Allison 5sp: Speed sensor issue LLY

[Chris M]

Hey Mike I'm wondering if ya could help me out since I can't find anything online or anywhere tbh.

I've got 2004.5 LLY. I've been having his issue with the speed sensor p0500 code and limping my trans when I get to about 30-40 mph. I've replaced the transfer case, replaced the speed sensor twice and still no luck at fixing it. I'm lost at what it could be.

Throws p0700 / p0500 I had it connected to snap on from a buddy at his shop and it's losing communication with TCM and speed sensor in the transfer case. I'm lost at what to do next. Don't wanna just throw parts and money at it.

Any help would be appreciated. Don't know if it could be the harness to speed sensor or what. can't find anything online bout it or a diagram on the wiring where it goes and comes from etc.

replaced TCM, had transfer case out and had it checked out by a trans shop and to make sure everything was good with transfer case. Was told it looked great no issues. Already had pump run kit installed in it and everything.

 

[Chris M]

I had it aligned not long ago and leveling kit removed and factory keys in it that I bought because it rode like shit, replaced tie rods because they was bad and had them go through check everything and thought maybe that was cause was from leveling kit and that it ate up the rear bearings of output shaft of transfer case at 236k Miles no pump rub kit in it. Only thing I was told was that control Arm was going to need replaced probably soon on passenger side but wasn't bad yet.

I'm not sure if front speed sensor maybe bad did have one get pulled a little from stretching on the leveling kit. But all it did was pull the plastic snap from under finder not the connection on driver side. Snapped it back in fine. Didn't look like any tears or anything but not sure if the sensor maybe clogged with brake dust etc could it cause rear speed sensor to be thrown off? Should I remove them from hub and clean them or replace them? Hubs are good.

 

[skintback]

If you don't have a good scanner to monitor everything while driving it down the road. I would start by pulling the speed sensor in the transfer case out and make sure it is not getting chewed on by touching the gear it picks up the signal up from. Then i would check both front wheel bearings for play and if no play i would change out the driver side wheel speed sensor wire you say was pulled on. Also check all wires from trans/transfer case to under the hood to make sure there are no bear wires rubbing on anything. Check all grounds as well.