4L60e issues,...bout to take a 50cal and give er the whole 9 yards

[Hutchinson]

Thanks JasonB, I truly appreciate your time in trying teach me the wonderful world of transmission tuning. I'd bet a lot of new people (and experienced users) are reading this thread and learning lots from you. I'm kinda busy today bud, my wife has relatives coming in from Malaysia to visit/stay with us for a few days,....have to show them the central Florida saltwater redneck lifestyle for a few days,....switch hats and become an entertainer,.....oh goody.

I'll go over your writing above sometime this evening or tomorrow morning with my morning coffee. Thanks again man, truly appreciated.

[Jason B]

I dpn't really jack with the line pressure settings all that much. Keep in mind maximum line pressure is controlled mechanically. I do up the pressure enough to make sure the engagement is not slippery but the first 60E died on the stock tune.

Have fun. I'll be doing the same down here on the blistering hot treasure coast of fl.

[Fast4.7]

What died on it?

Input Shaft/Drum on the stock one at 38K. The case failed on the 2nd one. Stripped the case lugs right off the clutch pack.

[Jason B]

Input Shaft/Drum on the stock one at 38K. The case failed on the 2nd one. Stripped the case lugs right off the clutch pack.

A 4L60E? Stripped the low/reverse lugs out of the case? They are the only lugs in the case. I don't believe that's possible. I don't believe you have pictures of that. Doubt anyone does.

[Fast4.7]

A 4L60E? Stripped the low/reverse lugs out of the case? They are the only lugs in the case. I don't believe that's possible. I don't believe you have pictures of that. Doubt anyone does.

I have them on my photobucket account, but because of their sudden policy change I refuse to pay photobucket a dime so that I can host them on another site.

It was a forced WOT 2-1 manual downshift about 25 mph that broke it. Sounded like the jolly green giant unzipped his zipper. I was pulling out onto the service road, a car that was hauling butt (60+ mph) changed lanes into my lane about 100 yards beside me in the middle of me making a right turn onto the road, put my foot on the floor and threw the shifter into first to jump across the other lane and out of the path of the idiot. It still took off and went but the top half of the low/reverse case lugs all sheared off. Was only a ~350 hp 350 making about 400 tq in a 6,200 lbs Express van, ZERO'd torque management.

I would gladly email or otherwise send the picture I have of the carnage of the case.

EDIT--- I will also say it was not a snap ring related failure either. The snap ring was still securely in its groove just the case lugs under it ceased to exist as a portion of the case.

[Jason B]

Attachment 72033
I've had this picture for a while, not sure where it came from. I'd guess this isn't yours. These case lugs aren't what I'd call sheared

[Hutchinson]

Dammit man!!! Now thaaaaatttt'sss a carnage pic there now,...... simply badass,..... I keep going back to look at it again and again,,....hope I never see any of my stuff look like that.

Wow,...yeah, I just looked at the pic again.

[Fast4.7]

Attachment 72033
I've had this picture for a while, not sure where it came from. I'd guess this isn't yours. These case lugs aren't what I'd call sheared

Looks like a drum explosion there.

I put a junkyard 4L85E from am Express van in my Express van to fix my 4L60E. I slapped a Transgo HD2 shift kit in it and a deep pan on it and have run it relatively trouble free since 2013. The junkyard 85E had 110K on it, has over 150K on it now. Still chirps the tires going into 2nd at 40 mph. 30" tall tire and 4.56 gears with a Yukon Duragrip posi.

[Hutchinson]

How you like those Yukon parts Fast4.7? I put a Detroit Helical locker in mine,...but everything else was new Yukon stuff (ring and pinion, rebuild kit, axles, etc).

I must say, that Detroit Helical romps those 35" BFG All Terrains without hesitation,...both black streaks are identical, starting at exactly the same time,.....straight-lines down the road.

[Fast4.7]

How you like those Yukon parts Fast4.7? I put a Detroit Helical locker in mine,...but everything else was new Yukon stuff (ring and pinion, rebuild kit, axles, etc).

I must say, that Detroit Helical romps those 35" BFG All Terrains without hesitation,...both black streaks are identical, starting at exactly the same time,.....straight-lines down the road.

I have had the Yukon stuff in about 6 months, probably 6K. I work in the parts dept of a Nissan dealership. I set it up at work on a lift on a Sunday. I also did the burnout test and it works perfectly. My WOT jab resulted in 2 black marks about 30 ft long from the P275s on it. It is smooth around corners too even under throttle.

My buddy at work just put a Lunati Hotcammed 350 Vortec in his 1998 mudtruck Tahoe on 35s. His 3.73 rear-end died the next day. After alot of persistance to talk him out of 4.10s he put the Duragrip and 5.13s in the truck. He is still breaking in the gears but the Tahoe runs great. Only issue I have not had time to mess with is an ABS code for speed sensor mismatch. I have fixed 0411s but not have not had the time to mess with his black box setup again. I used BlueCats to setup the shifting and the PCM has the speedo perfect after the tune compared to GPS. It leaps off the line and pulls like a monster even at 1/2 throttle. Will do a standing burnout on dry pavement merely standing on the throttle. 2,400 rpm at 70 mph is the PERFECT cruising RPM for the 350 with the 218/228 cam in it. He has a Volant CAI modified slightly for the 3" body lift and shorty headers with 2.5" pipes to a dual in/single out flowmaster.

[Fast4.7]

And yes his torque management is setup the way I do all the 4L60Es I tune. It is stock line pressure except zeroing out the negative values in the compensation tables. 0.300 msec command shifts at 40% torque reduction under load. Has a crisp shift without being overly harsh.

[Fast4.7]

Compared to the high mileage stock cam 350 and 3.73s on the stock tune the truck is a rocket everywhere.

[Hutchinson]

Yeah Fast4.7, I plan to change my gearing when I rebuild the front differential. I haven't decided what to go with yet,....I'll run the math --- (new tire size divided over old tire size) x stock gear ratio = new gear ratio. It'll get you close to original drivetrain duty load. I don't remember what the 96 GMC 4x4 stock tire size was,...or I would run the calculation right now,....I'll have to look it up.

Only two things that haven't been rebuilt/changed on the entire truck is my xfer case and the front diff,....which will come shortly. Right now, my rear has the 3.73 (as it was stock).

[Hutchinson]

I believe the truck came with P245/75/R16 stock sized tires,....meaning they were 30.5" tall.

Above math would run out at -- 34.5/30.5 x 3.73 = 4.23 gear size change

Meaning 4.11's or 4.27's would be the go,......with 4.11's giving me a hair better gas mileage (over the 4.27's).

Whatcha think? Does this sound bout right?

Also, I found a chart this morning referencing gear/tire size that may help someone in the future;

IMG_0369.JPG

[Fast4.7]

I believe the truck came with P245/75/R16 stock sized tires,....meaning they were 30.5" tall.

Above math would run out at -- 34.5/30.5 x 3.73 = 4.23 gear size change

Meaning 4.11's or 4.27's would be the go,......with 4.11's giving me a hair better gas mileage (over the 4.27's).

Whatcha think? Does this sound bout right?

Also, I found a chart this morning referencing gear/tire size that may help someone in the future;

IMG_0369.JPG

That chart is true for a trans with a 1:1 high hear. You are dealing with a trans that has a 0.70:1 overdrive. For my buddies truck that 3,200 rpm becomes 2,250 rpm. I would stay somewhere in the 2,200-2,600 rpm range at 70 mph in OD. That is where my small blocks have liked turning. When you get down in the 2,000 and lower rpm range it puts alot of load on the engine and you will actually get worse MPG.

[Fast4.7]

Per the tire manufacturer my buddies 35" tall tires were 576 revs/mile. With a 5.13 gear that is just over 2,900 rpm at the output shaft of the trans. In OD that is just over 2,000 rpm @ 60 mph. His truck loves the 5.13s.

[Hutchinson]

Thanks Fast4.7,...sounds like you gotte'r figured out,....I've just always done the gear size math the easy/lazy way I guess. I never got into revs per mile or anything like that. I was simply looking at returning the truck back to a somewhat stock base drivetrain load/rpm due to putting larger tires on.

I'd imagine with 5.13's,...that truck is like a rocket ship. Bet it'll snatch the teeth fillings out of your head on a snappy 2nd gear catch (manual trans that is). My truck is simply a daily driver though,...which I'm simply trying to maximize durability while still having some decent haul tater.

I agree, my truck lumbers a bit at highway speeds below 2Krpm's, so increasing gear sizes should raise the rpm a bit. We'll see when I get to that point in a couple months. I may go larger than the 4.11,....

[Hutchinson]

Well fellars,....finally got some time yesterday to properly scan my trans and start implementing y'all's advice,....tune tinkering time,.....gotta few hours before the NASCAR race/beer time today,......here's what I've got/plan to change today;

--Shift Time--
"Time of Latest Shift" PID shows slow shifts (2.5 to 3.9seconds) on the 1>2 and 2>3 shifts. My 3-4 shift is perfect at .2-.3 seconds (as it should).
==I'm gonna zero out the entire desired shift time vs torque table to see how it acts.

--Spark advance reduction after each shift--
Scan showed a spark advance drop right after each shift happens,...in the magnitude of ~ 34 down to 24 (just using numbers),....which creates a lag in power right after the shift, even though my rpm/throttle % stayed same.
==I'm gonna start with zeroing Abuse mode, then zeroing Trans TM, then move to Engine TM,...per y'all's recommendations. I gonna try to eliminate all of this spark reduction, just to see how it acts, then adjust/fine tune back up from there as needed.

--Trans Pressure Adjustments--
Upshift Line Base Pressure Normal Table - change to 90 psi from 240 to 640 then "Interpolate between Horizontal Lines" from 100 to 240.

Then implement y'all's advice on zeroing out the Upshift Pressure Multiplier vs Trans Temp vs Gear table. See how it acts, then, make slight changes in the 1->2, 2->3, 3->4 Upshift Pressure Modifier vs Trans Temp vs Torque tables to fine tune (someone also recommended zeroing this out as well,...whatchall think?).

After changing each item above, I'll drive/scan and see how it acts. Have I laid out the steps correctly above? Meaning, would y'all do things in a different order,...like do the pressures before the shift times/address spark reduction, etc?..

My TCC works perfectly,....a little bump, letting you know it engaged, but no harder than any shift. TCC table settings are min 90/max 100. And engages perfectly per the speed/TPS table. My normal Upshift/downshift speeds/TPS are dead on too.

Thanks fellars,....I'll let you know how it fairs out.

[Hutchinson]

Well guys, got all my test tunes set up to run. Gonna upload first tune listed below, then drive, then upload next tune, then drive,...etc. all the while scanning for desired results on how those changes affected drivability/performance. Each tune "step" below will have all the previously made changes included, thus, I can tell how they work/interact,....individually, and as I go through them all (accumulative). i.e. 6.6 will have all the changes made from 6.5, 6.4, and 6.3

I decided to address the Spark Retard first, then main shift tables, then pressure multipliers/modifiers.

Tune #
6.3 - Zeroed Trans TM and Abuse Tables - has no transmission TM
6.4 - Engine side of TM - Zeroed Spark Retard vs Torque Reduction table
6.5 - Zeroed both Normal and Performance Shift Time Tables - Desired Shift Time vs Torque Tables
6.6 - Adjusted Upshift Line Pressure Normal and Performance tables - 90psi from 240TQ up, and then interpolated between horizontal lines between 0-240TQ
6.7 - Zeroed Upshift Pressure Multiplier Table
6.8 - Zeroed Upshift Pressure Modifier 1>2, 2>3, 3>4 tables

Per 6.7 above - Should the Trans>Auto Shift Properties>Shift Pressure>Shift Pressure Modifier>Pressure Multiplier table be set to "1" in all table cells, instead of zero? Reason I ask, last part of the table description says Increasing the Multiplier firms the shift. 1 = No Change.

Do the above steps in tune changes make sense? Or should I do one, before I do another?

Almost seems like I'm taking this 4L60e back to the stone age,......

Thanks Fellars

[Fast4.7]

Well guys, got all my test tunes set up to run. Gonna upload first tune listed below, then drive, then upload next tune, then drive,...etc. all the while scanning for desired results on how those changes affected drivability/performance. Each tune "step" below will have all the previously made changes included, thus, I can tell how they work/interact,....individually, and as I go through them all (accumulative). i.e. 6.6 will have all the changes made from 6.5, 6.4, and 6.3

I decided to address the Spark Retard first, then main shift tables, then pressure multipliers/modifiers.

Tune #
6.3 - Zeroed Trans TM and Abuse Tables - has no transmission TM
6.4 - Engine side of TM - Zeroed Spark Retard vs Torque Reduction table
6.5 - Zeroed both Normal and Performance Shift Time Tables - Desired Shift Time vs Torque Tables
6.6 - Adjusted Upshift Line Pressure Normal and Performance tables - 90psi from 240TQ up, and then interpolated between horizontal lines between 0-240TQ
6.7 - Zeroed Upshift Pressure Multiplier Table
6.8 - Zeroed Upshift Pressure Modifier 1>2, 2>3, 3>4 tables

Per 6.7 above - Should the Trans>Auto Shift Properties>Shift Pressure>Shift Pressure Modifier>Pressure Multiplier table be set to "1" in all table cells, instead of zero? Reason I ask, last part of the table description says Increasing the Multiplier firms the shift. 1 = No Change.

Do the above steps in tune changes make sense? Or should I do one, before I do another?

Almost seems like I'm taking this 4L60e back to the stone age,......

Thanks Fellars

I personally would not do anything to lessen the torque management on that combination, if anything add extra in. Then reduce the commanded shift times, but certainly not much less than 0.250 msec on a 4L60E. You are just asking to break something tuning it like that, IMO.

As for your previous post on the timing dropping from 34 to 24* after the shift. The torque management spark reduction is only in effect for the length of the shift time. If the timing is dropping below the timing map it is most likely torque limits that are being reached and the PCM pulling timing for those.