6Speed_94Z28

Ok heres the situation guys, help me out. I sold this car to a friend of mind after a realiable transmission guy rebuilt it, it now as about 450 miles on fresh rebuild with new converter also. I drove the car about 150 miles with no prob. Hes has it for 2 weeks or so and I have had A4s that do this like u get on it in overdrive and it dont wanna shift at redline and u just back out of the peddle a minute and it shifts fine. But if u keep it floored it wont. Well this one does it in Overdrive going from 3rd to 4th if u get on it. Now is that normal or is it just the computer not used to the trans yet? Could the PCM be bad not giving it the right line pressure at the right time? Its a electronic shift trans as Im sure you all I know, and like I said I have had some do this. Put if ur not on the throttle all the way like 3/4s the way it shifts fine and firm but if its floored it won't shift till u let out of it. What could be the problem, or what is the problem? LET ME KNOW, HELP ME OUT. Im a T-56 man myself, not a A4 guy.

VK

First off, talk to the guy who built it, sometimes they know alot of tricks.

If that don't help, first replace the TPS sensor, 10$ part.

Then find out if you have diffent gears in the rear end, or different tire size/rim size other then stock (if so the computer needs to be reprogramed)

If that doesn't do anything.. might be a cracked forward piston in the tranny.. ask they guy who built it if he put in a plastic ACCUMULATOR.

Either way, talk to the tranny guy who built it. HE should have to fix it no matter what it is.

6Speed_94Z28

Its got a hypertech set up in it for the 3.73 gear, and the dude that had it before me put a TPS sensor in it when the trans was slipping really bad, but I never put one it. How could that fix it if u dont mind me asking?

VK

The tranny shift points and line pressures are controled by TPS% along with RPM and mph.

Also the torque converter lockup is partly controled by TPS%... take the TPS sensor out of a 4l60E and you will think your tranny is completly fried!

Now the 700R4.. TPS has no effect.

6Speed_94Z28

Well I guess I will try that and go from there. If that doesn't work what should I do next?

1SlowFormula

6Speed,

I got your PM, and I assume this is the post you were refering to. It looks like you have gotten some decent info above. and I would agree that you should talk to the guy who built the tranny because it is not acting right...

This however does sound tlike the guy who rebuilt it didn't really do a great job, and he probably just jumped in there and replaced the clutches (you'd be suprised how often that happens)... I would not confront him about the type/quality of work, just ask questions as to what was done and tell him what it is doing.

[RANT] This is why you should look into who is building your tranny, most shops don't do anything outside of a GM spec'd rebuild and using replacment parts. These parts are not designed to fix the weeknessees of the 4l60e, nor will they last very long in a tranny that is being rebuilt. These rebuilds normally consist of replacment clutches and steels that are not going to hold crap (not to mention the clearances are probably not checked), a single cage imput sprag that is known to roll over on itself (not a good thing), a replacement 2/4 band that not only won't hold crap but is normally being put right back on the drum that was worn down by the original band (if your lucky they will resurface it, but don't count on it), and plastic accumulators...
Does that sound like what you want to replace your stuff with? it's like rebuilding your motor and buying factory replacement parts, and not checking clearances or resurfacing the journals, yes there are shops that do that too it's called Jasper, do you really want that as your performance choice motor???
If you are going through the trouble of getting a tranny rebuilt take the care in it you would with your motor, because seriously what's the difference? Your not going to do crap without a motor or a tranny, right? Even if your not building it for racing or more HP, at least fix the flaws in GM's setup... [END RANT]

6Speed - that rant wasn't directed solely at you, hope there are no hard feelings, it's just something I think people should understand about rebuilding a tranny. And I get a little irritated when people say they went to a good/reliable shop, and now it doesn't work right. Yeah that shop may be good with other trannies, but guys need to realize our trannies are a little different and have issues to begin with that a standard rebuild will not resolve...

6Speed_94Z28

The guy who built its is a GM certified guy(worked on at the same dealership for 20 + years), he can build these things in his sleep, I bought all the stuff for the trans(over $500 in parts) and watch him put it together, he didnt just slap it together. I am very picky with who does my work. Put I dont believe the prob is in the Trans personally. Im gonna put a TPS on it and see what it does. Then I will go from there.

6Speed_94Z28

So anyone else got any ideas, Im gonna replace the TPS tomorrow.

VK

Is it only slipping 3 to 4th at WOT? Or sometimes other gears too?

Let me know on the tps sensor. . i'm going to try and ask a few tranny buddies, see if they have had any problems like that.

6Speed_94Z28

No its not slipping at all, just wont shift, pulls like a son of a gun when u hit go to WOT and then it pulls and pulls and hits the rev limiter, it just won't shift until you crack the throttle then it shifts fine. Im hoping its the TPS.

VK

well, change that tps sensor .. then let me know.

matLT1

Make sure yor fluid isn't low. My tranny did this when it was about 1/2 a quart low.

1SlowFormula

I just noticed the new converter mentioned in the first post, what converter is it and do you know where it stalls?

High stall converters (generally HIGHER then 3K-3200) have been known to cause this problem on ODB-I computers as well...

cleangene

my problem was when I put in 373 gears and b&m shift kit, had to reprogram computer for lower shift pionts in all gears, works great now, hope if helps

6Speed_94Z28

Put the TPS sensor on it, didnt fix it. Fluid is in the area it should be when its hot. Thats usually when I check it. Its the stock stall speed as the converter that came out of it. Nothing fancy. Talked to the guy who built it for me, we are gonna look at it Tues. Its busting loose pretty bad at 4500 rpm then it hits the rev. limiter. Its pretty bad compared to what it was about a week ago. So we will wait and see. Anymore suggestions?