95 Lumina with 3100 and 4T60-E. I was accelerating kind of hard and heard a bang type of sound and the car started slowing down like I was stepping on the brake. I was only up to about 35mph when this happened. So now under normal acceleration the trans wont shift in 3rd. If I manually shift or keep it in 2nd it will drive fine for the 1st and 2nd gear range but as soon as I shift into 3rd its like stepping on the brake. Also I do have o/d.

I've searched over and over and cant find anything. Help would be appreciated.

Anytime you have to use the words "bang" and "transmission" in the same description, it's pretty safe to assume you need to start pricing a new one....

I'm willing to fix it myself, just trying to find a general area before I take it apart.
I have never done anymore to a trans than tune ups, swaps and half-shaft replacements but I know motors and I can fix anything else mechanical...car or not.

I know something bad broke but im bored dammit! lol

I'm willing to fix it myself, just trying to find a general area before I take it apart.
I have never done anymore to a trans than tune ups, swaps and half-shaft replacements but I know motors and I can fix anything else mechanical...car or not.

I know something bad broke but im bored dammit! lol

I don't know....in general, I think the clutchpacks usually work on more than one gear per set, so I'd think there'd be two gear ranges failing you if that were the case...

When you say it slows, is it like it's actually dragging, or just slipping? Like does the motor overrun the gear speed, or it just labors and bogs down?

No matter what it is coming out and apart so you will see the failure, get a good trans o/h book these units are not easy!

Motor over runs the gear speed

I know it cant be easy but if a human can do it and it doesn't require quantum physics I can do it.:grinyes:

So go to it, again, get a good guide! Keep us informed how it goes.

kindof sounds to me like a stuck valve or the sprag flipped. how many miles and exactally how hard were you accelerating?

Well over 100,000 not sure. Turned miles back a few years ago. I rebuilt the motor and had a shop rebuild trans and send out torque converter. So maybe around 120,000.

I hit the gas hard but I never floor it...well i did once racing a Caddy, that was some funny shit. I new i'd loose but who cares, it was fun. I drive pretty hard but hardly drive my Lumina. I got a trans temp gauge so I make sure the temp is up before I do anything retarded.

I did a trans tune up over the winter too. Didn't notice anything wrong.