Is my Tranny starting to go?
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Professional
Joined: Dec 2007
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Is my Tranny starting to go?
When driving the truck on the interstate (70 mph) and I get to a hill. Fist off, it seems to want to kick out of OD a lot more then any other vehicle I have owned. Then when the hill flattens and even starts to go DOWN hill it seems to take a couple of seconds for the OD to kick back in.
I can just push the "decel" button on the cruise and it will go into OD right away.
Probably nothing but just wanted to know if anyone else had a similar problem.
I can just push the "decel" button on the cruise and it will go into OD right away.
Probably nothing but just wanted to know if anyone else had a similar problem.
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Joined: Jul 2006
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From: Gainesville, Ga.
a bad throttle position sensor TPS can cause a lot of excessive downshifting. mine was doing that before i replaced it. its a lot better with a new one, about $40-50 at any parts store.
when it doesn't upshift, its related to the throttle and TV cable adjustment. i'd replace tps first and see if that fixes both problems. it could be a false problem where the cruise is just pushing the gas too hard.
when it doesn't upshift, its related to the throttle and TV cable adjustment. i'd replace tps first and see if that fixes both problems. it could be a false problem where the cruise is just pushing the gas too hard.
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Professional
Joined: Dec 2007
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yes this is with cruise on
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Thread Starter
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Professional
Joined: Dec 2007
Posts: 156
Likes: 1
a bad throttle position sensor TPS can cause a lot of excessive downshifting. mine was doing that before i replaced it. its a lot better with a new one, about $40-50 at any parts store.
when it doesn't upshift, its related to the throttle and TV cable adjustment. i'd replace tps first and see if that fixes both problems. it could be a false problem where the cruise is just pushing the gas too hard.
when it doesn't upshift, its related to the throttle and TV cable adjustment. i'd replace tps first and see if that fixes both problems. it could be a false problem where the cruise is just pushing the gas too hard.
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Joined: Dec 2007
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yes I do believe that I have the 3.55
Champion
Joined: Aug 2005
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check leaks in the vacuum system lines that feed cruise control under battery
if you can borrow a OBD scanner
look at the voltage signals for
TPS
MAP
for extreme 'jumping around'
while on cruise control,
then repeat using a 'smooth foot' on the accelerator pedal
instead of cruise control
(but the O2 sensor should jump around)
also check the accuracy of the speedometer
against either highway mileposts or GPS
because the cruise control computer programming does different things
depending on actual MPH
it is common for old/high mileage TPS to go bad at a certain spot in its range
good luck
if you can borrow a OBD scanner
look at the voltage signals for
TPS
MAP
for extreme 'jumping around'
while on cruise control,
then repeat using a 'smooth foot' on the accelerator pedal
instead of cruise control
(but the O2 sensor should jump around)
also check the accuracy of the speedometer
against either highway mileposts or GPS
because the cruise control computer programming does different things
depending on actual MPH
it is common for old/high mileage TPS to go bad at a certain spot in its range
good luck