4T60 is Freaking Me Out

[ns87]

Backround: I don't know its history before 107k. At 107k it was flushed. I flushed it again 111k, 114k with filter change, and 122k I changed fluid with filter myself bc I felt the upshifts getting bad again. I cleaned off the magnet (the previous shop didnt ) No giant metal chunks, only finely grain black ones.

 

The shop that did the 114k change broke my transmission filter mounting clips? If these aren't clips, there are random metal clips that hang from a line inside the pan and look like they should be holding the back end of the filter up. The filter also left rub marks all on the inside of the pan. This filter wouldn't just go up level like the one when I did my Ciera's (TH125).

 

I've checked the fluid four different times on level ground, with the car warmed up, running, and in park.

 

Time #1 I was low, added half a quart. Shifts seemed much firmer after, but almost too firm. The car also didn't coast well and would slow down dramatically even down hill before. After adding, it was better.

Time #2 I was not only way above, but the fluid was foamy. Didn't do anything.

Time #3 Next day, I bought a hand pump to remove some fluid. When I checked before pumping, the fluid level was not only dead on, but not foamy. Car felt like a parking brake was seized (but my pb is disconnected).

Time #4 The fluid level is once again WAY over and foamy. Still haven't done anything.

 

Now: My tranmission slips pretty badly only in second gear, when the transmission hasn't warmed up and only right before a 1-2 upshift, or during a 2-1 downshift (its around 20mph). The upshifts still seem way too firm, but my car drove perfectly otherwise. I also want to add that my brakes are really bad, and I'm sure the rear ones are intermitantly seizing. Would this cause my transmission to shift firmer bc its working harder in any way?

 

I heard someone mentioning how they replaced a part on the transmission to control firmness? I assume its a vacuum part bc I don't have the E transmission.

This car is my daily, and I don't have a lot of money for a transmission shop to diagnose (especially if its intermittent). Is this transmission toast? I'm seriously considering buying a rebuilt one from bluegp just for piece of mind if this thing is going to die. The most I can spend is 600 to resolve this problem.

 

Thanks for reading all this!

[Crazy K]

the poart that is replaced would be the vacuum modulator that would be on the front of the transmission, you will see it looks like a canister, and has a steel line running to it.

 

this is usually replaced if your car is having harsh 1-2 shifts... maybe the other way too...

 

try this, disconnect the hose from the modulator and the metal line and spin the modulator so it faces down, if trans fluid is bad, then you definitly have a bad modulator. otherwise I'd replace it only if you are having harsh or maybe even delayed 1-2 shifting.

 

here's my suspicion... if you of the shop had beten on the filter to get it to slip into the bore that it should bo into, you may have cracked of damaged the filter, which would allow it to suck air into the tranny and aeriate(sp?) the fluid, making it foamy. this could also be possible the the ring around the neck of the fileter is damaged or not sealing.... same result, it may be sucking a little air into the fluid.

 

do a filter change again and carefully make sure the filter doesn't get damaged, But I would also see if the clips you mention get replaced, as they might be be part of the problem.... though a deperate attempt might be to use some thin wire to 'hang' the filter.

 

good luck

 

btw, I add a neodymium super magnet to any tranny I service in addition to the original magent, (side by side, that is) With my last filter change on my 92 Lum, the neodymium magent had 75% of the shavings after 30,000 miles of service... my testiment to the fact that it works.

[1990lumina]

When I had my fluid changed about a thousand miles ago it seems to fix most of my problems.

 

My car still slips in reverse when backing up on the driveway like a second after I start the car...I'm gonna say there isn't enough pressure built up in the transmission or something but who knows, after it warms up everything is fine.

 

I'm going to suggest some Lucas tranny fix....a couple of my friend's used it and say it helped quite a bit....

[ns87]

Hmm, crazy K I remember having problems getting the old ring out, so I left it in. I probably cracked or ripped it now that I think of it. I would like to replace the vacuum modulator. Would it only be the 1-2 shift that would be affected? Those are the worst, but the other shifts are still way too firm.

 

1990lumina: I remember when you had yours changed! Did the shifts remain nice even after 1000 miles? Mine usually got "back to normal" within 500ish.

[95oldsVan]

Hmm, crazy K I remember having problems getting the old ring out, so I left it in. I probably cracked or ripped it now that I think of it. I would like to replace the vacuum modulator. Would it only be the 1-2 shift that would be affected? Those are the worst, but the other shifts are still way too firm.

 

1990lumina: I remember when you had yours changed! Did the shifts remain nice even after 1000 miles? Mine usually got "back to normal" within 500ish.

 

Go to any cheap dollar type store and buy some pick tools...I use them to pull out old metal/rubber O rings from trans filters that get stuck up there and if youre putting a new one in on top of it,filter is gonna sit too close to the pan.

 

 

[Crazy K]

It would only affect the 1-2 shift.

 

don't forget, before you replace the modulator, do my test, and turn it so the vac port faces down soi see if it leaks internernally.

 

you may also inspect the vaccum line for kinks, and that the port on the upperintake plenum is not clogged. It is a good point for carbon clog.

 

good luck!

[ns87]

So basically, it wasn't the modulator. It was the cracked vacuum hose coming off the modulator onto the steel line. I figured I might as well the whole assembly, so I did. Problem solved. One day I'll get back down under the car and figure out that filter thing. Crisis Averted!! Thanks everyone

[Crazy K]

[1990lumina]

My shifts are still better then ever....though i've noticed this driveline shake around 60km/h is starting to piss me off....it's a very faintly chugging, papparently it isn't the tranny, it's a drive axle or something