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GM 4L80E Transmission Electronic Modulator Shift Kit

There is a write up somewhere on how to build your own for line pressure. The TCC shudder part I dont know about, do you need that. My local trans parts place sells foolers like that, but I dont know if there available where you are.

I built one out of radio shack parts and an Ernie Ball guitar knob. Cost more for the knob than the parts, around $20 total IIRC. Its just four resistors and a six position switch, that ties across the pressure control solenoid wires to the trans.

1 50 ohm 10W 5% Wirewound Resistor (2-Pack)
Catalog #271-133 $1.99

1 10 Ohm 10W 5% Wirewound Resistor (2-Pack)
Catalog #271-132 $1.99

1 Project Enclosure (3x2x1")
Catalog #270-1801 $2.29

1 2-Pole, 6-Position Rotary Switch
Catalog #275-1386 $2.99

1 Grid-Style PC Board with 750 Holes
Catalog #276-158 $3.49

Sorry I dont have the plans anymore, that computer died on me, and I cant remember which site I found it on, think it was the place.

I run mine on the second notch(50ohm's IIRC), first notch is stock(open, no resistance), but I have the Transgo-HD kit with stock TCM programming, it shifts about right there.
 
thanks guys.
Actually we're trying to solve a problem on a 1997 K1500. The owner is complaining about excessive slippage during shift, especially at 1-2 and when cold.
I drove myself this truck (hot) and didn't notice excessive slippage though.

We swap a "used but good one" trans, and the owner says he still feel excessive slippage...

I think we will then change all solenoids in the trans, and I'm searching for a device wich can reduce slippage.

Tim, could you let me know more about this "mechanical shift improver body" ?

Thanks.
 
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I think he's talking about a trans/valve body shift improver kit, like my Transgo-HD.

Tie a 25ohm/10watt resistor across the force control solenoid wires, see how it shifts, should bump line pressure up 10-15psi.

Is this in a gas truck?
 
Hmmmm,

If you have scanner available, see what shift times are. Are these soft shifts @ part throttle or full? Did he swap converters also? Do you have another PCM to try?
 
I use the B&M version and it firms up shifts nicely. It has 3 settings: stock, firm and almost too firm. I run it in the middle. On the high setting it will break the tires loose in the rain on moderate acceleration during shifts. As for running it with a reflash, If Eddzed(spelling?) doesn't chime in PM him. I think he ran a B&M like mine with his GL4 at one time, don't know if he still does.
 
I had the same issues with shifting sloppy between 1-2, it ended up being a poor connection at the PCM plugs, this happening after I installed a high idle switch. I wiggled and tightened the plugs and voila, it was back to normal. No problmes since, that was in dec. of 2008. Just one more quick and free suggestion to try.
 
Monarkman said:
I use the B&M version and it firms up shifts nicely. It has 3 settings: stock, firm and almost too firm. I run it in the middle. On the high setting it will break the tires loose in the rain on moderate acceleration during shifts. As for running it with a reflash, If Eddzed(spelling?) doesn't chime in PM him. I think he ran a B&M like mine with his GL4 at one time, don't know if he still does.
Click to expand...

i'm still running the b&m shift plus. nice hard firm shifts. I run it at the firmest setting. Ed
 
You actually only get two settings. In the neutral switch position, it is off (stock). You can switch to the left or right depending on if you want firm or extra firm. Jet also makes one. It is much more expensive but has 3 settings above stock.
 
Here ya go, for about $20, stock plus five positions.

Switch position,
1=open
2=45ohm's
3=35ohm's
4=25ohm's
5=20ohm's
6=10ohm's
 

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OK, just ordered one.

I was smoked by my buddy who's running my previous V2.0 Heath PCM + a TM.

Obviously, his truck shifts really more firm and so kicks in better and pushes stronger.

He tried mine, and says this is weird, mine is acting as if I was towing a load or if my rear brakes didn't fully disengaged.
We check brakes, nada.
Not even being able to chirp tires, obviously slippery tranny.
 
I could use a little firmness shifting into OD for sure.

Also what bothers me, is if I manually shift into 3 from OD the TCC Unlocks, shifts, then locks up again. Unnecessary wear. I really hate no control of the TCC. I suppose a Heath Reflash would address alot of this issue?

Doesn't the HEath PCM control shift pressure too? I know it controls TCC.
 
Matt, 4th isn't OD, it's 4th. OD comes after.

Matuva, I run the B&M too, been pretty happy with it. When I reworked my valve body I modified it to shift firmer, so now it's really too hard in the firmest setting. But I love the nice firm 1-2 shift, it really kicks you in the pants. I was a little unsure what you were saying at first, slippage is a bad thing, but soft shifts aren't that serious. They will make more heat, but actual slippage in gear is bad, and not something you can fix electronically. If you have slippage it's because something is going.
 
You're right. I'm not very trained in tranny diagnostic, and what I may consider as slippage might be just soft shifts. My V2.0 Heath reflash is Towing dedicated, as my GL4 is "performance" enclined.
I remember that I was complaining with Bill about hard shift between 1 and 2 with my V2.0 when he was on the way to burn my GL4, so he may have consider my guess and make shifts smoother.
That may explain. I should talk to Bill I guess.
The fact is that the V2.0 really kicks you in the pants, as the GL4 is more "soft", though it pushes strong too.

I will see if the B&M helps, I will change oil in tranny and put in some synthetic.
 
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