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GPS Guru
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347 Posts
Discussion Starter #1
Here in the past few days my tranny has been shifting extremely weird. Sometimes it shifts hard, sometimes you can't even feel it, and unless I'm above 3/4 throttle, it'll shift into overdrive before I get to 30 mph, which I expected with big tires, but this is crazy... Anyway, what's the best way to go about it, get it rebuilt? new tranny? 4L80E maybe? :naughty: :superhack
 

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My name's not Kevin
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308 Posts
Sounds like it's in the valve body. I would take it to a trans shop and find out for sure. It's a lot cheaper to replace 1 part than the whole thing.
 

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03 Tahoe
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1,364 Posts
Did ya check the fluid? Sounds like it's dirty or has something in it (like clutch bits) hurting flow. You could do the 80...seems likes it's an easy deal but the harness's are different for the trans. If your 60 is going out get a nice performance built 60 and you'll be fine with that.

Cameron
 

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GPS Guru
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347 Posts
Discussion Starter #4
Haven't checked it, but it hasnt been but about 4k miles since I changed it. you're supposed to change it every 20k I believe? I'll go check it in a bit.
 

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Registered
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1,816 Posts
I'd have a tranny shop check out the valve body and solenoids, mine was doing even crazier stuff than what you described right after we had it flushed. Took it in, $100 and a couple of solenoids later, shifts perfectly. Havn't had a problem with it since, and that was 30,000 miles ago.

I don't know if you'd want a 4l80e, as far as I know they have different gear ratios in them to take advantage of the greater torque put out by the larger engines generally connected to that tranny.
 

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GMFS slowest truck :read:
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5,501 Posts
Whifflebat said:
I don't know if you'd want a 4l80e, as far as I know they have different gear ratios in them to take advantage of the greater torque put out by the larger engines generally connected to that tranny.
Yeah, with oversized tires, I don't think I would want the 4l80e, because first gear is only like 2.61 compared to somwhere over 3:1 with the 4l60e.
 
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