Transmission Shift Woes

[1badc10]

I have the following:

'86 Silverado C10
5.3L V8 (Comp 224 cam, Comp 7.400 p-rods, Comp 918 springs, UDP)
4L60E (Transgo SK-4L60E shift kit, PTC3000 converter)
4.10 rear w/ GM POSI <--- I LOVE THAT THING!

After the first trans (stock) went belly-up after 2500 miles (no forward gears & spun bearings & bad pump), I bought a rebuilt unit (cheap). Since then, the rebuilt unit has cost me $400 b/c the 3/4 clutches went South (new clutches & shift kit were cheap, labor's a diff story), and now it's not shifting @ WOT. At one point, this made me assume that there was another problem with the transmission, so I drove it lightly. Driving it with "light throttle" gives a different feel. The trans will shift through the gears pretty descent, but it's not perfect. With this happening, I started wondering if my trans settings need revamping (line pressures, shift pressures, shift speeds, etc). I drove around for a short while trying to get a couple WOT runs, as well as light throttle runs.

I'm wondering if one (or more) of "the pros" can take a look at my tune & logs, and provide suggestions (for better direction) on what I need to pay more attention to. I'm trying to learn all I can, but don't have too much time to play... work & family with young babies. Any help would be appreciated. Thanks!

-Ron

P.S. I used to get the P0740 - TCC Solenoid Circuit code prior to these tune mods. I don't get 'em anymore. I've driven the truck "lightly" more than I have when logging. I've checked the DTCs, and have found no pending codes. I hope the converter is fine, but who knows. Thanks for reading!

[1badc10]

BTW... I haven't done much engine tuning (no more than idle & off-idle quality) since the cam swap. With trans issues, the truck doesn't get put through the gears for WOT tuning. But I'll take suggestions there too.

224/224 .568/.568 114lsa w/918 springs & 7.400 p-rods
home-made intake (need a fab a "true" CAI)
ported TB (not the small TB... dunno actual size)
stock heads <--wish i could say more, but i dunno what's been done
UDP
stock exhaust manifolds <--need to be CUSTOM fab'd for LT's
true dual exhaust with h-pipe (no cats, two magnaflow 18" mufflers dumped b4 axle)

that's all i can remember, for now.

[stone]

White size tires you runnin'?

[stone]

I noticed your Shift Pressure Modifier Upshift tables are all lower than stock, try setting those back to stock..

Set up your full throttle tables like this:

[stone]

BTW you can find original copies of the stock tune for most vehicles in the Tune Repository..for the Upshift tables...

Try those settings and let me know..

[1badc10]

Running 28" tall tires (roughly 27.xx from center to ground).

I have a copy of my Yukon's stock tables. They are similar (if not identical) to any 5.3/4L60E combos in the repository.

I'll try to make a run here shortly, and post something before I head out of town (goin' back to hometown for Mardi Gras)!

[stone]

Try this for your part throttle shifts...

[stone]

I would also set the Performance, Cruise & Hot tables to the same...

[Russ K]

1badc10,

Try this trans tune. You have way to much spark timing in the main spark tables, then you have less than stock timing in your idle base tables. Your spark over & under speed tables are messed up. The even kpa rows of the primary & secondary VE tables have to match (your's don't).

The TransGo SK-4L60E kit is really just a correction kit, not a shift kit like the 4L60E-HD2 reprogramming kit.

Russ Kemp

[stone]

Yes I hadnt noticed that...that is a heap of timing!

[gman4dx266]

Dude, that is a sh*tload of spark advance!

Has someone tuned this before you 1Badc10?

[1badc10]

I've had some help with the tune based on the heads... I haven't had much time to play with it b/c it's been down for so long. I will say that it seems HELLA responsive on the low end. Traction is a BIG issue. I'll have to go back and read the tuning how-to stickies.

Stone... i tried ALL stock trans settings, and yours... same results. I'll swap the PCS and see what happens. My trans builder said to try that. I'm not too confident in this trans, and I don't wish to put any more money into it.

Russ... i'll give that a shot when i get back home tonight.

[stone]

If it isnt shiting at WOT are SURE about the tire size?

[1badc10]

If it isnt shiting at WOT are SURE about the tire size?

Went outside to confirm that when I first bought HPT before last summer. I haven't changed tire sizes. They are still 275/60R15s. Measured it using two different tape measures. I'm sure it's 28" tall. Thanks for asking.

I just got home, and am beat from driving all day. I will try Russ' changes on tomorrow, after work. I'll post results afterwards. I'll try to log as much as I can... laptop's not the greatest, and the battery barely holds a charge longer than an hour. Gonna put on charger tonight.

Thanks, guys! *edit* need to buy a power inverter to plug in truck. then i'll always have juice.

[1badc10]

Here's an update... the settings that Russ posted worked great (during the first 20 minutes of about 4 WOT runs from a dig & a few WOT runs from a 20mph roll)... it worked so great that I decided to drive to a local Subway, and lay into it to put it to the test on an open, straight road. The trans hesitated to down-shift from 2nd, then shifted into 2nd. As the PCM commanded third, the engine free-revved. I'm sitting in the truck coasting in disbelief and disappointment.

At this point, I'm ready to pull the trans and give Vince (FLT) a call to buy a built 4L65E. Only problem is, my priorities prohibit spending $1800 on a level 4 trans right now. I'm now back to square one... a trans that only has 1st and 2nd gear. This crap sucks! Thanks for the help guys!