I'm at my wits end with these F*ing automatics (I hate them! POS never does what I want/when I want)! I can't wait till winter holiday to do my t56 swap!

I have lowered line pressures, added time to the shift table, and nothing seems to help (I even tried zeroing the entire pressure table and setting the time to 5seconds...didn't notice a bit of change). My low speed 1-2 shift kicks so hard the whole truck bucks and it's really shitty to ride in. 2-3 and 3-4 are "ok" but still could be a bit softer.

Could someone please take a look at this file and see if I'm missing something? On "normal" starts (just daily driving), I'm seeing (in the scanner) in the range of 150-180ft/lbs of "Delivered Engine Torque" on 1-2. 2-3 and 3-4 are about 100-150ft/lbs.

Stock Tranny/Converter, cam, etc. Only thing different is 4.56gears but they shouldn't make a difference.

 

Mine was shifting really hard for a long time and I never adjusted it. I suspect that is how I broke my 4.11 gears. It wouldn't chirp until i took my grippy 20"s off and put weak *** used 17"s on. So I assume the fact that it was getting grip while shifting hard is what did them in. Found out that I was also blowing fluid out of the overflow tube.

Mine shifts cruising throttle at about 164ftlbs, 200 with a lil more, and 320at WOT.

I'm using EFI and can't see your file but here is where I started and ended.
Started here:


Ended Here:


Now it shifts nice and solid in every gear without being harsh. With Tow Haul on you notice a nice little improvement without going overkill. (depending on tires).

 

My experience has been that if the tranny is setup mechanically for extreme firm shifts, tuning will do little to tame it down. I reverted to short shifting 1st gear under low throttle/slow speeds with a couple of my built 60e's because of violent 1-2 shifts, after spending considerable time trying the same things in the tune you are to no avail.

 

^^^ nailed it ^^^

You have a shift kit? What stage?

 

have you tried stock trans settings?

 

It's a 100% stock tranny (no shift kit, no converter). I tried the stock settings and there were just as violent. As I said, in attempt to see SOMETHING change I even went so far as to put the pressure table to 0 EVERYWHERE and the shift time to 5 seconds (5.000 vs stock of about 0.600) yet I didn't feel any change.

Are these trannys just "hard shifters" from the factory? Even the one in my Tahoe feels harsh. I notice other cars/trucks with 4L60s (ex: escalades, caddy cars, even f-bodies) don't seem this "harsh".

 

There are some conditions in which the tranny will be set to "limp" mode and result in 100% line pressures at all times. Any stored DTC's for the tranny?

The tranny could be hurt. Broken accum springs or the like.

 

did you change the just the pressure settings or allof the trans settings?Reason i ask is it looks like your locking the converter up in 2nd gear.

Has it always shifted hard or did it just start doing this??

 

That is definately strange. I have never seen any of the trucks have any kind of harsh firm shift at all in stock form with all of the trans settings set to the factory settings usually it is the exact opposite for the trucks especially where the shifts are pretty soft and sloppy that's why I recommend to people to at least get the corvette servos.


It acts like this with ALL of the trans settings set to stock?

 

Its those 4.56's.
It does shift hard though, thats why i asked if you had a shift kit that day i rode in it.

I thin you have a freak transmission, my truck feels nothing like yours, and we have close to the same mods, you just have a really steep gear