2004 truck 4l60e

[COWLGMC]

In 10k miles I have burnt up 3rd and 4th bands in a new tranny twice now!Im at work or I would post my tune...later today I will.Anybody else had this problem.The truck is lightly modded but I wouldnt think Im overpowering the tranny......Any ideas or even an educated guess?

[jimmyblue]

If you are really "burning" frictions I think this is a
line pressure problem, and probably coming from the
commanded line vs load (shift or steady). If you break
stuff you have too much torque or too much pressure
(shock breaks things) and if you burn it you have too
little.

Things that corrupt the airflow reading fidelity get
right into the torque computation and from there
into the line pressure. K&N, descreened MAF in a
bent inlet tract, shitty stock line/load profiles (you
can't do much about that except jack around the
force motor table if your model doesn't have the
General Pressure tables accessible) and stuff like
that.

If you understand the failure mode maybe it will
put you onto something. But you may have to
really probe whoever disassembled the last one, and
make sure they understand what they're saying (not
just blabbering something they overheard on the
shop floor).

[COWLGMC]

I attached my tune to the first post....look at torque management....4136947 ft lbs is probably messing with calibration Russ..any ideas.I have seen your post on tranny stuff

[gman4dx266]

Check out some of Russ K's transmission pressure settings. Its an easy fix to do to your pressures and you're all set. Basically it makes your pressure increase X for Y torque. Your pressure table will naturally max out @ 96psi in the uberhigh tq colums and will be tolerable in the grandma-driving cells. lol

Also (i didnt look at your tune yet) you might want to stick some transmission torque management in there, just enough to cushion the blow. Also, it would help a bit to draw out the converter settings(add some slip if you want) so that its not a harsh shift. That is up to you though. I went through a 4L60-E in approximately 7100 miles. Same thing happend as yours; burnt up all the clutches/bands and cracked a plastic apply piston. Of course being the original transmission (read: the truck also had 7100 miles in it) GM replaced it under warranty.

[COWLGMC]

Thanks for the input gentlemen.I need to completely redo my trans settings so this doesnt happen again....my dealer is startin to give me that look when I come in

[COWLGMC]

Sure enough...I uped the pressure by 10 accross the scale and wow!what a differance!My tranny guy told me to keep the pressure low to save the pump,but I think I was too cautious.Im going to check out RussK tables for more help....thanks again

[Russ K]

Post your stock tune, as the 04 Sierra file I have has a lot of differences in the trans tables. And zeroing out the upshift torque reduction tables on a stock 4L60E is the best way to destroy it!

Russ Kemp

[COWLGMC]

Sorry Russ...I lost my stock tune when my laptop was stolen last year.This is my most recent and 1st tune

[Russ K]

COWLGMC,

Try this trans tune. A Corvette 2-4 servo would really firm up the 1-2 shift at wot. What mods are done to the engine, as your WOT shift rpm is very high if your cam & valve springs are stock. You have way too much spark timing, I would drop the wot timing to 24*.

This tune is based on the first one you posted.

Russ Kemp

[COWLGMC]

Thanks for the help russ...can I just copy and paste the tables to any of my tunes?(trans that is)

[Russ K]

No, that is your tune. Just do a normal write calibration.

Russ Kemp

[COWLGMC]

Russ,thanks so much for taking the time to help.I know your swamped with questions on a daily basis The tune you looked at was completley maxed out...trying the limits...Can i apply what you did to my detuned tune?

[COWLGMC]

OK Russ...applied your trans settings to my latest tune and seems to be pretty smooth.Could be firmer on 1-2 shift but its real predictable in the way it shifts.Ill try to log some data and post tommorow.

[hog]

Post your stock tune, as the 04 Sierra file I have has a lot of differences in the trans tables. And zeroing out the upshift torque reduction tables on a stock 4L60E is the best way to destroy it!

Russ Kemp

The 700r4 shifted at WOT with no kind of TM. I have disabled my TM 100% and have manymiles on it.

peace
Hog

[Russ K]

Yes, on the 1996-2000 Vortec trucks I zero the torque management. These trans can be set up to shift very firm at wot. The 4L60E trans in the 5.3 & 6.0 trucks, and the 5.7 F-body vehicles can have the upshift torque reduction reduced by 50%.

These vehicles need the Corvette 2- servo installed in order to get the 1-2 shift firm enough so that you can zero the upshift torque reduction. I've maxed the 1-2 shift pressure table & zeroed the force motor table at the 96 & 100 psi columns, yet the wot 1-2 shift still slips a bit when the upshift torque reduction is zeroed.

The 4L80E trans can be tuned to shift firm enough that I can zero the upshift torque reduction with out a problem.

Russ Kemp

[FlaBouy]

My 6000# leadsled has had zero TM since September 2005. My 4L60E has 60,000 miles on it and is stock save the vette servo and HD2 shift kit with 2 washers. After 19 months of FI, and current 525 RWHP (15 months) the 4L60E is holding up pretty well spinning 305/50/20's with 3.73's. I think Russ K has hit it on the head with the line pressures. Most guys try to use line pressure to soften the shifts or take load off the pump. Your pump survives while everything else scatters.....

[COWLGMC]

Im putting a 4.30 rear end in next weekend.I have heard that this will take some load off of the tranny as well.A buddy has 4.10s in his truck and it seems to run effortlessly compared to my truck with a 3.42

[gman4dx266]

Im putting a 4.30 rear end in next weekend

Forget driving on the interstate