02 Duramax Allison P0700 and P0872

[GDduramax]

Hello,
So I've been viewing these forums for awhile now and heavily reading all of Mike L's great advice. I've been messing around with these trucks for years and have finally ran into an issue i just cannot figure out. Saturday i changed Filters(internal and spin on) and put new fluid in. I drive a lot of miles over the course of a year so i do this every 15,000 miles or so. Never had an issue. Well after i went through my normal procedure and put it in drive for it to go into limp mode. I dropped the pan again, made sure i didnt damage the harness and checked to make sure all the plugs where connected. Checked out so i tried again same result. Dropped pan again tore apart v body, all valves moved freely. Hooked tech 2 up checked to make sure ps 3 was working and it was. Dropped pan and replaced the v body with one that was good. I'm still stuck in the same position. Im unsure where to even go next

PS sorry for the terrible introduction, my heads about to explode, My names Grant and have been working on custom vehicle builds for years and spent a lot of time working on chrysler transmission's.

 

[torqued2dmax]

Hello,
So I've been viewing these forums for awhile now and heavily reading all of Mike L's great advice. I've been messing around with these trucks for years and have finally ran into an issue i just cannot figure out. Saturday i changed Filters(internal and spin on) and put new fluid in. I drive a lot of miles over the course of a year so i do this every 15,000 miles or so. Never had an issue. Well after i went through my normal procedure and put it in drive for it to go into limp mode. I dropped the pan again, made sure i didnt damage the harness and checked to make sure all the plugs where connected. Checked out so i tried again same result. Dropped pan again tore apart v body, all valves moved freely. Hooked tech 2 up checked to make sure ps 3 was working and it was. Dropped pan and replaced the v body with one that was good. I'm still stuck in the same position. Im unsure where to even go next

PS sorry for the terrible introduction, my heads about to explode, My names Grant and have been working on custom vehicle builds for years and spent a lot of time working on chrysler transmission's.

How many miles ?

 

[juddski88]

Have you tried a different sump filter?

 

[GDduramax]

it has right around 360,000 miles on it. I tried a lot of things last night swapped an nsbu, try to disconnect all the plugs and plugged them back in. ran through the tech 2 and one weird thing i noticed is it wont let me do a quick relearn. im going to try to reset all the pressure tables today and see if that gives me anything. yes it has new wix sump filter.

 

[Chevy1925]

have you tested the solenoid or checked the wiring for it? does the wiring harness plug at the back of the trans (pass side at rear of trans) have trans fluid leaking into it?

 

[Mike L.]

'02 Allisons are not supported for a fast learn and, fast learn does not fix any problems.

 

[juddski88]

it has right around 360,000 miles on it. I tried a lot of things last night swapped an nsbu, try to disconnect all the plugs and plugged them back in. ran through the tech 2 and one weird thing i noticed is it wont let me do a quick relearn. im going to try to reset all the pressure tables today and see if that gives me anything. yes it has new wix sump filter.

I meant have you tried one that is not the first replacement you put in? I have had several filters come from the factory having leaks, and some have even been genuine Allison-branded filters.

 

[GDduramax]

First off I want to say thank you for all the advice. Had a crazy week at the shop and the truck got pushed off. I put a new filter on it today with no changes. Cleared all the tables and it started shifting. Needed parts for another vehicle so had to run about 80 miles to get them.
Shifted smooth and great...but transmission temp shot up. I guess I’ll rip the lines off and try to clean everything out real well. Never had good luck with this, seems in my case by the time the cooler lines have enough junk to get clogged, something else is wrong. I’ll hopefully update tomorrow and I believe my morning is pretty light. Once thanks everyone for help!