Plugging S13 tranny....leaking sensors - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

s73 · 10-09-2009, 12:21 AM

Long story short, my S13 5 speed tranny has a leak through the sensors. Pretty much from all the sensors other than the speed sensor (all the small ones, Reverse, Neutral, 4th gear, and 5th gear sensors)

I have heard most of the sensors are basically useless and i could just plug them up and cut/seal the wires. I plan to just get a new reverse sensor and plug the rest up (would be nice to have reverse lights)

Here are my questions:

1) Is it ok for me to remove the other sensors (Neutral, 4th gear, 5th gear sensors)? Is there any re-wiring I have to do? What do those 3 sensors do? any adverse effects after removal?

2) Do anybody know what I can use to plug those sensor holes? (just find a bolt with the same thread and pitch?)

3) any hints on taking off that tranny fill plug? It’s a super pain in the ass…..

sorry for the long post, any info on this subject would be a great help for me.

Thanks in advance...

g6civcx · 10-09-2009, 09:59 AM

Hey Sam. Glad you made it.

1. Based on my understanding of how the ECU works, no. The 4/5th/neutral sensors don't affect how your car runs. We have been bypassing them for years with no ill effects.

2. Pipe fittings. Basically anything with the same thread will work. You can run some teflon tape over the threads of the fittings and tighten them.

3. You just have to use a 1/2" ratchet. If you do to manage to get it off, I recommend reusing a transmission or diff drain plug as the filler plug. The drain plug has a magnet and the filler doesn't. There's no harm in putting the drain plug on as the filler for extra protection. The transmission and diff plugs interchange.

If you can't get the filler plug off, you can take off the shifter and fill through there. Just make sure you don't overfill.

Just a little more on #1. I have not yet looked at the ECU source code, and I don't anticipate that I will. So there may be something in the ECU that feeds on these sensors, but so far, we haven't been able to notice a change in engine performance.

projectRDM · 10-09-2009, 01:28 PM

Delete them, you'll never miss them.

I always use a pipe plug from the Aeroquip dealer near me, but any decent hydraulic supply store will have scores of correct pitch plugs, seal them with teflon or RTV and thread in.

s73 · 10-09-2009, 11:23 PM

Thanks for the quick reply Ken and the guys!

Those sensors are coming off as soon as i get a chance to do my MTF. Just going to cut the suckers off and seal off the wires with something.

Just wondering, do any of you guys know the actual thread/pitch of those sensors? If not its no biggie, i just have to go under the car and rip one out.

oh ya.....about that fill plug, its not the same as the female plug on the drain plug...for which i was able to loosen with a 1/2 ratchet. The fill plug is a male square plug, they had this special socket for sale online but i was too lazy to order one. i tried to used an adjustable wrench but after one slip i am not risking stripping the plug.

thanks for the reply guys

s73 · 10-10-2009, 12:22 AM

Oh ya, just wondering.....Does the neutral switch sensor has anything to do with starting up the car. (you know, sometimes called the neutral safety swtich....so you will have to push in the clutch to start the car) Or its a totally different part?

g6civcx · 10-10-2009, 08:00 AM

Quote:

Originally Posted by s73

Just going to cut the suckers off and seal off the wires with something.

If you want to do a sanity check, put your multimeter on the two pins and check for continuity.

If you don't know which sensor is which, check for continuity on one sensor while someone shifts gear. Go from neutral to 4th, and 5th.

At some point the continuity will change. This will let you know what the sensor is measuring.

Take the transmission out of the particular gear that is setting off the sensor and note the continuity. This is what it should be all the time so the car doesn't know you're in the particular gear.

Remove the sensor, and insulate the plug.

I know you wanted to cut off the connector and pigtail the 2 wires together, but you would only do that if the sensor is normally closed. For a normally open sensor it would make the car think that you're in gear all the time.

So do this check to convince yourself that it's true. Repeat for the other 2 sensors.

Quote:

Originally Posted by s73

Just wondering, do any of you guys know the actual thread/pitch of those sensors? If not its no biggie, i just have to go under the car and rip one out.

Sorry but I don't.

Quote:

Originally Posted by s73

about that fill plug, its not the same as the female plug on the drain plug...for which i was able to loosen with a 1/2 ratchet. The fill plug is a male square plug, they had this special socket for sale online but i was too lazy to order one. i tried to used an adjustable wrench but after one slip i am not risking stripping the plug.

I forgot. You are correct. I used something like an open end 17mm wrench and it works. Those adjustable wrenches are a pain.

projectRDM · 10-10-2009, 08:55 AM

Quote:

Originally Posted by s73

Oh ya, just wondering.....Does the neutral switch sensor has anything to do with starting up the car. (you know, sometimes called the neutral safety swtich....so you will have to push in the clutch to start the car) Or its a totally different part?

Nothing related to the starting system. The neutral position switch is simply an indicator to the ECU, the car starts through an interlock that requires the clutch pedal be engaged, gear position doesn't matter.

g6civcx · 10-10-2009, 09:38 AM

Quote:

Originally Posted by s73

Does the neutral switch sensor has anything to do with starting up the car. (you know, sometimes called the neutral safety swtich....so you will have to push in the clutch to start the car) Or its a totally different part?

Like Russ said, on the manual car, the neutral switch is not used for anything related to starting.

You have the clutch interlock switch for that. You should bypass the clutch interlock switch circuit anyhow. The blue relay tends to go bad and can leave you stranded.

s73 · 10-11-2009, 01:17 AM

Thanks for all the good info guys, what you guys said made a lot of sense. I guess its a lot better to check with the multimeter then to just cut the sensors off and guess. I was just going to plug the tranny and cut/insulate the wires left over. I am off to pick up a multimeter

thanks guys!

nissandrift · 03-11-2013, 09:26 AM

I know this thread is super old, but for future reference the plugs need to be M14x1.50, or 1/4" pipe fitting plugs.

jackasspyro2 · 03-18-2013, 08:37 AM

Thanks.i was just thinking of deleting mine today add they are leaking.you made it a whole lot easier

Posted from Zilvia.net App for Android

d_nice · 03-18-2013, 12:55 PM

thanks guys have the same issue will use this

s73 · 08-29-2015, 10:44 PM

Sorry to bring back an old thread.....but have some info that may help others when they need to get this done....

I looked into the FSM, its states that all the switches should have continuity when the gear position is in the switch position. (ex. the O.D or 5th switch have continuity only when you put the trans in 5th gear) That means just unplug the switches, seal it up, and you are done....

Also, I had some old Honda Civic oil drain plugs, they are a perfect fit, its m14x1.5 and just the right length to plug the switch holes

10-09-2009, 01:28 PM	#3
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 50 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Delete them, you'll never miss them. I always use a pipe plug from the Aeroquip dealer near me, but any decent hydraulic supply store will have scores of correct pitch plugs, seal them with teflon or RTV and thread in. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

10-09-2009, 12:21 AM	#1
s73 Join Date: May 2009 Location: va Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	Plugging S13 tranny....leaking sensors Long story short, my S13 5 speed tranny has a leak through the sensors. Pretty much from all the sensors other than the speed sensor (all the small ones, Reverse, Neutral, 4th gear, and 5th gear sensors) I have heard most of the sensors are basically useless and i could just plug them up and cut/seal the wires. I plan to just get a new reverse sensor and plug the rest up (would be nice to have reverse lights) Here are my questions: 1) Is it ok for me to remove the other sensors (Neutral, 4th gear, 5th gear sensors)? Is there any re-wiring I have to do? What do those 3 sensors do? any adverse effects after removal? 2) Do anybody know what I can use to plug those sensor holes? (just find a bolt with the same thread and pitch?) 3) any hints on taking off that tranny fill plug? It’s a super pain in the ass….. sorry for the long post, any info on this subject would be a great help for me. Thanks in advance... Last edited by s73; 10-09-2009 at 12:24 AM.. Reason: typo

10-09-2009, 09:59 AM	#2
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	Hey Sam. Glad you made it. 1. Based on my understanding of how the ECU works, no. The 4/5th/neutral sensors don't affect how your car runs. We have been bypassing them for years with no ill effects. 2. Pipe fittings. Basically anything with the same thread will work. You can run some teflon tape over the threads of the fittings and tighten them. 3. You just have to use a 1/2" ratchet. If you do to manage to get it off, I recommend reusing a transmission or diff drain plug as the filler plug. The drain plug has a magnet and the filler doesn't. There's no harm in putting the drain plug on as the filler for extra protection. The transmission and diff plugs interchange. If you can't get the filler plug off, you can take off the shifter and fill through there. Just make sure you don't overfill. Just a little more on #1. I have not yet looked at the ECU source code, and I don't anticipate that I will. So there may be something in the ECU that feeds on these sensors, but so far, we haven't been able to notice a change in engine performance.

10-09-2009, 11:23 PM	#4
s73 Join Date: May 2009 Location: va Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the quick reply Ken and the guys! Those sensors are coming off as soon as i get a chance to do my MTF. Just going to cut the suckers off and seal off the wires with something. Just wondering, do any of you guys know the actual thread/pitch of those sensors? If not its no biggie, i just have to go under the car and rip one out. oh ya.....about that fill plug, its not the same as the female plug on the drain plug...for which i was able to loosen with a 1/2 ratchet. The fill plug is a male square plug, they had this special socket for sale online but i was too lazy to order one. i tried to used an adjustable wrench but after one slip i am not risking stripping the plug. thanks for the reply guys

10-10-2009, 12:22 AM	#5
s73 Join Date: May 2009 Location: va Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	Oh ya, just wondering.....Does the neutral switch sensor has anything to do with starting up the car. (you know, sometimes called the neutral safety swtich....so you will have to push in the clutch to start the car) Or its a totally different part?

10-11-2009, 01:17 AM	#9
s73 Join Date: May 2009 Location: va Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for all the good info guys, what you guys said made a lot of sense. I guess its a lot better to check with the multimeter then to just cut the sensors off and guess. I was just going to plug the tranny and cut/insulate the wires left over. I am off to pick up a multimeter thanks guys!

03-11-2013, 09:26 AM	#10
nissandrift Leaky Injector Join Date: Oct 2003 Location: Raleigh, NC Age: 41 Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	I know this thread is super old, but for future reference the plugs need to be M14x1.50, or 1/4" pipe fitting plugs.

03-18-2013, 08:37 AM	#11
jackasspyro2 Leaky Injector Join Date: Nov 2011 Location: space Posts: 97 Trader Rating: (2) Feedback Score: 2 reviews	Thanks.i was just thinking of deleting mine today add they are leaking.you made it a whole lot easier Posted from Zilvia.net App for Android

03-18-2013, 12:55 PM	#12
d_nice Post Whore! Join Date: Aug 2010 Location: florida Age: 43 Posts: 3,595 Trader Rating: (39) Feedback Score: 39 reviews	thanks guys have the same issue will use this

08-29-2015, 10:44 PM	#13
s73 Join Date: May 2009 Location: va Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	Sorry to bring back an old thread.....but have some info that may help others when they need to get this done.... I looked into the FSM, its states that all the switches should have continuity when the gear position is in the switch position. (ex. the O.D or 5th switch have continuity only when you put the trans in 5th gear) That means just unplug the switches, seal it up, and you are done.... Also, I had some old Honda Civic oil drain plugs, they are a perfect fit, its m14x1.5 and just the right length to plug the switch holes