Overdrive keeps locking me out of reverse

JasonNC

I have the overdrive in my 48 working extremely well except for one thing. Sometimes after I drive it extensively, it won't let me go into reverse. It's rare that it happens and so far, both times that it happened I had just parked it my driveway. I am thinking that the car is still in overdrive when I switch off the engine for some reason. I am thinking that if I bypass the lockout switch by running the wire from the kickdown switch straight to the governor switch, it would eliminate the problem. Any ideas as to whether this will work or not?

MikeWA

I think your method would let you go into reverse while still in overdrive, which will destroy your overdrive unit as soon as you let out the clutch. I don't think you want to "work around" the reverse lockout- its there to keep you from having a catastrophe.

SuperDave

What is happening? The shift lever won't go into reverse? or is it going there, but the car is in neutral? if it's the latter.. That is normal for the single lever transmission. The Hudson shop manual says to pull the OD knob out if you want to go into reverse. I have had three different 49 cars and all were like that. Sometimes it works but most times it doesn't Sometimes I have held the shifter up in reverse and it might work.. My fathers 51 Super 6 was that way back in 1951..

bob ward

Its mentioned on here from time to time that running an OD in reverse causes damage to the OD. What are the mechanics of that, what actually gets damaged?

Geoff

MY '53 Hornet, which has single lever transmission and o/d does the same thing. I have to pull the o'd control out for reverse to engage. The gear shift lever does actually go into the reverse position, but the transmission remains in neutral. My Jet has the two-lever unit and this does engage reverse with the o/d control pushed in, so it's something to do with the engagement mechanism. Easier to just pull the control out than try and fix it!

Geoff

Bob, as to your question, it's to do free-wheeling mechanism. Too complicated to explain, but the transmission would be wanting to go in both directions at once, and hence most likely destroy something.

JasonNC

Super Dave, the shift lever won't go into reverse. The last time it did this, I jacked it up, tightened up the wires to the kickdown switch and the o/d and it started working again. We'll do it again tomorrow and see what happens.

[Deleted User]

My 49 Did that once and it was caused by the solenoid mounting bolt coming loose.
Roger

JasonNC

Upon further inspection, I'm beginning to wonder if I have a linkage problem as opposed to a lockout switch problem. There appears to be a lot of "slop" where the gear rod connects to the rod going to the transmission (just below the steering gear box). If that's the problem, what's the cure?

JasonNC

Where do you get those Ken?

Clutchguy

The problem is probably the overdrive is still in. This can only be a failing part. If it works sometimes and then not other times??,check the solenoid for proper operation. I have found when these start to fail-[go bad]-they will stay engaged. This doesn't necessarily mean the solenoid is the problem,but past experience usually points to this. Another question,is it converted to 12V ?. The governor can also cause this problem,but usually when it goes bad, it won't make contact and thus the O/dr. does not work at all. Remember, if the overdrive does stay engaged,the car will NOT back up,so don't pull in somewhere and not be able to get out. The best way to check the operation and diagnose this concern is on a level surface and the rear wheels off the ground with jacks stands placed properly. Once it occurs,pull it in,jack it up,try and remove the solenoid. If you here a click-dis-engaging-verify the overdrive cable will pull out. If it does,it can be the relay that was telling it to stay engaged-even with the key off,depends on how it is wired,or as said before,the solenoid is starting to fail. These are just some basic things to check before getting to much farther into it. Hope this helps, CG

JasonNC

THe overdrive cable will not pull out. It's stuck pretty good. The solenoid came out without having to be turned to the side and it looks like the solenoid seal has gone bad as oil is leaking out of the #4 terminal hole. The car is up on jack stands and I can turn the wheels forward or backward with the transmission in neutral. The car has been converted to 12 volts and the governor is working as I have an indicator light that lets me know when the governor has kicked in around 18 mph. I'm thinking the overdrive shift rail is stuck, but have no idea how to remedy any of my problems. I do have a spare solenoid that was working before I replaced it with the one that's now leaking oil.

Park_W

If the solenoid could be removed without turning it, that's likely the problem. If you installed the replacement one so that you can't pull it straight out, I'll bet your problem has disappeared.

50C8DAN

My 50C8 does the same thing. Most of the old timers told me that would be the case and it is.

lostmind

I had two 49's with overdrive , single lever. Never had to take it out of Overdrive to go into reverse.

Park_W

Doc, that problem is usually from a weak detent spring on the low-reverse shift rail in the transmission. With the OD "enabled" (button pushed in), there's a pretty strong spring in the OD unit that has to be overcome to put the tranny in reverse, and often the shift-rail detent spring isn't strong enough to hold the shift rail in reverse. This detent spring has to be much stronger on a tranny with OD, and sometimes it's been replaced with the weaker spring intendeded for a non-OD tranny. With the OD button pulled out (OD locked out), the strong spring in the OD is already compressed, so the shift rail spring doesn't have to overcome it, so it stays in reverse OK. The heavier shift-rail springs are getting a bit hard to find. Al Saffrahn had some made a few years ago, so may still have some.

JasonNC

The lever that O/D switch attaches to is stuck. Should I take the control switch off to see if I can get the slide to move? I keep fighting the urge to smack it hard with a hammer to get it to move forward. In addition, I noticed that the pin on the solenoid is extended and doesn't push in as if it's stuck on being energized. I thought it would go back in once the power to it was cut off. I tried to push it in, but it's not going in easily. Thanks for any help.

[Deleted User]

You say it was running on 12 volts . If that is a 6 volt solenoid it may have burnt up. There is no rhyme or reason to why some run for years on 12 volts and some wont.
Roger

JasonNC

I just went back to garage, forced the pin back on the solenoid, put it back on the transmission after making sure it turned a quarter turn and the pin wouldn't come straight out. The slide is now moving smoothly and I can put the car in reverse. Problems solved. I guess I'm a genius, huh?

MikeWA

Great that you got it fixed.

As the line in the old Beatles song goes, "I get by, with a little help from my friends. . ."

[Deleted User]

So the solenoid is bad having been stuck or is it free now ?
Roger

JasonNC

It was free when I took it off. It was full of transmission oil as it was the solenoid that I put the seal on backward. It was the spare and I put it on to see if it would work. I opened it and the other solenoid up and in both the points were jammed up at an angle (if you can figure out what I mean). In order to try and figure out what was happening, when I pushed the pin into too far, the points would separate, and then would lean up against each other and not come back down when the pin was released. I would have to lift the top pin slightly to allow the bottom one to drop down. I have no idea if this is what happened while the solenoid was on the transmission, but it could explain why the car is not dropping out of overdrive.