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kurt1993

01 Gmc 2500 Transmission Problem

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I have a 2001 Gmc Sierra 2500HD 4x4 w/ the 8.1L and Allison tranny it just rolled 50K miles and as i was plowing today i shifted as usual from forward to reverse when i was at a complete stop i herd a loud clunk (considering the transmission is silent when it usually shifts) and the truck jerked as it locked into reverse where it would usually just lock smoothly into reverse i finished up the plowing job taking it real easy but the truck would still clunk and jerk forward when shifted into drive and backward when shifted into reverse. I also noticed on the dash the little gear indicator would blink and not lock into a solid state unless it was in Park or 3 and my Service Engine Soon Light came on too.

 

I would like to know if i have any serious transmission issue or if its something more simple like a solenoid? do i need a complete rebuild or just something simple?

 

Thanks i would really appreciate any sort of helpful advise or answer

 

-Kurt

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I'm no expert on the Ally, but it sounds like a reverse pack or solenoid went. Stop by a parts store and have them pull the SES code.

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I have a 2001 Gmc Sierra 2500HD 4x4 w/ the 8.1L and Allison tranny it just rolled 50K miles and as i was plowing today i shifted as usual from forward to reverse when i was at a complete stop i herd a loud clunk (considering the transmission is silent when it usually shifts) and the truck jerked as it locked into reverse where it would usually just lock smoothly into reverse i finished up the plowing job taking it real easy but the truck would still clunk and jerk forward when shifted into drive and backward when shifted into reverse. I also noticed on the dash the little gear indicator would blink and not lock into a solid state unless it was in Park or 3 and my Service Engine Soon Light came on too.

 

I would like to know if i have any serious transmission issue or if its something more simple like a solenoid? do i need a complete rebuild or just something simple?

 

Thanks i would really appreciate any sort of helpful advise or answer

 

-Kurt

 

First thing to check is the neutral safety backup switch.

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First thing to check is the neutral safety backup switch.

 

X2.

 

DEWFPO

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First thing to check is the neutral safety backup switch.

 

X2.

 

DEWFPO

 

 

weird i didnt do anything and the day after i tried to drive it again but nothing went wrong... my dad said he went to advance auto and had the guy clear the codes and its been fine.... but is it really fine?

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First thing to check is the neutral safety backup switch.

 

X2.

 

DEWFPO

 

 

weird i didnt do anything and the day after i tried to drive it again but nothing went wrong... my dad said he went to advance auto and had the guy clear the codes and its been fine.... but is it really fine?

 

 

thats typical nsbu behavior when it starts geting bad. any chance the underside of the truck was wet when it acted up?

 

very common failure and a cheap fix...

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First thing to check is the neutral safety backup switch.

 

X2.

 

DEWFPO

 

 

weird i didnt do anything and the day after i tried to drive it again but nothing went wrong... my dad said he went to advance auto and had the guy clear the codes and its been fine.... but is it really fine?

 

 

thats typical nsbu behavior when it starts geting bad. any chance the underside of the truck was wet when it acted up?

 

very common failure and a cheap fix...

 

 

yeah i was plowing so it was real wet! lol thanks this is the kinda info i wanted to hear somthing that doesnt just have to do with codes... people never useto have codes to diagnose a problem anyway the codes are

 

P0700

 

P1713

 

P0700

 

the code PO700 appeared twice idk why?

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...... people never use to have codes to diagnose a problem anyway the codes are

 

P0700

 

P1713

 

P0700

 

the code PO700 appeared twice idk why?

Because vehicles didn't have all the electronic sensors and hardware like they do now....

 

Now you can think you have a trans problem when it is really related to a MAF sensor

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...... people never use to have codes to diagnose a problem anyway the codes are

 

P0700

 

P1713

 

P0700

 

the code PO700 appeared twice idk why?

Because vehicles didn't have all the electronic sensors and hardware like they do now....

 

Now you can think you have a trans problem when it is really related to a MAF sensor

 

 

dont know why the p0700 appeared twice, possibly 2 codes in the tcm(someone else will know)?? there are more codes to be read though, the p0700 is a generic code set as a result of a request of the tcm, need a different code reader to get the tcm codes, i dont know which readers read individual modules....

 

if memory serves, i think some trucks also had issues while plowing of getting snow/ice/water into the air intake and that set maf codes...

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Didn't know there were two posts in two different forums for the same truck with the same concern.

 

I replied in your other thread.

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we already fixed this for him in 2 other threads

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we already fixed this for him in 2 other threads

 

actually to be fair Rob your post was equally as good his just included the "wetness factor" and that the trucks left tire can kick stuff up right onto the censor which probably happened and im guessing thats why i had the problem i had cause all i needed was the codes cleared so far.... but i do still think im going to have a professional take a quick looksee

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Didn't know there were two posts in two different forums for the same truck with the same concern.

 

I replied in your other thread.

 

 

+1

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