Difference between 4L60es?

[darkz711]

Is there a difference between the 4L60e in the z28s and the trans ams/formulas? Or is the only difference in ECu between them? I know the 4L60e can be started in 1st in a trans am but in my z28 it was only able to be started in 2nd. is that just a programming thing?

[TraceZ]

The transmissions are the same.

The reason you couldnt manually select 1st was because GM had to do that to meet rolling noise standards with that particular gear ratio in the rear end.

GM blocked it out by restricting the actual shifter from going back another notch. It is a common and simple mod on those cars to cut out the tab blocking the shifter so it can go back into 1st.

[Joe K. 99 Zeee!!]

Maybe I don't understand, but all cars start in 1st gear. When you select 2nd, it just locks out higher gears.

As far as I know, the transmission is identical within the same model year. There were some differences in ECU's in that certain T/A's had a performance shift button that would firm up the shifts. Is your Trans Am a 93?

There were different gear ratios in the '93 F-bodies. The 93's also had a 4L60 vice the 4L60E. The main difference being the variability of the shift firmness in the E version. Now the reason you can't select 1st gear is due to noise restrictions. At certain speeds in 1st gear the car exceeded EPA restrictions.

You can modify it to select 1st gear very easily. Take off the plate over the shifter and try to downshift it to 1st. You'll notice that the stick will come into contact with a plastic nub. You shave that off and you can select 1st.

[darkz711]

thanks guys, ya I was just looking at the auto sitting in the garage and someone told me that there was a difference between them and I didn't think there was so you guys just confirmed what i thought. The auto isn't in my car anymore, so i wont be doing any first gear mods

[Performin Norman]

As Trace said, the trannys are the same. Not having the 1st gear selector only means you can't hold it MANUALLY in first gear. The shifters are even the same. The only difference is the block that Trace meantioned. It'll take you about 10 minutes to removed the shifter selector plate and knock out the block. I used a chisel and hammer. Voila.

[Kevin - Blown 95 TA]

I used a chisel and hammer. Voila.

Do you condider yourself an artist or a surgeon?

[roastm]

i may not understand what you guys are talking about i run a f-body club in maine and we have about 10 cars , diff. years, and models and i have never seen one where you cant select 1st gear in my 94 Z you canselect from all 4 gears. what years and models can you NOT

[roastm]

this is the pic

[TraceZ]

i may not understand what you guys are talking about i run a f-body club in maine and we have about 10 cars , diff. years, and models and i have never seen one where you cant select 1st gear in my 94 Z you canselect from all 4 gears. what years and models can you NOT

The 4th gen with 2.73 rear cars have no 1st gear selection [or #1 on the shift indicator] due to meeting a gov mandated noise requirement [ that could only be met by a 2nd gear roll by..]


http://web.camaross.com/forums/showt...ear+select+mod

[Jeff95TA]

There were some differences in ECU's in that certain T/A's had a performance shift button that would firm up the shifts.

I believe that button just delays the shifts a little longer under partial throttle. I don't think it changes the firmness.

[Joe K. 99 Zeee!!]

I always thought that it might be similar to the B&M electronic electronic shift improver. It used a resistor chip to change line pressure. If I recall, the B&M thing didn't improve acceleration, it just had the car shift firmer. Maybe the Firebird button does more than that....I'm not really sure.


Here's some more info from the F-body FAQ:

Q: What's the difference between the 4L60 and 4L60E transmission?

A: The 1993 cars came with the 4L60 automatic transmission while the 1994's and later got the electronic version (4L60'E'). The 4L60E got an electronic valve body which can vary the shifts and feel dynamically to meet the existing driving conditions. Actually, if you drive a '93 and '94 (under normal conditions), there is a noticeable difference in that the 93 shifts are much more firm and abrupt. The 94 (and later) have a "variable" feel depending on throttle position, which of course at wide open throttle, feels like the 93. This electronic valving is also supposed to reduce the wear over the life of the transmission. If you have a 93, you might want to try driving in 3rd (or "D" on the Pontiacs). Once the revs get to high in 3rd, put it into 4th (or "OD") manually. Due to the valving, the shifts should be much firmer at all times in 3rd than 4th.

[Kevin - Blown 95 TA]

I believe that button just delays the shifts a little longer under partial throttle. I don't think it changes the firmness.

It changes the firmness too. There's a separate table for the performance shift pressure offsets.

[Jeff95TA]

It changes the firmness too. There's a separate table for the performance shift pressure offsets.

Thanks for clearing that up!

[Sin_Cere]

More Information: Scholars Only

It changes the firmness too. There's a separate table for the performance shift pressure offsets.

Could someone please elaborate on the technical impact of this "Button?" I have the performance transmission option on my auto and I certainly feel the difference when it's depressed. The car seems as if it goes higher into the RPM's before shifting. I heard someone use the term "stiffer," and I would also agree with that.

I would really like to know what the specifics are on this option... any scholars?