Just had mine replaced. Dealer found a P0708 Hard Shift Code. Wow, I thought this trans. shifted nice before but now it is unbelievable.By the way, the upgraded switches are black now.

how many connectors are on that new switch?

I stock the brown switch, thought that was the latest design Eric.

I've been curious about the switch color since I first read about the improved brown switches. So I crawled under my truck and the switch on it is black. Build date was 01-15-04, so either it's the old switch from left over inventory, or the new ones are black.


Is there a difference in the number of connectors on the old black switch versus the new brown ones?


Or some other way to tell if it's different than the old black ones?

The tan ones have a round plastic water cap/seal around the shaft hole.

There is supposedly a very new one that has an entirely different harness and receptacle. That may be the black one on the o4. As Eric asked, how many connectors are on the. The old styles had two, the new one has one big one.

HAVE A LOOK (http://dieselplace.com/forum/forum_posts.asp?TID=6168&KW=+nsbu)

Mike, Tan, brown. I assume we are talking the same switch. Regardless, its not black


Hoot is right, I am referring to the new NSBU switch that GM is using. I notice its on all of the new 4L60's and 4L80's. Not sure about the Allison's yet, havent seen it on them.

Thanks Hoot.


Eric,


I just got under my truck again and it has the big single connector for the wiring harness, looks like the one in the link Hoot provided. Is that what you're referring to on the 4L60 and 4L80 transmissions?

Zeeb, yes thats it. They must have wired in the new connector.

Ok, now I'm confused. Truck built third week October 2003 (04 model) and my switch is black with two harness connectors. Is there a bulliten on these? Is the newest version black with two connectors? Do I need to pester my dealer?

Well I'll try and answer your questions based on what I've read here on the forum about this switch business.


Evidently there is a problem with the original black switches and water getting into them. So they came out with a brown/tan switch which has a cover over the shaft seal to help keep the water out. As I understand it, this brown/tan switch has the two connectors for the wiring harness that the original black switch had.


Now there is a new switch which has some other mods, including a single larger wire harness plug and the cover over the shaft, as well as not having the metal alignment tab for install.


If you've not read the thread on the link Hoot provided you should read it. It contains a bulletin from Allison about the new switch and the changes. If your truck has the two connectors, it requires a mod to the wiring harness to install the newest black switch.


I don't know if there is a bulletin on the newest switch, but IIRC, there is one for the water problem. Also, I don't think your dealer will change it unless you've got a problem with it, or you're lucky enough to know the dealer really well and they'll do it for you anyway.


Hope that helps.Edited by: Zeeb

When my dealer changed switches he also installed new harnesses with it. Don't know if that answers any questions.