Hi, I am new to this forum and would like to say thanks in advance for any answers. I have a 2001 GMC with a Duramax and Allison trans. I went out the other morning to do some snow plowing and found I have no reverse. I looked on this site for other post, but didn't quite find what I was looking for. Just wondering if anyone here might know whats up with this (I know it could be a number of things)? I am thinking maybe a bad sensor or somehting. The local transmission shop has the truck now, and the only thing they are telling me is that it is showing 4 different codes, but I don't know which ones. Is this a common problem with this trans? I have had no other problems in the past. Truck has 65000 miles on it. Any comments are apprieciated. Thanks for your time.............James
allison trans no reverse?
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Thats a pretty quick conclusion to jump to, though I suppose it could be.
Have you checked the obvious-fluid level? The spin on filter should be changed at least every 25k miles, has that ever been changed? Also, the NSBU-neutral safety backup switch is a common failure on these trucks.
Do you have any power-adder chips? Fill out your signature so everyone knows what you drive.
Have you checked the obvious-fluid level? The spin on filter should be changed at least every 25k miles, has that ever been changed? Also, the NSBU-neutral safety backup switch is a common failure on these trucks.
Do you have any power-adder chips? Fill out your signature so everyone knows what you drive.
Well the guy from the trans shop called back and said it needs $1500.00 in parts, plus a $1000.00 Labor. I can see the $1000.00 in labor to pull it and go through it, but I am wondering what the $1500.00 in parts are. I only talked to him on the phone and have to go up there to go through this with him, he says it needs upgrades because it's the early model of the transmission. Does this sound right to you? He hasn't given me the codes yet and they already pulled the trans (which I didn't know they were going to do). I am very courious to what they say. They are the only trans shop within 50 miles of here, and I have never heard anything bad about them. Out of couriosity called two other trans places (over 50 miles from here) and they said it usually is switch or electrical problem and they seldom need to pull the trans. By the way, this same shop changed the trans fluid 3 months ago, and everything was fine then, I hope they didn't put the wrong fluid in it.
Well I guess I'll have to wait to see what the guy says. Thanks again for the comments........James
Well I guess I'll have to wait to see what the guy says. Thanks again for the comments........James
Hi Mike, Why do you think it will do the same thing after they rebuild it? I would hope they put a new NSBU switch on it, but would not be happy if that was all it needed and they rebuilt it anyway. I value the opinions of you guys, the guy at the trans shop said they don't have much experience with the allison transmissions (not very reassuring). Thanks...........James
The first move on their part should have been to read the codes then look them up. If they could not understand the code explanation they should then call someone. Next move should have been a new NSBU switch as it is cheaper to replace than diagnose and you probably need one anyway. Since they allready have the Alli apart you should upgrade the parts and converter.86 mc;1560931; said:
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