$0E / $31 XDF Missing transmission parameters.

[1BadAction]

Did you use the pin X over I sent you ? Speedo seeing the correct signal ?

Just some thoughts

TOM

Yes, exactly, checked and double checked, doing it one pin at a time.

If I can find a $OE hack and have a minute I could likely find the tables and add them into the XDF. That being said I do not remember those tables being missing in the $0E .XDF I have.

I'm looking through the OE hack that I have, and I can't find any of these parameters referred to... But that doesn't mean they aren't in another hack somewhere. I appreciate the help.

[brian617]

Look under "4L80e Line Pressure Parameters" "Desired Shift Time Altitude Gain vs TPS vs Shift" is that it? Not sure what the Altitude Gain is for as the table just looks like TPS vs Shift to me.

[96lt4c4]

I don't think that's how the desired shift time works, as far as firming the shifts up. They way I understand it is, "desired" means the computer has to make the shift happen in the amount of time in this table to keep from throwing a code. If the shift does not happen in the desired amount of time then you get an error because the computer thinks the tranny is slipping. I may be wrong but that's how I thought it worked. There is nothing wrong with raising the line pressure to firm the shifts up. Thats what GM does in tow/haul mode in the newer trucks.

[1BadAction]

I don't think that's how the desired shift time works, as far as firming the shifts up. They way I understand it is, "desired" means the computer has to make the shift happen in the amount of time in this table to keep from throwing a code. If the shift does not happen in the desired amount of time then you get an error because the computer thinks the tranny is slipping. I may be wrong but that's how I thought it worked. There is nothing wrong with raising the line pressure to firm the shifts up. Thats what GM does in tow/haul mode in the newer trucks.

Desired shift time is just what it says. If the computer commands 800 millisecond shifts, it is slowing the shift down beyond what the trans is hydraulically capable of, and that makes the shifts feel like a slushbox. When you raise the pressure without cutting the shift time back, it is a firm shift, but its still slow. Just like the newer trucks in tow haul are, which BTW have a LONGER shift time along with the increased pressure.

The trick is to drop it to a reasonable level so 1-2 isn't violently snappy at low TPS, and use a bit of added shift pressure to firm it up.

[1BadAction]

Look under "4L80e Line Pressure Parameters" "Desired Shift Time Altitude Gain vs TPS vs Shift" is that it? Not sure what the Altitude Gain is for as the table just looks like TPS vs Shift to me.

it does, and I might just mess with that table alone and see how it works. 0D has both tables, so not sure whats up with it.

[Fast355]

Desired shift time is just what it says. If the computer commands 800 millisecond shifts, it is slowing the shift down beyond what the trans is hydraulically capable of, and that makes the shifts feel like a slushbox. When you raise the pressure without cutting the shift time back, it is a firm shift, but its still slow. Just like the newer trucks in tow haul are, which BTW have a LONGER shift time along with the increased pressure.

The trick is to drop it to a reasonable level so 1-2 isn't violently snappy at low TPS, and use a bit of added shift pressure to firm it up.

Not sure which vehicles are using longer commanded shift times in tow/haul. The 8.1 Express van tune my 4L85E tune is based off certainly does not. Commanded shift times were in the .3 or 300msec range. If you smack down on the throttle pedal a few times it can get to be a somewhat violent upshift. Using stock performance mode line pressure, commanded shift times, and 50% torque management reduction from stock it catches rubber going into 2nd at 50ish mph. 8.1 Van/Suburban Tow/Haul settings work pretty well on a 5.7 that makes more power than stock and hauls/tows a heavy load.

[1BadAction]

Not sure which vehicles are using longer commanded shift times in tow/haul. The 8.1 Express van tune my 4L85E tune is based off certainly does not. Commanded shift times were in the .3 or 300msec range. If you smack down on the throttle pedal a few times it can get to be a somewhat violent upshift. Using stock performance mode line pressure, commanded shift times, and 50% torque management reduction from stock it catches rubber going into 2nd at 50ish mph. 8.1 Van/Suburban Tow/Haul settings work pretty well on a 5.7 that makes more power than stock and hauls/tows a heavy load.

The 4L60 tunes in the half tons. 80E tunes are near perfect around 300 msecs, but the earlier 80s are near 800 + msecs.

[Fast355]

The 4L60 tunes in the half tons. 80E tunes are near perfect around 300 msecs, but the earlier 80s are near 800 + msecs.

That makes sense because even a good running 4.3 can kill the 60E!! 10 years ago I killed a 700r4 with a 2.8 TBI.

[Roadknee]

Desired shift time is just what it says. If the computer commands 800 millisecond shifts, it is slowing the shift down beyond what the trans is hydraulically capable of, and that makes the shifts feel like a slushbox. When you raise the pressure without cutting the shift time back, it is a firm shift, but its still slow. Just like the newer trucks in tow haul are, which BTW have a LONGER shift time along with the increased pressure.

The trick is to drop it to a reasonable level so 1-2 isn't violently snappy at low TPS, and use a bit of added shift pressure to firm it up.

I always thought the computer increased or decreased line pressure via the force motor to target the desired shift time (i.e. adaptive learning). If you can increase pressure but still maintain a slow shift time, what is the computer controlling within the transmission to achieve that desired shift time?

[1BadAction]

That makes sense because even a good running 4.3 can kill the 60E!! 10 years ago I killed a 700r4 with a 2.8 TBI.

LMFAO! Exactly. No love lost with me and 700 based transmissions. I had a "built" 60E shit the bed behind my otherwise stock 4.8 short cab stepside truck 7 months after I installed it. $2500 from an LS1tech sponsor right down the f'n drain.

[Nasty-Z]

Yes, exactly, checked and double checked, doing it one pin at a time.

Speedo seeing the correct signal ?

I had a "built" 60E shit the bed behind my otherwise stock 4.8 short cab stepside truck 7 months after I installed it. $2500 from an LS1tech sponsor right down the f'n drain.

Junk build , period.

I have been the bottom of the 10's with a very stout 700R4 behind a 496 BBC , absolutely no problems .

TOM

[1BadAction]

Speedo seeing the correct signal ?



Junk build , period.

I have been the bottom of the 10's with a very stout 700R4 behind a 496 BBC , absolutely no problems .

TOM

I tend to agree, it had Alto red eagles at 3-4, started to burn then a roller bearing came apart. Local trans shop put it back together with BW clutches and the same hard parts including the modded VB and pump. Ran like a raped ape after, but I never felt like I could trust it again long term. If I had it to do over I would have done an I-6 converter, servo and shift kit on a stock 60E and ran it another 100k miles.

[Fast355]

I tend to agree, it had Alto red eagles at 3-4, started to burn then a roller bearing came apart. Local trans shop put it back together with BW clutches and the same hard parts including the modded VB and pump. Ran like a raped ape after, but I never felt like I could trust it again long term. If I had it to do over I would have done an I-6 converter, servo and shift kit on a stock 60E and ran it another 100k miles.

I wouldn't even go that far with a 700r4 or 4L60E they are JUNK, PERIOD!!! I don't care how much money you spend in them they are still JUNK! I would rebuild a 4L60E by swapping a stock 4L80E into its place. I would trust a 4L80E I pulled out of the mud in the junkyard from a 200K mile work truck before I trusted any 4L60E.

[Nasty-Z]

I wouldn't even go that far with a 700r4 or 4L60E they are JUNK, PERIOD!!! I don't care how much money you spend in them they are still JUNK! I would rebuild a 4L60E by swapping a stock 4L80E into its place. I would trust a 4L80E I pulled out of the mud in the junkyard from a 200K mile work truck before I trusted any 4L60E.

You should tell us how you really feel Chris .......... LOL

TOM

[Fast355]

You should tell us how you really feel Chris .......... LOL

TOM

I have had about 7 different vehicles with them over the years and not a single one of them has survived more than 50K. The 97 Express van I have was my parents when it was new, the stock 4L60E didn't even make it 35,000 miles before it started hard shifting and setting the P1870 code. Ended up rebuilding it to 4L65E specs on their dime and it only lasted until 82K at which point it exploded an input sprag and drum.

I guess that was better than the 545RFEs in my Ram. I cooked one of those in 38K behind my 4.7 Ram, then behind the cammed Hemi I cooked one every 10-15K miles after that. One of them lasted about 3 days. The only one I had survive any length of time at all was a low mileage junkyard pull with a Transgo shift kit and a 30 psi line pressure resistor.