1966 727 Neutral Safety Switch replacement

[Ross Wooldridge]

The NSS on my wagon has been acting up, and I finally had to resort to grounding it out, which of course is not the safest thing.

I sourced a correct NOS replacement (it was actually kind of hard to find), but I thought I'd ask a few questions here before I go ahead and swap it out.

1) It looks like the original switch is threaded all the way in. Is it worthwhile seeing if I can get another turn out of it to see if it will make better contact with the rooster comb? Do the rooster combs wear away (like fuel pump push rods)?

2) I think it unlikely that the above will fix things, and I've been told that sometimes these switches just fail... I can imagine that this switch has many many years and miles on it. However, if the new switch threads all the way in, how can I be sure it's not suffering from the same thing as the original - is there a simple and quick way to adjust the height of the rooster comb without dropping the pan to ensure that it's pressing on the switch properly in Park and Neutral (or is it the other way around)?

3) From what I understand, it's a fairly easy swap - unthread the original, thread the new one in.
Do I need to put any sealant/teflon on the threads?
How much trans fluid can I expect to gush out? I am going to lift the car from the driver side at both wheels - fairly high up (I have some robust tall jack stands) so as to make the fluid be more to the other side of the transmission. Any thoughts on that?

Thanks in advance y'all.

 

[Big_John]

Do I need to put any sealant/teflon on the threads?

That's a big no on that. You want the casing of the switch to ground out to the case.

As far as everything else, yea, have a pan ready to catch some trans fluid. How much drains out will depend on how much fluid has drained back from the convertor, the angle of the car etc.

Another turn in on the old one probably won't help even if you could, and I wouldn't try it anyway.

 

[Ross Wooldridge]

Thanks John - I figured on all of the above, but just wanted confirmation.

Cheers!

 

[halifaxhops]

There should be a tapered rubber seal on it also, usually with the new switch.

 

[Ross Wooldridge]

There is. Thanks!

 

[halifaxhops]

Just tight is fine dont go crazy on it.

 

[Ross Wooldridge]

Thanks for the tip.

 

[halifaxhops]

I have done my share of them. What are they running now list?

 

[Ross Wooldridge]

I'm not sure I understand the question... but perhaps you're asking what's available for replacement....

I found NOS, but even aftermarket NSSs were hard to find.

In 67 they switched to the 3 pin NSS which you can find easily, but up to 66 they were the single pin version. Thread depth was different too.

 

[halifaxhops]

I know that just wondering going price have a few of each of the three styles.

 

[Ross Wooldridge]

Hmmm - I don't remember what I paid. I don't think I was gouged, but I don't really have any comparison...

 

[413]

You tighten the switch and that’s it. There is no adjustment anywhere in the system. The switch is spring loaded Inside. The seal usually works very good, and doesn’t need any trick of the day to seal as it should

Make sure to clean the area good Before removing the switch, and after. Sand and dirt can get attached around that switch and will get between the case and seal

if you have a newer valve body with the different style rooster comb for the 3 pin switch it doesn’t always actuate the single pins NSS correctly. I have a car like that and it will only start in N and not P.

1967 used the same single pole switch. It was 1969 that started with 3 pins. The other pins are for reverse lamps. 1968 still has the reverse lamp switch on the column or console shifter. Photo of console shifter reverse lamp switch