[Bill Gisse]

Ratlover what is the significance of the little box on the side of tjhe tranny being tan or black. Have an Allison and haven't looked for the box yet. Thanks.

 

[ratlover]

do a search on NSBU switch for lotsa reading and there should be some instructions on how to change it. There should aslo be some pics of em if you are unsure of what you are looking for


The one that comes from factory is black. Its prone to taking a dump when it gets wet. Mine died withing 5k miles I believe. It will send your truck into "limp" mode. This means you have 3 choices. Park, nutral and 3rd. You start out in 3rd and your truck will stay in 3rd, no reverse and no 1-2, 4-5, just 3rd. Most times if you cyclce the grear shifter a bunch of times it will start to work again or it did for me. The problem was also intermitnet. There is a TSB on it. The replacement switch is tan in color and is an actual allison switch, i think you can get it for like 50$ from Eric(dmaxallitech) if its not covered under warantee and its a pretty easy replacemnt.

 

[403turbo]

Well I see this is for Ratlover but the answer is pretty common so.....


The little box is called the NSBU nuetral safety back up switch, the black ones were the old version, they had problems with the switch dying and causing the PRND display to blink and the truck to no go into gear among other weird problems.





The Tan version is the new one with most of the problems fixed, some have still had problems but they are much better than the black ones.


Pretty easy to change, do some searches on the forum there is lots of details.


hope that helps

 

[403turbo]

ratlover....quick on the draw