Neutral Safety Switch Question:

[Captain D]

Hello all,

I just had a quick question about the neutral safety switch on my 727 torqueflite automatic / 69' Charger,  if I may please.  Basically,  although its a new rebuild, we've had a little leakage (I've heard that they tend to be). When using a good pen-light up under there, I noticed that the only spot with the leak is where the neutral safety switch adjoins to the connector. I swapped out both a new neutral safety switch + a new connector,  but no change.  Since everything is new, I was curious to see if anyone here has had the same issue and if you used any form of RTV Sealant to simply reduce the amount of drippage at this specific point?

As a side note, I 'thought' I read of a 3M white sealant used on diesel trucks that is supposed be amazing in sealing,  but I don't recall the exact name or item/part number - does anyone know what this may be, or any sealant in general,  that may work best in preventing the switch/connector point from dripping?

Thank you for any input,
Aaron

[b5blue]

Teflon tape.   

[John_Kunkel]

There is a cupped rubber/metal gasket under the switch, is it in place? If so, they do wear out with repeated installations.

[Captain D]

Hello gents & thank you for the replies,

Yes, the cupped gasket under the switch is brand new as well. It all looks dry at that point - just where the connector adjoins to the switch is moist. Dialectic grease was used around the lip, so hopefully it should protect the inner plug-ins. As for a possible external sealant,  I 'think' the 3M sealant I was referring to in my initial post was the 3M Marine Fast Cure Sealant. I'm assuming that this stuff should be okay to use, and be 'sensor safe' in using it near wiring connectors,  but if not, perhaps I could simply opt with the Permatex Ultra Black instead.

Thanks again for the replies & any further input,
Aaron

[John_Kunkel]

Your description sounds like the leak is coming from the point where the plastic terminal part of the switch is crimped to the metal body of the switch. If so, the switch is faulty and needs to be returned.

Any attempt to seal this area while the fluid is still leaking will probably fail; the switch should be removed and thoroughly cleaned before the (ATF resistant) RTV is applied.

[RECHRGD]

A few years back I bought a complete rebuilt 727 from Cope Racing.  It leaked through the NSS.  When I called him, he said that there had been a bad bunch manufactured that were out in circulation.  I installed my old one and have had no problems since......

[Captain D]

Hello all,

Thanks again for the input and I wanted to post an update.  Basically,  the true source of the leak is where the neutral safety switch gets threaded into the aluminum transmission casing / housing. A local shop put the car up on a lift to get a better look - turns out, the threads seem to be a little stripped on the casing / housing itself. The shop tried to tighten it up as much as they could, based on the threads,  and also installed a better O-ring than what the neutral safety switch actually came with. And, as for sealant,  I insisted that they use the 'Ford Motorcraft sealant for 7.3 litter diesel engines.'

We let the car set for about and hour and 15 minutes before I drove it home (a 10 minute drive) and I went out about 12 hours later to take a peek up underneath and, unfortunately,  there still seems to be a little leak.  The transmission was rebuilt only about 2 years ago, so I can try to contact the rebuild shop to see if they will try to correct the problem but if not,  does anyone happen to know what it may cost to have the aluminum casing re-tapped,  by chance?  I hope that the pan won't have to be pulled.  But, perhaps it may just so that no metal shavings don't get mixed into the transmission fluid.

Any insight on the possibility of using a helicoil as a cheaper alternative? If so, any idea on which size / part number I should look to purchase for my Torque Flight 727? For instance,  is it a 3/4 - 16?

Thank you again,
Aaron

[John_Kunkel]

The threads are 3/4"-16 but there only about 5 threads in the case so it might be difficult to get a Heli-Coil in there.

I wouldn't expect any sealant to seal well unless it sits overnight before being exposed to fluid.

[Captain D]

Many thanks for the reply. Hmm, yeah,  not the type of news anyone wants to receive.  When I applied extra sealant around the lip of the switch (up against the aluminum casing), I was able to reduce the slight leak considerably.  Even though its not the 'correct' method,  its cheaper than a new casing altogether.

I'll be sure to call the local transmission shops to see about the helicoil route as a slight possibility perhaps.  But, if sealant is my only option,  I suppose I can purchase a fast cure and apply heat in an effort to try and get it to seal as quickly as possible. I'm getting to that point where I feel like saying the heck with the small back-up lights. Perhaps it may be worthwhile to drain out the fluid, seal up the threads as much as possible,  then re- add the fluid a day or two later.

Thank you again for the many replies and input as I certainly appreciate your time,
Aaron

[Captain D]

Hello all,

'Thank you' once more for all of the tips, info, etc. on the NSS! To give you an update, I ended up taking it to a new shop with a solid / reputable track record for honesty and integrity in order to get a second opinion on the threading (the first shop stated that some of the threads were a little stripped and wanted to do a $300 repair job), but once they got it up on the lift, the new shop checked it out very thoroughly and noted that they're fine! I had a feeling that shop #1 was just trying to squeeze more $$ out of customers, both from my prior experience and from what I've heard from others in the surrounding area, so I wrote down the tips in which we chatted about regarding the Teflon-Tape and we went that route.

Since the threads were looking good, they used the tape and as for the sealant - I ran into an older / distant cousin who also works at a garage and he strongly recommended a sealant called, 'The Right Stuff' to apply around the lips:

http://www.autozone.com/sealants-glues-adhesives-and-tape/sealant/permatex-4-oz-automatic-tube-the-right-stuff-gasket-maker/82550/?_requestid=5630164

This sealant forms an instant seal before any of the fluid can come in contact with the settings so that "vehicles can return to service immediately," and the new shop that did the work was very impressed with the results and noted that they plan to use it in their garage on future vehicles. I did some research in checking the reviews on this sealant prior to the work being done, and it has received a high degree of feedback from users - even when applied in colder temperatures. Anyhow, I went for a longer drive, parked the car over night in the garage, and went out the next day to check for any leaks - everything is dry! I've been doing this for the past few days and so far, all is well - a perfect Christmas gift!

Anyhow, I just wanted to keep you updated and to 'thank you' for lending your knowledge and skill to help me out as I greatly appreciate it. Take care and I hope that everyone has a wonderful holiday Christmas season!
High regards,
Aaron