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Was wondering what causes the car not to go into reverse when the car is in overdrive. This does not happen all the time.. If you take it out of overdrive all works fine.. I have had this problem on different Packards over the years..

Overdrives are not my strong suit and I know someone will come along with a better answer, but I believe that overdrives incorporate an overrunning (one way) clutch so that if you want to reverse direction, it must be inactivated. Hence the "reverse lockout circuit" on some of the earlier ODs, like the R-9 I believe.

Does the trans lever not go into reverse or does the car not move once there?


A sleeve in the OD has to move to lock two sections together to eliminate the overrunning clutch and is operated either by the lockout lever or by the reverse shifter in trans. That pushes a rod into OD case to move the sleeve. There are also some springs involved so that area would be one place to look.

It sounds as if either the sleeve is binding, springs may not be strong enough or the shifter rod is not moving enough. If the overrunning clutch can't lock out, things are moving internally the opposite direction needed to lock the clutch so effectively nothing will be connected to drive shaft.

When I converted my R11 to a floor shift for my 38 I had to add a tab to the 1st R shift fork to push a rod inside the tranny case(my tranny doesn't have an external lockout switch) and so far in 3 years I've never had any trouble going into reverse. The only odd thing that I've had happen is that sometimes if I shut off the car and leave it in gear it will roll away

If you lockout the od manually after use with the dash control you shouldn't have a problem with reverse. If not, you are depending on the plunger rod (from 1st/rev shifter fork)pushing on a spring that pushes the lockout collar fork. If the spring is weak or the lockout collar doesn't move freely due to a gummy buildup on collar you will have a problem. You can disconnect the od cable from the lever on the overdrive and try moving by hand to see if it moves freely. You might also try draining and refilling with fresh lubricant.

To diagnose the problem there are 3hree questions that need to be answered first:

1. HH56's questionfrom above:
"Does the trans lever not go into reverse or does the car not move once there? "

2. What kind of over drive is it????

3.Does the over drive have a built-in freewheeling feature???

Or perhaps a better question is:
Why would anyone ever want to operate in reverse overdrive rather than just reverse no overdrive engaged???

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If all is working correctly OD will always be disengaged whenever you go into reverse.

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If the dash od cable knob is pushed in you will be in "freewheeling" mode. If when parked you leave knob in and the transmission selector in any forward gear the car can roll. If you put it in reverse (with the cable knob in) you will have a direct connection to the engine and the freewheeling is locked out (with properly working internal plunger). Probably best to lockout od manually with cable pulled out when parking.

Thanks for all the help. To answer some of the questions, The overdrive is a R11 which came in my 53 from the factory. When using overdrive and have to back up, the car acts like it is in neutral. If I disengage the overdrive the car works fine and backs up. Again this does happen all the time. Hope this help answers some of the questions...

It sounds like the sleeve or gear lockout mechanism is sticking but there could be a couple of reasons. Since it works when you do it manually I'd lean toward gummed up or a weak spring. I would start with JT120's suggestion of checking the motion to make sure that it feels smooth and nothing catches. If the oil is too thick or the mechanicals have gummed up, then a drain & refill with the proper weight oil might work but it also might need to be cleaned a bit more thoroughly.