727 won't go into park. B/U, neutral switch?

[Dustyrides]

Just changed the (3 prong) light switch in my 68 727 because it was leaking and now it acts like it isn't fully engaging into park position. It runs fine in neutral but whenever I put it in park, it makes the sound like when you shift into park when the car is still rolling. Like a deep ratchet noise and shuts off. Was fine before changing the switch. Unfortunately the one I replaced got thrown away so I can't compare. I'm thinking that the new switch is preventing the shifting arm from fully engaging in park. I don't want to try a different switch until I know what I'm looking for. And the new switch leaks through the pins so I definitely still need a good switch.
Thanks for reading!

 

[dvw]

Loosen the switch a turn or so. If it goes into park the switch is the issue.
Doug

 

[turbine68rt]

68 uses the single pole switch. Did you have a 69-up style switch in it prior to changing it?

 

[Dustyrides]

68 uses the single pole switch. Did you have a 69-up style switch in it prior to changing it?

I replaced what was there. I don't think the transmission is the original.

 

[Dustyrides]

Loosen the switch a turn or so. If it goes into park the switch is the issue.
Doug

I was afraid it would leak, but that could prove the issue.

 

[turbine68rt]

I replaced what was there. I don't think the transmission is the original.

Did you determine it was a 68 by the date code?

 

[Dipstick]

68 uses the single pole switch. Did you have a 69-up style switch in it prior to changing it?

Changeover to 3-prong was mid-year '68. Some aftermarket switches are known to be too long.

 

[turbine68rt]

I have my original 4/68 trans. Still single pole.

 

[dvw]

I was afraid it would leak, but that could prove the issue.

It will, but not a lot.
Doug

 

[Dipstick]

I have my original 4/68 trans. Still single pole.

May 15 was the approximate changeover date.

 

[turbine68rt]

May 15th is rather late in the production year.

 

[Dustyrides]

Did you determine it was a 68 by the date code?

The stamped numbers the best I can tell are: PK2392090L 2362 8159. I Don't see any numbers that resemble a date.

 

[turbine68rt]

January 15, '68 assembly going by the 2362 date code. Valve body may have been changed at some point.

 

[T Brashears]

If it was ok before,get another switch.Quality has been horrible for a long time. Also,only tighten it with a socket enough to compress the seal,which isn't much,any more can distort the switch housing and bind the internals. Any excess torque on that switch housing can distort it enough to bind or leak.

 

[451Mopar]

I think the 3-prong switch needs the valve body rooster comb shift lever that has the plastic guide part where the switch is. The earlier single connection NSS switch, I don't think has the plastic guide. If not the switch, the plastic guide could also be broken?
A-727 Detent Lever Plastic Wiper 727-22420W

 

[Dustyrides]

Based on the production date courtesy of turbine68rt, I ordered a new switch which for 68 is the single connection which was measurably, shorter than the 3 prong. Before I installed the new switch I verified that the linkage worked for all positions. I installed the new switch just slightly above snug and topped off fluid. It behaves fine in neutral but if shifted to park it starts making the ratcheting sound and the wheels start turning like it's in gear (currently on jack stands). I Don't think the switch is the culprit because I could screw the switch all the way in while the linkage was in park. I'm confounded because it didn't do this before I changed the switch (the first time). Maybe I damaged something internally when I installed the 3 prong switch last time?

 

[QuickBpBp]

It's not fully engaging park that is the ratcheting sound you are hearing. Loosen the switch and see if it engages in park fully by trying to spin a rear tire. If it does something is up with the new switch and the rooster comb not allowing full travel to engage in park. Here are the rooster combs and the matching switches (pic stolen from another member). You may need to drop the pan and lay eyes on what is going on.

 

[RemCharger]

If the wheels are spinning on the jack stands you can't just fire it into park

( ... well I guess you could,, but it would make a terrible ratcheting noise..)

 

[T Brashears]

If you have a 3 pin switch on an early rooster comb the plastic on the switch is not chamfered enough for the rooster comb to operate smoothly.I would disconnect the linkage and try it just in case. Linkage should be adjusted with the selector lever fully to the rear and park pawl engaged. Shifter in park,the shift rod should fit smoothly into the hole in the lever without moving it.

 

[Dustyrides]

Thanks guys! I will look at all this over the weekend. Good to know I can see the action if I remove the pan.