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Old 03-28-2008, 04:01 AM   #1
Flingarrows
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4L80E downshifting
I am asking this for a guy from work, who is a good mechanic on the older engines and transmissions, but doesnt work on the newer equipment.

he owns a 95 chevy 3500 dump truck with an auto which he says is a 700r4, electronically controlled. Ive been told by someone else, that is actually a 4L80E

intermittently the tach and speedo go dead and the trans down shifts, and wont shift up. he says that it only happens when warm.

any ideas? what additional information should i ask for?


If this is in the wrong forum, just let me know, I'll delete and repost in the proper place

Last edited by Flingarrows : 03-28-2008 at 04:03 AM.
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Old 03-28-2008, 01:09 PM   #2
NEUMANNZZ
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Re: 4L80E downshifting
might be the vss or wiring in the tailshaft housing.
O2 GMC RCSB 4.8L V8 AUTO 3.73's
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Old 03-28-2008, 10:47 PM   #3
young blood
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Re: 4L80E downshifting
we just had a truck at work do this it was the vss sensor put a new one on and bam it works great
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Old 03-29-2008, 05:30 AM   #4
Flingarrows
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Re: 4L80E downshifting
thanks guys, i'll pass it along


anyone else?
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Old 05-13-2008, 03:53 AM   #5
Flingarrows
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Re: 4L80E downshifting
update.. it turn out to be the ignition switch putting out intermittent voltage to a sensor on the trans
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