4l80 issues??? where to start??
4l80 issues??? where to start?? got a 2000 model 3500 chevy old body style
truck started having a small jumpy feeling when driving in any gear about a month ago. would do it sometimes when truck was cold, cleared up after a few miles
well today the problem got worse it is now doing hard shifts on all shifts 1-4
i don't drive the truck much trans is full of fluid, don't know when the fluid was changed last. only has 119k on it. fluid smells good an no check engine light
were is a good place to start on checking out what this problem could be?
truck started having a small jumpy feeling when driving in any gear about a month ago. would do it sometimes when truck was cold, cleared up after a few miles
well today the problem got worse it is now doing hard shifts on all shifts 1-4
i don't drive the truck much trans is full of fluid, don't know when the fluid was changed last. only has 119k on it. fluid smells good an no check engine light
were is a good place to start on checking out what this problem could be?
well drove it to gas station today an did fine other then shifting into OD was delayed, didn't want to shift till i let off the gas
ill get it scanned at Monday at a shop close by
anybody think it could be one of speed sensors on the side of the trans going bad?
Im a little lost on auto transmissions never really messed with um
ill get it scanned at Monday at a shop close by
anybody think it could be one of speed sensors on the side of the trans going bad?
Im a little lost on auto transmissions never really messed with um
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Hard shifts are often the result of the PCM commanding max line pressure, which in turn can be due to a engine bad sensor - MAF, TPS or MAP.
A simple check is to disconnect the MAF; the engine should still run just fine. You will get a check-engine light, but sometimes the trans then shifts correctly.
I do caution people not to go WOT with the MAF disconnected as the engine could then run lean and cause damage.
Might only be a 10% chance this is the cause, but very simple to check.
If you have a local trust-worthy trans shop or mechanic, have them hook up a good scanner which will show the commanded line pressure and any hidden codes.
A simple check is to disconnect the MAF; the engine should still run just fine. You will get a check-engine light, but sometimes the trans then shifts correctly.
I do caution people not to go WOT with the MAF disconnected as the engine could then run lean and cause damage.
Might only be a 10% chance this is the cause, but very simple to check.
If you have a local trust-worthy trans shop or mechanic, have them hook up a good scanner which will show the commanded line pressure and any hidden codes.
