Allison troubles

[Dazedandconfused]

I'm posting this for another guy that is having problems with his truck so any help would be great.

Trying to diag. some issues. It throw's code 0500, 700 and 721 but the trans is fine until it randomly goes into limp mode. It goes into limp mode and the speedo goes nuts, the brake LIGHTS come on and off. Do I need this NUBU (or something like that I've heard people talk about) part you all are talking about? I can reset my codes and the truck is fine, then randomly it just does this all over again? I can turn the truck off and back on and limp mode goes away. But the check engine light stays on. It also did the range shift inhibit thing when pulling up in the driveway this AM? Then I went back to P and into D and it went away? The trans pulls too good and shifts to smooth to be bad, whats up

 

[stroke250]

t-case issue?? what year is the truck??? mileage??

 

[SmokeShow]

04.5 lly, low mileage...

 

[THEFERMANATOR]

P0500 and P0721 are both for output speed sensor, and P0700 is simply a TCM DTC is present which a problem with the output speed sensor would trip. Check the output shaft on the transfer case for slack if it's a 4X4, and check the connections on the speed sensor.

 

[moorekh]

First off it is my truck they are talking about! I'm new to the dura scene and it hasn't been the best week of truck ownership after finding out what all this truck needs in preventitive parts/tricks. I'm having issues like the above states. Hoping my $150 in electrical parts and shipping fixes this! I ordered a NSBU switch and a rear speed sensor from Merchant Auto yesterday and it should be here today. Nick @ Merchant said he was 99.9% sure this would fix my problems. I'm PRAYING it does fix it! I've also got a pump rub kit fix ordered that a buddy and I are going to try and tackle We are both somewhat mechanically inclinded so we should be ok.

A big thanks to Andy and Mitch for getting this thread going and helping a newby to the Dura world out! Mitch I know we've PM'd a bunch over on KYDTR and whenever the part comes in let me know! I have NO idea who tuned the truck either, the guy who supposedly did, didn't

 

[SmokeShow]

No big deal. We'll get ya squared away. :thumb:

 

[ynotracing2221]

Sounds like you have some good guys helping you out. Let us know how everything turn out for you. Good Luck! :thumb:

 

[Dazedandconfused]

No problem Kyle that is what its all about. Hope you get it fixed they really are nice trucks.

 

[moorekh]

Yeah, I LOVED my 04 6.0 gas truck, it never gave me a minutes trouble! This one just may need some common fixes. I know on my 2nd gen Dodge nickle and dimed me to death! I really dont wanna go through that again. The Chevy is ABOVE and BEYOND a better shell and trans. I'm not convinced on the motor yet Time can change that though!

 

[moorekh]

Got the parts in today and will have it done tonight. I checked my xfercase last night and it was NASTY, it was a silver color??? Is that normal? There was nothing bigger than tiny tiny shavings on the speed sensor and the shaft didn't show(feel) any wear. What drained out of the case was just liquid and a tiny partical here and there. What I did find made me quite mad. The truck has a transmission brace and whoever did it just let the wire loom of wires hang down. They broke the factory tabs and just threw the harness on top of the trans! When I crawed under the truck guess where they were resting on? You guessed it! The front driveshaft! None of the wires seem to be hurt and luckly they were all in the loom still. I re-taped them and zip tied them back away from any moving parts. I'd almost say the NSBU and speed sensors are not bad and it was just getting bad signals from the lines rubbing and banging on the front drivshaft! I'll know tonight I guess! Good news is I have no pump-rub issues and the front and rear diff's looked great when I checked them!

 

[moorekh]

got the NSBU and rear speed sensor in tonight in under 20 mins. It was super easy and seems to have fixed my problem :thumb: I put about 25 miles on it and I'm really starting to like this truck

 

[SmokeShow]

Good to hear bud!

 

[ynotracing2221]

Good Job! Glad to hear you got it fixed! :thumb::thumb:

 

[rtcook]

I don't think you'll be dissappointed.

I put about 25 miles on it and I'm really starting to like this truck

 

[Dazedandconfused]

Glad to see its acting ok now Kyle. Hey what do you know Todd's on here as well.

 

[rtcook]

I lost my password for a long time and just now decided to get a new one. I usually just read, I don't want to feel like a dumbass asking questions.

 

[moorekh]

Yeah, I liked driving it last night so much I drove it to work today! If you know me and trucks I take very good care of them and since I work at a Power Plant I wash them (my trucks) everytime I drive one on site cause of the mist that comes out of the cooling towers makes SUPER hard water spots and kills paint jobs. I drive a little Civic everyday but today I had to show the Dura to the world!