Help Needed: Need Transmission Neutral Safety Switch for '70 Dodge Charger - 727 Trans (all I try leak like crazy)

[matchek]

Would you please help would you happen to know or have the recommended Transmission Neutral Safety Switch for a '70 Dodge Charger - 727 Transmission? I have tried one from Amazon (Standard Motor Products -NS-11T) and the mechanic bought one from Napa ("MPE) and they both leak. The one from MPE leaks worse. Would you happen to know the recommended part of know of a Mopar part? This has been a problem. I don't know if it was leaking before the first mechanic but I had him replace it with the one from Amazon because the car would have to cycle several times before starting. Both me and my mechanic look forward to any guidance. I would think this is a common part.

 

[Ray70Chrg]

Would you please help would you happen to know or have the recommended Transmission Neutral Safety Switch for a '70 Dodge Charger - 727 Transmission? I have tried one from Amazon (Standard Motor Products -NS-11T) and the mechanic bought one from Napa ("MPE) and they both leak. The one from MPE leaks worse. Would you happen to know the recommended part of know of a Mopar part? This has been a problem. I don't know if it was leaking before the first mechanic but I had him replace it with the one from Amazon because the car would have to cycle several times before starting. Both me and my mechanic look forward to any guidance. I would think this is a common part.

I've had the same problem with leaking as you describe. I know it's not from some other location on the trans because I've actually watched the fluid slowly seep from between the plastic and metal bodies. I wrap some blue paper towel around the switch to keep the fluid from migrating around the trans oil pan and causing confusion about where the leak is coming from. The shift selector seal is also a concern and can sometimes fool you into thinking that the nss is the problem. This is not the case with me, and I am certain that the nss do have a leaking problem. I've tried 3 new ones in the 7 years I've had this car.

 

[matchek]

I just had the other seals you mentioned replaced. The mechanics says it on only leaking from the neutral safety switch. It was not leaking when I left the shop last week but it is now . This is my second nss.

 

[pnora]

Here we go again. You get piss poor mechanics like a dog get fleas.

 

[Don selleck]

I bought a new one about 5 years ago worked for about 10 minutes, but no leaks at least. ended up finding a used old one that still worked

 

[matchek]

Here we go again. You get piss poor mechanics like a dog get fleas.

Please let's get passed beating up the mechanics. I get it - the mechanic warning was helpful in the beginning but now it's taking up space from someone who has helpful input. This mechanic actually recommended asking this thread as someone here may know better and will help us both save time and me money. He is doing something else and trying to knock this out - otherwise I may have to take it someone else afterwards which trying to save time.

 

[matchek]

I bought a new one about 5 years ago worked for about 10 minutes, but no leaks at least. ended up finding a used old one that still worked

Hi Don would you happen to know if the used old one was an original part or just an aftermarket? Anyone to tell the make and model number?

 

[Ray70Chrg]

I just had the other seals you mentioned replaced. The mechanics says it on only leaking from the neutral safety switch. It was not leaking when I left the shop last week but it is now . This is my second nss.

I agree completely with the mechanics observation. It will very, very slowly seep out even when the car hasn't been run. The switch is constantly submerged in trans fluid. Don't know what the answer is to this problem. There's only a couple of companies making this switch. Maybe only one and the others are just repackaging the switch to have it available to their customers.

 

[pnora]

Please let's get passed beating up the mechanics. I get it - the mechanic warning was helpful in the beginning but now it's taking up space from someone who has helpful input. This mechanic actually recommended asking this thread as someone here may know better and will help us both save time and me money. He is doing something else and trying to knock this out - otherwise I may have to take it someone else afterwards which trying to save time.

Get am OEM switch. Google these numbers and make sure it is oem and not an aftermarket replacement. 2932820, 2926495, 4057750

 

[turbine68rt]

for Mopar Neutral Safety Backup Switch A727 A904 Plymouth Dodge Chrysler 340 440 | eBay

 

[Don selleck]

Hi Don would you happen to know if the used old one was an original part or just an aftermarket? Anyone to tell the make and model number?

its was OEM never heard of an aftermarket that did work correctly. they maybe out there though

 

[Smokinnjokin]

I wonder if white teflon tape on the threads would do the trick.

 

[Black_Sheep]

Make sure the cupped sealing washer isn't split or damaged from overtightening. While you're at it, make sure there isn't an old one stuck to the trans case and check the sealing surface of the trans case for damage.

 

[Fran Blacker]

5 Pack WASHER TF6 904 & TF8 727 Neutral Safety Switch Torqueflite 6 8 A904 A727 | eBay not mine

 

[beanhead]

Wow I've never had them leak, aftermarket or otherwise...I get that kind of stuff from here:

Classic Transmission Solutions

I'd be checking the sealing surfaces and washer type very closely.
I'd also get under there and re-tighten it after it's been heated up and cooled down a time or three as well...the transmission case is aluminum afterall so there's gonna be some expansion/contraction going on related to temperature.

 

[VANDAN]

Mat, I've had the same trouble on my '70 Challenger. I got lucky, and found an OEM piece. So far, no leaks, but haven't driven the car much...

 

[OKDart]

I’ve had a new one leak from the plastic at the crimp. Eventually you’ll get one that doesn’t leak. This only rewards the shitty manufacturer by selling more. Me personally, I’d put the non working original back in and just ground the starter relay so it will start in any gear.

 

[matchek]

Get am OEM switch. Google these numbers and make sure it is oem and not an aftermarket replacement. 2932820, 2926495, 4057750

Thank you very much Pnora! By the way, it appears the 2925496 was for after '78 and 4047750 even after that. Are these numbers also interchangeable? I guess the switch didn't change much?

 

[Ray70Chrg]

Get am OEM switch. Google these numbers and make sure it is oem and not an aftermarket replacement. 2932820, 2926495, 4057750

Ordered a oem #2926495 on Ebay today. The switch is new, never installed however the small box it comes with shows its been around for a while. $45 for the switch, $16 more for s/h and tax. If this fixes the leaking problem it will be worth the cost. Ironically, the 1st time I went into the trans, I changed the switch only because I removed the pan. May as well change it while I'm here. It possibly could have been the original, I'll never know.

 

[matchek]

I was able to order two new NSS # 2932820 - supposedly New Old Stock. Thank you so much for your help for guiding me on the order. With the part number was able to find NOS.