Hi,

Is it possible to change the shift solenoids with the transmission in place?

I don't care if I have to open the oil pan or something, I just want to change them.

1st gear slips like crazy when in "D" when cold. Driveable if forced in 1st with shifter (slips, but less). Problem goes away after 3-4 stops and some heat, but is still dangerous because I have to have acceleration when going out of work, road is crazy fast and people don't give a F.

Numerous discussions led to think the solenoid might be malfunctionning. So I might change all of them if I going to go in there.

Thanks a lot for any and all feedback/answers!

In order to service any of the solenoids on the transmission, the side cover must first be removed. In order for the side cover to clear the trans valve body and car frame, the trans has to be lowered so far. Usually this involves either dropping half the sub-frame(depends on what kind of car you have, and this is an important piece of knowledge any car forum needs to know) or dropping the engine/trans halfway out the bottom of the car.

We also need to know how many miles are on this car, any and all mods done to it, vehicle maintenance history etc.

260000 kms, no mods. Changed the fluid at 220000 kms. Wasn't burned when I changed it but unable to know if/when it was changed before that.

As for overall health, starts steadily (4-5 audible "cranks") no matter the temperature, runs as strong as I think it'* supposed to. Shifts VERY smoothly (as in surprisingly smooth, much smoother than a lot of auto trannys I drove) once settled.

Changed heater core and water pump recently, this renewed my love for the car (how awesome is it to not have to worry about overheating AND have hot feet!) and I'm willing to do what there is to do to keep it. Car has been doing the 1st gear slippage for a year. It got better when summer came around, but as soon as temperature got milder it started doing it again.

It never overheated btw, I was just worried of it happening.

But no matter what, it cannot be TOO bad to drop the subframe if I can get proper equipment access. How bad can it get? Disconnecting a few hoses and wires from the top? I'm pretty sure it'* the solenoid, most articles and people I spoke with point towards that.

Also, what year is this? (please take the time to put your year, make, trim, engine etc in your signature that way people will see exactly what it is your talking about)

Have you smelled the trans fluid recently? If the fluid is darker than usual and smells burnt, I'm thinking you have toasted clutches.(which means a rebuild).

If the vehicle is like 96 or newer, the PCM should be able to detect faults with the solenoids themselves. But its unable to detect a blockage in the valve body I believe.

We do have a resident trans guru here SGP358, Danthurs has some good knowledge also, hopefully they should chime in soon.

Again, this depends on what kind of vehicle you have. Some platforms(bonnevilles) have a sub-frame that can be split in half allowing the trans to be dropped through the bottom. Others(Impalas I think) have a non-splittable aluminum sub-frame which means you would have to drop the entire frame/engine/trans as a whole.

I'm not going to say for sure its a solenoid, or premature failure of the 1st clutch pack, but considering the complexity of a FWD transmission, slippage could be a number of things causing it. Only way to say for sure is to have it taken to a transmission shop for diagnostics.

Well, implying the level of complexity for any maintenance and costs of professional diagnostics, would it be reasonable to simply try to find a lower milleage tranny and replace it as a whole? (I don't have the original 4T60-HD, realised it when I changed a CV shaft and the one in the system was too big, had to use one from a SE, would probably get another as they are much more common and I wouldn't have to switch to the bigger CVs).

Also, the problem resolves with heat and a couple stops and the transmission doesn't slip at all after, does it mean something or it'* very random? (I'm really profane with auto trannies...)

Oh and also, thanks for your previous answers! Forgot about that like we'd already be an old couple XD

Wait, are you running a non-HD 4T60-E on a L67 engine?

Yes, not my choice, some previous owner did it. Realized when I had to change a CV shaft. Is it that bad? I heard only the differential was stronger but no other transmission part.

Even though, it musn't be quite easy to find a good running, low mileage 4t60-hd :-*