Question : 4t60e swap

[rcp4207]

I replaced the transmission in my 1993 lumina car (3.1L) with a transmission from a 1999 lumina (3800), they both are 4t60e, but this one acts like it is slipping when I first accellerate. Everthing else about it seems normal. Could this just be a change in wiring that I might need to do?

[robertisaar]

that's because a 99 3800 lumina has a 4T65, not a 4T60E, the 65 has a pressure control solenoid and without it being hooked up, full line pressure will be present at all times.

[rcp4207]

Could I change some wiring to get it to work?

[robertisaar]

nope, with that trans, the PCM is supposed to control the line pressure, something the PCM you are running isn't capable of doing(it's intended to work with one that uses a vacuum modulator). there are aftermarket controllers out there that would work, but they are $$$$.

[rcp4207]

What if I kept driving it like it is, just slow accelleration from a stop, but all other gears appear to work normal?

[rcp4207]

I might be wrong about the year that donated the transmission, it might have been a 1997 lumina, because this transmission also has a vacuum modulator.

[robertisaar]

if it has a vacuum modulator, then it is a 60E.

must be another issue then...

[rcp4207]

Sorry for the confusion, yesterday was a long day at the junk yard and in the garage.

I placed a transmission from a 97 lumina (3800) into a 93 lumina (3.1L). It has a vacuum modulator. The speed sensor and 6 pin plug on the front are the same. I did have to swap out the park/neutral switch.

Everything appears to work except for:

slow accelleration from a stop (drive and overdrive), like it is slipping, but once second gear kicks in, everything is OK.

when on a hill (in drive or overdrive), car will roll backward when at a stop.

[rcp4207]

I viewed the transaxle connector wiring print ( http://60degreev6.com/Articles/Trans...60e_wiring.gif ).

Does anyone know if this applies to a 1997 lumina's 4T60E transmission?

[robertisaar]

no 97 lumina came with a 3800(from the factory).... it was 3100 or 3.4(but production numbers on 97 3.4 lumis is EXTREMELY low), and even then, the 97 3.4 cars also came with a 4T65.

98-99 luminas had the 3800 option, but again 4T65.

[rcp4207]

OK, I must have taken off a 3100, I was really having a bad day yesterday. Sorry for any more confusion.

[Schmieder]

I know it seems silly but, are you checking your trans fluid while the engine is running after a drive? Thats the true way to check fluid level. You may be low on fluid, that can cause it to slip.

Try removing the vac line to the vac modulator. But I warn you, it will shift hard so be easy. If that is the problem.

If it has a red strip, turn the screw inside the modulator to the right for more line pressure. You may have an adjustable turned far too low.

[rcp4207]

I dumped 2 and a half gallons of fluid in, trust me it is full. I will check the vacuum modulator out tomorrow. I had this same problem with a transmission about a month ago. It also was the later style 4t60e, i changed it as well thinking I had a bad transmission. But I am looking at wire prints ( Haynes Manual) and this later style 4t60e is a little different inside, compared to the earlier one.

I'm on the third transmission now, the previous three were all used and swapped out at no cost to me, but my labor. It's been pretty frustrating. My labor will pay off soon, I hope.

Has anyone else ever put a 4t60E from a 97 into a 93 lumina?

[rcp4207]

I was looking at the wire prints and it looks like:

The earlier style (1993) 4t60e has a 1st gear pressure switch, 4th gear pressure switch, shift solenoid A, shift solenoid B, and a TCC solenoid.

The later style (1997) 4t60e has a 1-2 solenoid, a 2-3 solenoid, a TCC (PWM) solenoid, a pressure control solenoid valve, and a fluid temp sensor.

And they both appear to be wired different. Can the switches from a earlier model be installed in the later model?
I also remember reading somewhere in one of the threads that the pressure control solenoid valve could be left disconnected along with the temp sensor. I'll try to find it again.

[robertisaar]

the 1st and 4th gear pressure switches are actually "shifter position" switches, and let the PCM know if you're trying to lock in 1st gear or allow 4th. the pressure control solenoid is something you'll find on a 4T65, it is the PCM driven equivalent of a vacuum modulator.

your PCM doesn't track trans fluid temp or operate the TCC with a PWM strategy, so neither of those need to be/can be hooked up.