Trans Slipping

I have a 1995 Chevrolet Lumina with the 4T60-E transmission and it is slipping in first gear. but only from a dead stop and when you really give it the gas it wont shif out of first until you let off the gas. I have replaced the filter and put in new fluid and some Lucas Brand "Stop Slip" I put it in 2 days ago how long does it take to take effect. Is it time for a new tranny? This car has 138,000 miles on it. I hope someone can help.

I haven't heard good things about stop slip. But it probably is time for a new transmission. The 4T60e does not have a good reputation for being a reliable transmission if abused.

I have been reading about the Trans Vaccum Modulator and this seems to control the selinoids for shifting. So I unplugged it and took it for a ride then it seemed to short shift and it didnt slip anymore but only when it is cold. When it gets warm then it does the same slipping again. I think this Trans Vaccum Modulator is bad. What do you guys think?

I have been reading about the Trans Vaccum Modulator and this seems to control the selinoids for shifting. So I unplugged it and took it for a ride then it seemed to short shift and it didnt slip anymore but only when it is cold. When it gets warm then it does the same slipping again. I think this Trans Vaccum Modulator is bad. What do you guys think?


OK I replaced the trans vaccume modulator and that was not the problem so I replaced the Vehicle speed sensor and that was not the problem. Then I got to talking about it to one of my friends and he said to check the wireing and that was it the wire had corroded in half just behind the connector for the VSS.

Urgh the 4t60e transmission is one of the worst trannys i think gm ever made thats why i see 80 year olds drive luminas. I had the same problem at 99,000 miles you have alot more miles then me and im surprised that tranny is still holding up. I have also heard that when u try to floor it it will not shift to second it will sound like its reving thats the problem i had be4 my tranny went. Just ease off the gas when that happens. I have taken my Lumina to the tranny guy about 3 times already my best advice is to get it check out now dont wanna end up like me i blew the tranny on the highway coming home. She wouldnt shift to 3rd lol i was stuck doing 45. In my opinion that transmission sucks. :banghead:

check the vacuum lines to the vacuum modulator and or any other vacuum leaks that will make a trans do some screwed up things if it is lossing vacuum also try (greased lightning trans additive) it helps

Ya'll actually trust that transmission additive crap? I wouldn't put that stuff in my transmission to save my life. It's got FINE shavings of stuff to cause the transmission to quit slipping, but over a period of time, it will ruin the transmission. The same way for that no-smoke engine oil additive that causes your engine to quit smoking. That stuff gets all over the crank, rods, and everything else down in there. It's a pain to get out, and it'll clog the filters in a heart beat.

While I don't have any experience correcting automobile problems, I did have the same one you are referring to, I think.

1999 Lumina LTZ (3.8L) Auto seemed to have wheel slip with semi-hard start from dead stop. Kind of like the drive wheels were in gravel even though on dry pavement. I could do a full power takeoff (after warm-up) with no problem; just smoke the tires but no hop. Shop said that the problem was no problem at all, just the limited-slip differential doing its job. Maybe?? Got into the habit of making low gee departures.

One day later in the week the electrical system starts shutting down after about 20 min driving time. First thing I notice is the tape deck starts dragging and the radio will barely play. Alternator light is on. Wheel hop was evident even on normal start off. Am close to the shop so I drop in and found that the alternator has croaked. They replaced it with a new Delco.

I can't explain it but since the alternator was replaced (4 months ago) I've not had the first sign of wheel hop in any circumstance. Could the wheel hop and a dead alternator be connected? Beats me.

If anyone can connect the dots for me I would be grateful.

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While I don't have any experience correcting automobile problems, I did have the same one you are referring to, I think.

1999 Lumina LTZ (3.8L) Auto seemed to have wheel slip with semi-hard start from dead stop. Kind of like the drive wheels were in gravel even though on dry pavement. I could do a full power takeoff (after warm-up) with no problem; just smoke the tires but no hop. Shop said that the problem was no problem at all, just the limited-slip differential doing its job. Maybe?? Got into the habit of making low gee departures.

One day later in the week the electrical system starts shutting down after about 20 min driving time. First thing I notice is the tape deck starts dragging and the radio will barely play. Alternator light is on. Wheel hop was evident even on normal start off. Am close to the shop so I drop in and found that the alternator has croaked. They replaced it with a new Delco.

I can't explain it but since the alternator was replaced (4 months ago) I've not had the first sign of wheel hop in any circumstance. Could the wheel hop and a dead alternator be connected? Beats me.

If anyone can connect the dots for me I would be grateful.

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The computer in your Lumina operates on 10 volts minimum. There is no published voltage specs but I recall being told this at one of the GM product seminars I attended. It could be 11 volts- who knows for sure.
If your alternator was bad and the battery was partially discharged at the same time, its possible that the computer or ECM was not getting ample voltage and and current flow to make things operate normally.
The wheel hop and tranny slippage is fairly normal if you are in a hurry to go from reverse to drive. The system needs a second or so between shifts to get itself set. You may need to pull the trouble codes- if any from your transmission- you could have skunky fluid and sticky solenoids.
I have a 99 LTZ with 98,000 miles and have had no problems at all.
My fluid was flushed at 35,000 and is due again now. It made a big difference on the first flush.
Bob

Sorta new here so ......Hoosier1 or Bob,
Seems as though you might be dead on about voltages causing puter not to work to specs. Mechanic friend speculated that the voltage/amps dropped after a 30 min. drive due a faulty alternator and low battery. He says that the power required by some systems (radio, tape deck, abs, horn and lights) cause them to trip off-line before the puter and finally even it goes south but, prior to total shutdown the onboard puter is suffering from too little juice and it just gets flaky. Since the trannie is controlled by it (puter), it flakes also. Gravel pit!!

Had wondered and even checked the codes to no avail. Seems that the puter that providing the codes is so low on juice it didn't note the irregularties. While I didn't get any codes I haven't had the problem since I replaced the alternator.

I thank both you and my mechanic friend for "connecting the dots".

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Hi there, I'm having a transmission slipping problem with my lumina too. It normally happens when I'm trying to speed up from a slow pace or from a complete stop. The engine will rev but the car won't speed up. If I let go of the gas for a couple of seconds, I feel the car kick into gear and it's normally fine from there BUT lately, it's been taking a little longer to kick into gear. This has been happening for months now and ever shop I go to tells me its fine when they test drive it (obviously it never happens when they're driving!). It only started happening after I had a transmission flush done in the fall. I'm not a car person so I'm hoping someone might be able to tell me whether its time for a new transmission or not? It's an old car and I don't know if it's worth it!