Allison malfunctioning

[solongpowerstroke]

I took my duramax to the store this morning, and when I got there and tried to back into a parking space, I noticed that I had no shift postion indicator. I counted clicks back to drive, and then I noticed that the indicator was flashing over the "3" and the service engine soon light was on. I found another parking spot and turned the truck off, waited a few moments, and then restarted it. Indicato was still flashing over "3". When I put the truck in reverse it engages very harshly, and also when I go to drive it engages harshly. Seems to operate normally going down the highway. Anyone else experience a problem like this?

[Dawg]

Search out or go back and look at the NSBU, Neutral Saftey Backup Switch, threads. Should answer your questions.

[SteveO]

solongpowerstroke,

The symptoms your describing sound like it's NSBU related..

I would poke my head under the truck and look to see if one of the connections to the NSBU have come unplugged or loose before condeming the switch.. If they are not loose, then the most likely problem is the switch..

If the truck has a Black NSBU, and it's out of warranty, I would replace it..
If at all possible replace it with a tan switch w/Shield, so far they have held up better than the Black ones..

Tan NSBU w/shield 29540479, you can buy them at any GM dealership or any Detroit Diesel-Allison Distributor same part number...about 50 bucks..

The guys (or myself) will give you a helping hand with the replacement process smile.gif if you need help...

Hope that helps..

Steve Overcash

[solongpowerstroke]

Dawg and SteveO, thanks for the info. After reading the threads, I decided that it had to be the NSBU switch. Called a couple of the local dealers today. First one told me the trans was junk, but he would sell me the switch if I insisted (for about 150 bucks)! Other dealers (or should I call them STEALERS like everyone else on this page does?)also quoted me 150 bucks. I bought the part at the local Allison dealer for $60. I guess I was reminded again why I hate to go to the dealer for anything. Took me about 20 minutes to change and everything is back to normal now. Thanks again.

[SteveO]

solongpowerstroke,

Great I'm glad you got it repaired..

$150 is probably about right if you add in labor + diagnostic time....

[Dawg]

I'm glad you got it fixed. This site is great. It sure makes me wonder how the stealer can tell you the tranny is junk. No wonder some get the reputation they do!

[FrozenAKJoe]

That's got to take the cake. $60 problem and the dealer says you're out a tranny. How much does an A-1000 cost out of the crate? I'm guessing at least $5-$8k. Unbelievable.

[SteveO]

FrozenAkJoe,

I have heard 5k installed from at least three dealers.. So far, all that I have witnessed replaced GM picked up the tab..

All have been replaced because GM (Truck Assmbly Plant) left the Torque Converter bolts loose, not installed, dropped one or two in converter housing, they all were leaking out the front...

solongpowertroke,

I heard $130 for a 29540479 (That's the Tan NSBU) at a GM Dealer..
If at all possible I would buy one from an Allison Distributor, they normally run $50-$60... Distributors are your Penn DDA, Covington DDA, Pacific DDA, Stewart-Stevens DDA, Williams etc... No way would I pay 130...........!!!

[ 01-02-2003: Message edited by: SteveO ]</p>