Hey guys, I've just got a 3k rpm converter installed, and when I'm on the interstate locked in 4th gear, if I let off the gas, the converter unlocks, then when I get on the gas again it'll shoot up to 3000 then lockup again, very annoying. I read somewhere that this is normal on the 4L80 tranny, can this be corrected in the tune on the 4L60 trans?

Keith

 

i believe it is normal b/c my stock verter does the same thing. But, you may be able to tune for this. May want to send an email to Justin

 

my stock converter stays locked in when on the highway/interstate. causes my truck to slow down and exhaust to cackle a little...maybe there's something wrong with mine???

 

Just found an answer to this...you have perform an f-body 4l60 segment swap into the tcm to eliminate the unlock when coasting. Wanted to share this info incase anyone else finds this annoying.

 

Im not very sure how the engine/truck would recover very well after losing speed/rpm and the converter stayed locked. I would think the engine would lug badly causing another driving annoyance... I guess give it a try and see how it works

 

Do it & post up. I agree that it gets annoying, especially in traffic when I'm on & off the throttle repeatedly.

 

My truck does the same thing and is really noticeable when towing in OD. I find that if we leave it in 3rd while towing its better but the fuel mileage suffers a bit. Its all factory with a stock converter so with a 60 this is normal. With a high stall you would most certainly want to have your tune adjusted if possible to correct this or install a toggle switch in the LU circuit to keep the converter locked.

 

I don't have efi live or hp tuners, but will be purchasing either soon. I don't think the engine will lug excessively as long as I don't slow down to below 60 mph, its just for the on/off, on/off type driving you do in traffic on the interstate. If the engine does lug, just give it a tad more throttle and the converter should unlock for ya and prevent lugging


If i'm in town or on highways, I usually leave the shifter in 3rd to allow lockup before 45 mph. I want to redo my shifting to not allow 4th gear until speed is greater than 55, otherwise stay in 3rd and lockup at 35 or greater if throttle permits. I wish EFI live wasn't so expensive, just bought a tvs 1900 so I gotta save up some more $$$ lol