my shifting in town, and I never hit the clutch unless I had to take off from neutral. I would slip the shifter to neutral as I was slowing to zero without the clutch. I would shift to 2nd (1st if going up a hill) and once in 2nd + OD, it was unnecessary to touch the clutch except from a dead stop, and I could slip it easily from 2nd to 3rd without clutch at 40-50 mph, with just a feather of the gas pedal.

 

BUT, the car was much faster off the line in a drag race with the worn out non-OD transmission, than the nice OD trans. Those extra parts add lots of weight and fluid friction in the trans. You're pushing more bearings and more parts thru the oil.

 

Otherwise it was a joy and I didn't even have to change the drive shaft.

 

[T120]

Ulu, Good explanation of the overdrive operation.I've found the following diagrams helpful.While they are in my Ford overdrive manual,the operation is the same as Chrysler. Also the video on youtube -" Chrysler Master Tech - 1952, Volume 5-6 Automotive Overdrive Controls"...☺️

[laynrubber]

Thanks for all the discussion here, I am not able to get to garage and check some stuff yet but Ulu here is the wire diagram for my set up .....

https://i.imgur.com/yNkusAy.jpg?1

I had the no reverse issue when I was running 6 volt and a 6 volt solenoid too. With the 12 volt solenoid I still have no reverse But I will try it with the solenoid removed. Otherwise this whole system works real well, shifts smooth.

[martybose]

If it is a complete R10 transmission the electrical system is irrelevant, as the shaft that the reverse shifter fork is on extends into the OD unit and mechanically locks out the overdrive, guaranteeing that no freewheeling can occur.

 

Marty

[9 foot box]

   The horizontal shaft that goes back has detents in it, for spring loaded balls, to index it. That shaft isn’t going back far enough to go into detent position. The control rod linkage is too long or the fitting or plug where the back-up light switch goes, is stopping it from fully engaging. The fitting can’t go beyond the bore of the shaft. The shaft has got to go past the hole to engage the back-up sender.