4L60E shift override? I’m confused…’94 Z71

Hello,
I caved to peer pressure this week after work and did a burnout in my 1994 Z71. My truck is: 5.7 TBI, auto trans, 4x4, extra cab, step side. Powertrain is original, 221K miles. I pulled the shift lever down into 1st gear, but when it hit 4K rpm it shifted on its own. This surprised me.
QUESTION: Does my truck have some sort of override that will shift despite the position of the gear selector?
NOTICE: I don’t care what you think about burnouts. Your opinions about the stupidity of burnouts, waste of rubber, etc are irrelevant to this thread and not welcome.

The truck runs/drives/shifts perfectly…before and after the burnout.

Southwest ORV said:

Hello,
I caved to peer pressure this week after work and did a burnout in my 1994 Z71. My truck is: 5.7 TBI, auto trans, 4x4, extra cab, step side. Powertrain is original, 221K miles. I pulled the shift lever down into 1st gear, but when it hit 4K rpm it shifted on its own. This surprised me.
QUESTION: Does my truck have some sort of override that will shift despite the position of the gear selector?
NOTICE: I don’t care what you think about burnouts. Your opinions about the stupidity of burnouts, waste of rubber, etc are irrelevant to this thread and not welcome.

Click to expand...

No opinion on your burnouts!

Yes, these units will shift on their own even on Manual 1 (maybe also on 2?)

There's something done to the valvebody to modify that, but I don't know the specifics. Watch YT channel Precision Transmission and he's mentioned this in several of his videos.

stutaeng said:

No opinion on your burnouts!

Yes, these units will shift on their own even on Manual 1 (maybe also on 2?)

There's something done to the valvebody to modify that, but I don't know the specifics. Watch YT channel Precision Transmission and he's mentioned this in several of his videos.

Click to expand...

Ok! Thank you. That explains it.

What the hell is wrong with burn outs? I wouldnt do it in a 4x4 but that's just me after watching my Burb try to jump off a RWD dyno after some dumb ass tech F'd up, not realizing it's a 4x4. I almost F'n hit em. the front wheel drive is always slightly connected.

But anyways a 94 is very early like the 2nd year for the electronic controlled tranny and it is programmed into it somehow. this is so you dont destroy the transmission.

get into a couple 4l60e technician manuals and you can find this out.

I'm no expert by any means but Iv read it is a built in fail safe. 1st gear is for sand or mud, I wouldnt think burnouts is a good idea in 1st.

GM transmissions have forced upshifts from manual 1 or manual 2 since forever.

That was a part of the powertrain preservation strategy since at least the '64 TH400, and probably goes back before that.

Keeps inattentive people from blowing-up the engine or the transmission when they get too carried-away with the gas pedal.

Most shift-kits eliminate that "feature".

How long was the burnout?

Caman96 said:

How long was the burnout?

Click to expand...

Longest I’ve done since high school 20 years ago! I baby this truck, but I work with a bunch of gear-heads (like me) and Monday night after the annual work party everybody got in the mood and started smoking the tires on their Chevys. It was fun. I cheered them on, but I didn’t join. Since that night they’ve been pestering me to light them up…all week. On Friday I finally caved to the pressure. But I made the conscious decision, knowing the costly risks to my truck, that if I’m going to do it I’m going to do it right. I put their burnouts to shame, and they’ll leave me alone now.

Pics they sent me after.

Easy there newbie! We're not so quick to judge!

Welcome! Frank (avatar pic) wouldn't do a burnout on teflon coated ice but pics please!

I typed this before the pic! Sorry!