ok, so here's the deal. keep in mind i have a manual in my ls1 now, but my previous v6 camaro had a 4l60e in it, and i had a big stall converter in it for the duration of it's life. so i know a bit about auto trannies, but i don't know if i know enough about them to diagnose this problem in my friend's auto ls1 correctly. but i'm gonna try, and let you help me out with the rest.

firstly, this car moves, and moves quick. it's putting out about 400 hp and just recently got installed (tranny and motor) into a firebird. when bought, the owner told my friend there were no problems and that everything was in good condition. i seem to think otherwise. when the car drives, it rides first gear, never once shifting. autotap will say it shifts at about 2500 rpms into 2nd gear, but the car actually never shifts; the rpms never fluctuate and they just keep rising. they would probably rise to redline under 10% throttle if you wanted them to.

to actually change the gear (and 2nd gear is skipped by the transmission most of the time), you have to let off of the gas completely, and give it gas again. this sometimes works on the first shot, and other times you have to let off/get on a series of times before something actually shifts the gear. now you are in third. third will rise like first, and rarely (although it has occasionally) shift into OD. first usually doesn't ever shift into 2nd (although autotap says it will). this is the normal driving conditions for the car. it's very tough to drive because of these problems.

when you get on the car, the limiter is always hit. not once can you miss the limiter. it's not just a simple bang either, it's a "i'm trying to override the limiter i'm hitting it so hard" kinda hit. it's bad. we messed with the limiter, raising it to 6400 (don't worry, aftermarket valve springs) and lowering it also. we also fucked with the hpp3 trying to make it work, but nothing cured the problem. if you were lucky, on a WOT run you could catch the car and let off of the gas before actually hitting the limiter. most of the time you weren't so lucky.

the car feels like a slipping clutch in a manual ls1 does. it just doesn't grab. you punch it and it's through the rpm band and hitting the limiter before you have time to realize it. and the whole time this is happening, the car isn't moving. there is no acceleration really. it feels about like a neutral rev, only a little bit more umph in the car - but definietely nowhere near the power the car is putting out.

i put the car in OD and tapped the brakes. at this point, the converter is supposed to unlock. it does not. the converter doesn't budge. this converter seems to be the problem, or so i think. but, i don't know enough about the internals of the transmission, so me and my friend need all the help we can get. i'm sure he'll also add on to my thesis.

 

this is my car, btw.

anyone have any thoughts?

 

been their, done that.
The second gear was so glazed that when I would got WOT from a dead stop it would start off fine in first and as soon as it would hit second it would bounce off the rev limiter. Autotap it and you will see that it is skipping all the gears.
Ended up getting a new trans.

 

that's not what i was hoping to hear.

 

Sounds like what happened to me. It would go through first fine. Second it would bounce off the limiter a few times and finally catch on and be alright. If you were in 3rd or OD and floored it it would bounce the limiter than catch on. Eventually it got so bad you had to play with it until it finally shifted into OD because I got nothin in 2nd or third really. Turned out 2nd and 3rd were fried. Lucky for me though I got a new trans under warranty at the time.

 

Also, the car has a MAF with no screen in it-

I read that without having the screen, it can decrease your tranny line pressure, and cause these sorts of problems.

I can't seem to get ahold of a screen- but, what if I use the HPP3 to increase firmness 50% or so and compensate for the line pressure decrease?

 

sam, i don't think so. sounds like your tranny is fucked - like those guys said.

 

I dont think the MAF screen would do anything anyway.

My car had the same type of trouble.... took it back to dealer and they said it was the 2-4 band. I got it fixed under warranty and it lasted a year but now its slipping again. Damn 4L60E!

 

Well search MAF screen in the automatic forums only. You'll see several posts where the guys lost line pressure and had similar problems like mine until they put the screen back in. I'm just hoping it that and not something serious (which it probably is)

 

Have you smelled and/or looked at the trans fluid?

 

Descreening you MAF will drop the line pressure. Basicly the trasmission is reading air intake to detemine whether or not to do a soft or hard shift. A soft shift at WOT is bad. Unless you have a shift kit or have rasied the line pressure do not use (ported, descreened, after market) MAFs

 

one way to test it is by starting from a dead stop, move the gear into first, begin slowing driving then manually shift to second, so on and so forth. If that works, then start at a dead stop again and try WOT runs, just make sure to shift out of first right away.
at any rate, you sound like you need a rebuild.
Speed Inc has some great new trannys. They are installing a new Evil Stage III in my TA right now

 

1st seems okay, but it doesn't want to shift into 2nd.

2nd gear feels like ******* neutral.

3rd gears feels OKAY...

OD is okay.

The guy I bought the tranny from said it had 19,000 miles and shifted perfectly. I drained all the old fluid, put new proper fluid in, leveled it off correctly, and went. But it never liked to WOT shift- ever.

And then after about 150 miles it started slipping real bad.

 

2nd gear band is shot, happened to me three times. Hence the reason to go with Speed's Stage III setup. It sucks man, I feel your pain - I really do.
But you are going to need a rebuild.
Do you have autotap? If you do, you will see that your trans temps are through the roof. mine were hitting 225+ and that was with a trans cooler.

 

That'd be nice just not in the budget.

 

Look at a Crate 4L65E (L65) Tranny...I do not think GM is charging much at all for them and they are great trannies.....it is a DIRECT BOLT UP.....everything bolts up just like it did to ur 4L60 and the computer can control it w/no problem.

 

Thanks Josey! Found with Google:
GM 4L65-E / 4L65E / L65
The 4L65-E differs from the 4L60-E in these ways:

* Five-pinion gears for input and reaction gear sets (versus four-pinion gears in the L60)
* Heat-treated stator shaft splines
* Induction hardened turbine shaft
* Heavier-duty low/reverse roller clutch
* Additional friction plate added to 3-4 clutch (seven plates versus six in L60)
* Shot-peened output shaft
* Revised valve body calibration.

Despite these upgrades, the L65's gearing remains the same as the L60's: 3.059 for first gear, 1.625 for second, 1.000 for third and .0696 for the overdrive.

We fell that the 4L65-E offers the best compromise to a five-speed manual. It's got great strength and the gear ratios complement a car's power-to-weight ratio.

 

NP...good luck bud...

 

Same size driveshaft? Torque Converter?

 

yes.....direct bolt in.