Transmission issue or wiring??

[2004LB7]

I thought you weren’t supposed to put dielectric grease inside the connection, just over the top to encapsulate it ??‍

Also that stuff you spray on battery terminals, do not spray it on first then make your connection, my dad learned that the hard way ?

I don't think he was referring specifically to that connector but connectors in general. Many have grease or operate just fine with it. So, what makes this one different???

I learned about spraying connectors and plugging them in a while back when I did that and started seeing them pop right off a few seconds later. Was a little baffled until I realized what was happening

 

[gmduramax]

I don't think he was referring specifically to that connector but connectors in general. Many have grease or operate just fine with it. So, what makes this one different???

I learned about spraying connectors and plugging them in a while back when I did that and started seeing them pop right off a few seconds later. Was a little baffled until I realized what was happening

Only thing I can think of is it adds capacitance to the wires that the TCM isn’t accounting for ??‍
Once the fluid degrades or becomes contaminated it doesn’t become more conductive.

 

[2004LB7]

Only thing I can think of is it adds capacitance to the wires that the TCM isn’t accounting for ??‍
Once the fluid degrades or becomes contaminated it doesn’t become more conductive.

Capacitance is a possibility. Especially since the TCM is driving inductive loads with those coils. Maybe some kind of LC feedback?

Fluid has to be very contaminated with lots of metal before it starts to become conductive. Ever stick your meter leeds into so lithium or moly grease and see it doesn't conduct. And they are packed much more then you'd ever get from the transmission. I've even checked graphite grease that was deep black and it was not conductive. I think conductive grease or oil has something else going on like the base fluid is different.

 

[Cougar281]

I don't think he was referring specifically to that connector but connectors in general. Many have grease or operate just fine with it. So, what makes this one different???

I learned about spraying connectors and plugging them in a while back when I did that and started seeing them pop right off a few seconds later. Was a little baffled until I realized what was happening

Correct, I wasn't referring the trans connector. It's not unheard of to see people putting dielectric grease in connectors to keep water out though, and I don't know that I've heard of it causing issues..

 

[Ron Nielson]

Other cars, such as my Mercedes, have similar problems, except that their issue is engine oil penetrating the wiring connections to the ECM. So it's not just trans fluid that has this property.

 

[Sickofthisshet]

Ok I need a little help. I had to use Advance to order the NSBU but the only GM available was for the 6speed. So I ordered the next (most expensive in hopes of better quality LOL) for $170 and I just found the same one on eBay for $40. Also replaced the transmission harness inside the plan to stop the fluid leaks.
Started it up and it did not work. Before I found out the NSBU installed was a 4 speed I had tried multiple ways of doing a TCM reset, nothing worked obviously since that wasn’t the right part but is it possible I reset the TCM and it has learned positions of the 4 speed sensor? If so does anybody know how to reset it again because I tried 10 different ways of pressing the petal this way and slapping your knee thataway and don’t know if any did anything ?
And I’m still to the point of is this even the problem or did my transmission fail… Because I was able to unplug the new harness and get 3rd gear back again for limp mode.

Also need to address this just in case:
So before (with the 4sp NSBU) when I was finally able to figure out a way to see the dash again it was:
Start fine in park- go down one and my reverse lights did come on but dash showed N
Go down one more and reverse lights off/technically in neutral but dash was blinking the R.
So do I listen to the truck and assume 1 down is truly reverse and 2 is N despite the dash reading, or would I shift down once to where the dash showed N and install the NSBU according to that?

And let me throw another curve for anybody willing to listen and offer support. The transmission in the truck was installed by the previous owner about a year or 2 before I got it and I’m looking back at old photos when the truck first tore up and see the NSBU on it is part number 12450016. It then has 10:05:11 and under that 2011…So one - is that a time and date stamp? Lol. Two - I look up this part and it goes to a 4l60e/4l80e however my truck is listed in interchangeable parts but that makes absolutely no sense how that could be. And three… when the first NSBU didn’t work I forgot about him replacing the harness to it when the 2nd NSBU was purchased. Is the harness pretty universal or could that be an issue if when he bought the (wrong 4 speed) NSBU the rep also sold him the harness and I’m assuming making sure it went to that?

 

[Sickofthisshet]

Ok I need a little help. I had to use Advance to order the NSBU but the only GM available was for the 6speed. So I ordered the next (most expensive in hopes of better quality LOL) for $170 and I just found the same one on eBay for $40. Also replaced the transmission harness inside the plan to stop the fluid leaks.
Started it up and it did not work. Before I found out the NSBU installed was a 4 speed I had tried multiple ways of doing a TCM reset, nothing worked obviously since that wasn’t the right part but is it possible I reset the TCM and it has learned positions of the 4 speed sensor? If so does anybody know how to reset it again because I tried 10 different ways of pressing the petal this way and slapping your knee thataway and don’t know if any did anything ?
And I’m still to the point of is this even the problem or did my transmission fail… Because I was able to unplug the new harness and get 3rd gear back again for limp mode.

Also need to address this just in case:
So before (with the 4sp NSBU) when I was finally able to figure out a way to see the dash again it was:
Start fine in park- go down one and my reverse lights did come on but dash showed N
Go down one more and reverse lights off/technically in neutral but dash was blinking the R.
So do I listen to the truck and assume 1 down is truly reverse and 2 is N despite the dash reading, or would I shift down once to where the dash showed N and install the NSBU according to that?

And let me throw another curve for anybody willing to listen and offer support. The transmission in the truck was installed by the previous owner about a year or 2 before I got it and I’m looking back at old photos when the truck first tore up and see the NSBU on it is part number 12450016. It then has 10:05:11 and under that 2011…So one - is that a time and date stamp? Lol. Two - I look up this part and it goes to a 4l60e/4l80e however my truck is listed in interchangeable parts but that makes absolutely no sense how that could be. And three… when the first NSBU didn’t work I forgot about him replacing the harness to it when the 2nd NSBU was purchased. Is the harness pretty universal or could that be an issue if when he bought the (wrong 4 speed) NSBU the rep also sold him the harness and I’m assuming making sure it went to that?

Oh, also if my issue was the NSBU or the harness — why didn’t it throw the truck into limp mode? I havnt physically got this truck to even lock into gear in months since it originally tore up…then I unplug the harness and it suddenly drives. After I paid $300 to tow it home 2 miles ?? Well it would go in reverse but not drive at all. Then when I changed the switch we lost reverse then too. ???

 

[Bdsankey]

Dual Plug Style: 29540479
Single Plug Style: 29541852

These are the genuine GM numbers. You want only Genuine GM or Allison for this component. If you can't source one locally let me know and I can get one headed your way. Hopefully you have the single plug style as they're far cheaper.

Ok I need a little help. I had to use Advance to order the NSBU but the only GM available was for the 6speed. So I ordered the next (most expensive in hopes of better quality LOL) for $170 and I just found the same one on eBay for $40. Also replaced the transmission harness inside the plan to stop the fluid leaks.

I provided the PNs above, you could have gone to Rock Auto or any online GM/Allison parts house and ordered them.

Started it up and it did not work. Before I found out the NSBU installed was a 4 speed I had tried multiple ways of doing a TCM reset, nothing worked obviously since that wasn’t the right part but is it possible I reset the TCM and it has learned positions of the 4 speed sensor? If so does anybody know how to reset it again because I tried 10 different ways of pressing the petal this way and slapping your knee thataway and don’t know if any did anything ?
And I’m still to the point of is this even the problem or did my transmission fail… Because I was able to unplug the new harness and get 3rd gear back again for limp mode.

I've never "relearned" an NSBU. It's outputs are not coded in any manner that needs to be learned, if you installed it with the gear selector in neutral as they indicate it shouldn't be an issue and may only take minor adjustment beyond that.

Also need to address this just in case:
So before (with the 4sp NSBU) when I was finally able to figure out a way to see the dash again it was:
Start fine in park- go down one and my reverse lights did come on but dash showed N
Go down one more and reverse lights off/technically in neutral but dash was blinking the R.
So do I listen to the truck and assume 1 down is truly reverse and 2 is N despite the dash reading, or would I shift down once to where the dash showed N and install the NSBU according to that?

When installing a new NSBU, the dash indicator doesn't matter. Physically put the transmission in neutral (2 clicks rearward from the fully forward position). You are installing THE part that will tell the dash where the trans is physically placed with the gear selector.

And let me throw another curve for anybody willing to listen and offer support. The transmission in the truck was installed by the previous owner about a year or 2 before I got it and I’m looking back at old photos when the truck first tore up and see the NSBU on it is part number 12450016. It then has 10:05:11 and under that 2011…So one - is that a time and date stamp? Lol.

No clue on your stamping questions.

Two - I look up this part and it goes to a 4l60e/4l80e however my truck is listed in interchangeable parts but that makes absolutely no sense how that could be. And three… when the first NSBU didn’t work I forgot about him replacing the harness to it when the 2nd NSBU was purchased. Is the harness pretty universal or could that be an issue if when he bought the (wrong 4 speed) NSBU the rep also sold him the harness and I’m assuming making sure it went to that?

I do not know the wiring difference between the 4L60/4L80 NSBU and the Allison, I've never installed the wrong one with matching pigtail.

Oh, also if my issue was the NSBU or the harness — why didn’t it throw the truck into limp mode? I havnt physically got this truck to even lock into gear in months since it originally tore up…then I unplug the harness and it suddenly drives. After I paid $300 to tow it home 2 miles ?? Well it would go in reverse but not drive at all. Then when I changed the switch we lost reverse then too. ???

What do you mean by "why didn't it throw it into limp mode?", meaning why didn't it lock into 3rd gear? The truck had zero idea what gear it was in thus getting odd readings. Once you unplugged the trans it went into a mechanically locked 3rd gear, meaning with all solenoids deenergized you will hydraulically have 3rd and reverse.

The truck won't default to third gear just because it doesn't understand the NSBU reading. Usually they say range shift inhibited or similar for NSBU issues, or they simply won't start.

 

[Sickofthisshet]

I provided the PNs above, you could have gone to Rock Auto or any online GM/Allison parts house and ordered them.



I've never "relearned" an NSBU. It's outputs are not coded in any manner that needs to be learned, if you installed it with the gear selector in neutral as they indicate it shouldn't be an issue and may only take minor adjustment beyond that.


When installing a new NSBU, the dash indicator doesn't matter. Physically put the transmission in neutral (2 clicks rearward from the fully forward position). You are installing THE part that will tell the dash where the trans is physically placed with the gear selector.


No clue on your stamping questions.


I do not know the wiring difference between the 4L60/4L80 NSBU and the Allison, I've never installed the wrong one with matching pigtail.


What do you mean by "why didn't it throw it into limp mode?", meaning why didn't it lock into 3rd gear? The truck had zero idea what gear it was in thus getting odd readings. Once you unplugged the trans it went into a mechanically locked 3rd gear, meaning with all solenoids deenergized you will hydraulically have 3rd and reverse.

The truck won't default to third gear just because it doesn't understand the NSBU reading. Usually they say range shift inhibited or similar for NSBU issues, or they simply won't start.

Ah I’m sorry, I assumed once it wouldn’t go anywhere that was my limp mode. I understand what you mean now.
I don’t have any problems starting and never have. Just won’t lock into any gear, don’t notice any difference in rpm between park-reverse. I’ve ordered new parts and will give it another go when they get here.


This is the 4 speed switch and connector ordered. I don’t know where the confusion came from between the 4 & 5 speed but it says even the harness is not compatible with the 5 speed at all. Not sure why, I can’t find much online about the 5 speed connector. All I can find is the AC Delco but they’re $100 together. Could you help me find that through GM?

 

[Ron Nielson]

Maybe some additional info here https://www.sellmanuals.com/wp-content/pdf/Allison 1K 2K Service Manual.pdf

 

[Sickofthisshet]

Maybe some additional info here https://www.sellmanuals.com/wp-content/pdf/Allison 1K 2K Service Manual.pdf

That doesn’t go past section 1 without ordering it ? I bet I can find one though. I’m very interested to see why the wires are different if the plugs are the same.

 

[Bdsankey]

Ah I’m sorry, I assumed once it wouldn’t go anywhere that was my limp mode. I understand what you mean now.
I don’t have any problems starting and never have. Just won’t lock into any gear, don’t notice any difference in rpm between park-reverse. I’ve ordered new parts and will give it another go when they get here.


This is the 4 speed switch and connector ordered. I don’t know where the confusion came from between the 4 & 5 speed but it says even the harness is not compatible with the 5 speed at all. Not sure why, I can’t find much online about the 5 speed connector. All I can find is the AC Delco but they’re $100 together. Could you help me find that through GM?

You're looking for the OEM connectors?


Fleece FPE-HAR-GM-NSBU-0104 or DHD 100-448 are solid options. Fleece runs $79.99 + shipping and DHD is $89.95 + shipping, both work very well.


If you need the NSBU & plugs, Merchant 10499 is also another option as it's a NSBU and connectors for $289.94 to your door.

 

[Ron Nielson]

That doesn’t go past section 1 without ordering it ? I bet I can find one though. I’m very interested to see why the wires are different if the plugs are the same.

I intended to attach this one https://s7609befdab33e790.jimcontent.com/download/version/1631817249/module/7046708813/name/Allison 1000-2000 Series Service Manual.pdf

Website says tooooo large to post the file directly