Manual Auto

[ACAT]

Hello All! I have a custom street rod w/4t60e that I want to shift manualy w/o computer. From what I have read on this forum I can use p/n switch for 1&4 and 2&3 will operate if solenoids are unpowered. What about reverse? Can lockup be done w/switch? In any gear? Where is I.D.#? THANKS!

[sharkey]

you would need to power the shift solonoids in the right sequence to get the correct gear. im unable to find the actual chart, but this is an example

solonoid A B
1st on off
2nd off off
3rd off on
4th on on

you can wire it up so you have a switch for each gear, or just 2 switches and remember the combo of on/off for each gear. lockup could also be on a switch. reverse is done with the manual valve, no solonoids need to be on for reverse.

the biggest issue with doing it this way is you will always be at max line pressure, as you have nothing to controll the epc (electronic pressure controll) solonoid. this will mean rock hard shifts at chirping the tires at light throttle.

running switches is fine for a race car, but anything driving on the street needs line pressure controll. for this reason, you will want to run one of the tci (or other) 4l60e controllers. they do work well and are worth the money

[CNCguy]

Depends on the year/model of the transmission. I don't know when they switched to EPC but a '95 4T60E uses a vacuum modulator. It also has PWM (pulse width modulated) TCC (torque converter control) that can be left unhooked to create firmer TC lockup. The OBD-I 3.4 DOHC 4T60E's didn't use EPC.

Just a guess, but it seems like the EPC wasn't used until OBD-II came out.

[sharkey]

oops, my bad, i read street rod and though i saw 4L60e.

yea line pressure is controlled by the modulator, so you can use switches to controll the solonoids.

[ACAT]

Thanks for info. So the modulator controls line pressure? Will this avoid " rock hard shifts " ? I may just use 2nd&3rd since they can be shifted w/o 12v. A 2 speed. Yes! Car only weighs 1500lbs. Where is ID# for gear ratios? .

[sharkey]

a 4t60e is in failsafe with no power applied to the solonoids, meaning 2nd gear only, it wont shift. you would need to apply power to one (or both) solonoids for 3rd gear. at this point, why not just wire up both solonoids and lockup and you will have something that cruises at a decent rpm aswell.

[95Grand-Am]

a 4t60e is in failsafe with no power applied to the solonoids, meaning 2nd gear only, it wont shift. you would need to apply power to one (or both) solonoids for 3rd gear. at this point, why not just wire up both solonoids and lockup and you will have something that cruises at a decent rpm aswell.

So, if I only want 2nd gear and reverse I can just unplug the trans? I don"t care about lock up or any thing else. This is for my race car. This will problably set a fault code do you think it will hurt engine performance?

[sharkey]

yes it will set codes and will put the pcm into failsafe, pulling timing.

[ACAT]

If you look under "transmissions" on this website it states that in failsafe mode shifting to overdrive will net 3rd gear. Shifting to 3rd will too. ? Shifting to 2nd will net 2nd. I think solenoids produce 1st & 4th. I just want to get this project on the street for now to see if other issues pan out.

[sharkey]

shifting to 2nd may give you manual second, meaning you will have engine braking. manual 3rd will give you failsafe, so with od.