GM 4L80E Transmission Electronic Modulator Shift Kit

[turbovanman]

Matt, 4th isn't OD, it's 4th. OD comes after.

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4th is overdrive, 3rd is 1:1, 2nd is 1.48 and 1st is 2.48. The OD you are referring too is the LU, which is seperate and nothing to do with an overdrive. OD simply means the gears are now being overdriven, if that makes sense, :thumbsup:

 

[matuva]

OK, got the B&M kit installed today.
Looks to do a nice job.
I will probably daily drive on #1 setting, #2 being may be a bit firm for me. I don't know if this kit reduces slippage too, I will see how it does in the days coming

 

[turbovanman]

OK, got the B&M kit installed today.
Looks to do a nice job.
I will probably daily drive on #1 setting, #2 being may be a bit firm for me. I don't know if this kit reduces slippage too, I will see how it does in the days coming

More pressure will help the clutch's apply quicker which will reduce slippage. Best deal is to reprogram the computer.

 

[kane]

Interesting, very interesting... have to make one for my Sub...

 

[kane]

I'm impressed! I made 44 Ohm and 10 Ohm selection and the tranny feels great. I want more rainy days (= wet roads) :driving:

93-95 is connected to C6 (red w/black stripe) and C11 (light blue w/white stripe)

 

[matuva]

Yes, seems it works fine.
That being said, does more pressure means more wear in the trannies; or do they afford that with no problem ?

 

[Matt Bachand]

Yes, seems it works fine.
That being said, does more pressure means more wear in the trannies; or do they afford that with no problem ?

Wouldn't be surprised if it means less wear on the clutches (which fail first usally) ... more work on the gears, drum? Its a system... similar to 'dumping the clutch' in a standard... clutch last longer, drivetrain components (u-joints, rear-end, mounts) take more beat. OH, and Tires too

I'm no tranny junkie though, Curious to see what others have to say.

I need a little something something extra shifting into OD if my RPM's land in 1600-1800 range. Feel a little 'not hooked up enough' feeling.. hard to explain, its not a slip, but I feel a little something going on before its fully engaged. Seems to high RPM for lag, but if it lands in 2k+ it engages strong and pulls instantly.

 

[625fireman]

I had the B&M shift improver plus (the 3 setting one) in a 5.7 Tahoe I had. I liked it alot. Really made a world of diff. Ran in to 2 mostly when I was towing I would bump it 3.

 

[Missy Good Wench]

I stand by Transgo shift kits.
These will work quite well with the Chip thats in the truck.

Just adding line pressure is not the proper way to gain reliability in these gear boxes.

A tranny thats slipping cold likely has servo seal issues (hard and leaking but soften when warm)

Pull the pan and see what sort of crap is in there. If the oil smells burnt or is very dark and the pan has crud in the bottom, the box is gonna need to come apart and be rebuilt.

best

MGW

 

[Missy Good Wench]

Matt

Actually if a tranny is working right (even when they shift a bit firm from a shift kit) the stress on the drivetrain is little more than stock. The biggest issue with the auto boxes is that the original programing is usually too soft.
The overlap time from applying a clutch and releasing a band or ?? in many cases allows for too much slippage and therin lies the issue.


In many cases the shift kits improve oil volume to the servos that apply the clutches and bands.

Many gearboxes over the years have had issues with internal leaks that allow too much fluid loss around sealing rings and such and this causes component failure.

I have built 700R4 Boxes (definately not my favorite little beasts) that would knock your teeth out when they shifted and never had any issues with other components.

The difference between a very hard shift in an auto and "Dropping the clutch" on a stick is that the drivetrain on the auto is loaded to full torque (or close) and the thing is moving.
Also the converter takes a huge amount of any forces out of the picture.

The 4L80 is very similar to the TH400 and the gear ratio changes are not as severe in change as say a 700R.

In my many years in the auto repair business I have never seen a drivetrain damaged from the use of a shift kit. (Unless the driver is abusing the thing anyway.)


MGW