LB7 not shifting

[Tano]

I went to my buddys earlier and roughly 2 hours later i left. Leaving his house i noticed it seemed to be stuck in second gear. From a dead stop its in (what im guessing is second gear) and just stays in that gear. I tried shifting on the collum and also turning on and off tow/haul and neither made a difference.

It drove fine to his house and i havent noticed any shifting problems lately.
About six months ago i had a similar problem and it ended up being the NSBU switch. I just looked at the NSBU switch and it has quite a bit of mud on it, but that mud for the most part has been there for several days.
Today is the first day it has gotten below freezing so im not sure if that has something to do with it.

3 days ago I hada heater hose connector explode on me and ended up losing 90% of the coolant. This morning I replaced the connector and refilled the coolant and it has drove fine all day up until this.

So im not sure if it could be the NSBU again or if its in limp or what. I just drove it home and parked it for the night.
Any and all input is appreciated. Seems like its been 1 thing after the other this month with the ol LB7...

 

[dirtydmax]

any codes?

 

[Tano]

Not sure as of yet, I recently did the AIH delete and haven't bypassed the code yet not sure if it threw one or not. Gonna get it scanned tomorrow.

 

[NKlamerus]

Or light?

 

[Tano]

Just pulled codes. It threw p0708 and p0700. I willl also note it still was stuck in third on the way to work this morning but just now on the way to come to O'Reillys it was shifting fine

 

[Mike L.]

Internal mode switch inside the pan could be your problem.

 

[Tano]

Internal mode switch inside the pan could be your problem.

It definitely seems to be intermittent. After going a few places today it'll shift fine from one place to another then won't to the next.
Thanks for the input Mike, is there a way I can check the switch before replacing it?

 

[Tano]

And I also did not clear the code, would that effect anything?

 

[Mike L.]

Clear the code and see if it comes back. It could make a difference.

 

[Tano]

The gear indicator is also not working properly on N and D. From everything I've researched its all pointing at the NSBU

 

[Tano]

Clear the code and see if it comes back. It could make a difference.

Alright, thanks for your time Mike. I may just take it to the same trans shop that replaced the NSBU last time

 

[Mike L.]

Alright, thanks for your time Mike. I may just take it to the same trans shop that replaced the NSBU last time

The internal mode switch IS the NSBU switch for the LBZ.

 

[Chevy1925]

The internal mode switch IS the NSBU switch for the LBZ.

from what im reading, hes talking about his LB7

 

[Tano]

Yep talking about my lb7. The selector that shows what gear your in is acting up

 

[Mike L.]

from what im reading, hes talking about his LB7

OOPS, thought I saw it as a Z instead of 7.

 

[Chevy1925]

OOPS, thought I saw it as a Z instead of 7.

O.L.D. is killer on the eyes my friend :hug:

 

[Tano]

So i've decided to say screw it and am gonna change out to NSBU. Luckily Oreillys has one in stock, it just kills me to pay 165 for one.......................

 

[The Neens]

So i've decided to say screw it and am gonna change out to NSBU. Luckily Oreillys has one in stock, it just kills me to pay 165 for one.......................

Have you done a search for a local Allison dealer?

 

[Mike L.]

The Allison NSBU has better sealing against moisture then the conventional 4L80E switch.
Just so you know. Either one works; one just seals better.

 

[mike diesel]

I just called my local allison dealer. Double plug NSBU is $78 and single plug NSBU is $55.