Just installed a new 4l60e still slips..pcm problem?

[chevnut55]

I just replaced my trans in my 69 after the last tuner toasted it for me. so $2k + later I got a new one in and it still slips under throttle. and now has a bad starter whine for some reason.
Is this a pcm problem, I ran out of tuners around here and about to give up.

[Red67Mustang]

I rebuilt the 4L60E in my old 4x4 several years ago... If you're putting enough power into it to push through the clutches, you may end up breaking the stock sunshell... Hopefully the one you just installed has the beefed up 'beast' sunshell in it.

Assuming your computer is properly controlling the Trans to start with, you may wish to consider increasing line pressure.

http://m.summitracing.com/parts/trg-4l60e-boost

http://www.thirdgen.org/techboard/transmissions-drivetrain/426063-4l60e-transgo-vacuum-modulator.html

[MarkB]

The first thing you need to do is get hooked up to a scanner and see what the pressure control solenoid is commanding. I would do this with a pressure gauge hooked to the transmission so you can see what is actually going on. It could be a tune related issue. But this is the only way you are going to see what is really going on. Did you put a different transmission in or rebuild the one that failed? Let me know a few more details and I will see if I can help you out.

Mark

[chevnut55]

I just put in a mad dog stage 2 trans with the level 2 shift. its all rebuilt/new/tested.
Thanks mark,The last trans was used with c5 vette parts and a shift kit, it was strong and the 1st tuner set the line psi and **** points but I had to bring it to another tuner because the 1st could not get it running correct and it seemed fine until ,I picked it up at the second tuner , he said the psi and shift points were screwy and did not know what the 1st guy did but when I went to drive it home there was no drive or o/d.
The 2nd tuner toasted the trans so I do not want to go back to him and the 1st is mad I had to bring it somewhere else.
I need to get it straightened out because my house/shop is on the market and the wife says Im done spending money on it.

[Steve Chryssos]

Sometimes when people say their trans is slipping, they don't realize that it's really in limp mode meaning 2nd gear only. The car feels sloppy off the line because it's in second then once second is topped there is a dragging feeling on the gas with a false neutral feeling off the gas. So right off the bat:
-- Is your car shifting at all? If not, it's likely to be in 2nd gear only limp mode -- not slipping.

[chevnut55]

Been working on it all day.
It shifts in every gear, soft and slow. it takes awhile to go into any gear..feels like the original powerglide.
manual shifting it hops like a low rider like it did before I had it tuned.
I have a cheap billet/braded dipstick that is pissing out fluid at the base all over the exhaust so I took out a qt thinking its overfilled but feels like its slipping worse.
Im at a loss now. I guess take out more fluid and call the tuner again.
Anyone else have their stock LS swap tuned 6 times????? $500.00 a plug in this sucks, 1 more problem and Im droping in a big block 5 speed.

[djfxall]

Mad Dog Transmissions, there is the problem my stage 2 mad dog is in pieces right now he didnt even put a beast sun shell in mine I put allot of thought to this and have vowed to speak up against companies ripping people off with false claims and false advertising also. Bet he even has some ocean front land in Colorado for sale to. If I had to do it again I would do one of 2 things bought from Mark and got a reliable trans with everything I paid for in it or bought a good core and built my own which is where I am at now where a 2/4 band replacement is turning to an expensive rebuild as I am replacing parts I thought I already owned.

[MarkB]

Where are you located? Maybe I can recommend someone to take a look at the program for you. I would try and avoid driving it, if the pressure is low you can damage the transmission in a few miles. The transmission being overfilled wouldn't cause it to act this way. Low on fluid would. Since you have a braided fill tube, I would recommend starting the vehicle and pulling the actual tube out of the transmission to check the level. I have seen many of these tubes that are not correct. When the vehicle is running the fluid level should be just above the pan gasket area, stick your finger down into the transmission through the tube opening and see where the level actually is. Just a recommendation.
I would still like to see what the computer is commanding compared to the pressure. Feel free to send us a e-mail directly to [email protected], we will help where we can.

Thanks,

Mark

[chevnut55]

Im in s.e. ma./ RI.
After looking into it or under it while running I found the cooler lines leaking badly, not the dipstick hole.
they did not leak before and I used Teflon tape and they are tight. I can not get it to stop leaking for some reason.
so the fluid is low, I added more fluid to test it and its better but still weak.
Can the cooler line leak be cutting the psi that much?

[MarkB]

I do not have anyone in your area that I am familar with but I have put out a couple feelers for someone who could calibrate the transmission. The cooler lines would not limit or hurt the psi, so that is not causing anything more than a leak. I would not recommend any teflon tape on the fittings, they are a inverted flare fitting and they have to fully seat against the flare to seal. Teflon tape can normally cause more harm than good. Be sure the fittings are clean and that your flare is good without any damage and tighten without any sealant.

[csouth]

Chevnut55,

Are you sure there is nothing wrong with the trans? I have no experience with MD, but it seems others have had negative results on new units.