Hey everyone, so this has been pondering me for quite some time now.

So, it's cold and snowy here now in upper IL and my transmission is being temperamental. Once in a while the trans will start slipping when shifting to 2nd, and 3rd. Then, weeks will go by when it doesn't do it, and now just recently it started doing it again.

* So I found that starting from 1, getting to 20~mph letting off, switching to 2nd, getting to 4045~mph going to 3, and then D, the transmission doesn't slip.

I did a test too. Having it shift gears by itself usually takes about 2.5/3 seconds when it's slipping and you can definitely hear and feel it slip (I cringe when it happens).

Changing gears by myself (see two paragraphs above *) it doesn't slip and the gears change instantaneously as they should.

Now the tranny drives fine; No clunks, jerks, whines, whirs, etc. It also seems like 2nd doesn't have as much "oompf" as it usually does. It could just be the dense, cold winter air that makes the pedal seem "solid" to WOT, or it could not be.

I'm thinking of changing the filter, and transmission juice out tomorrow on my way back from finals, or later on in the day.

I don't think my tranny is going, but could just be a simple juice & filter change.

What do you think?

02 MC LS
oil changes every 3k w/Pennzoil and Pennzoil High Mileage both with active cleaning ingredients.
117k~ mileage.
Still puts you in the seat.

 

How do you know its slipping? Ots only during shifts? Is their a grinding and rpm fluctiation? What is the exact symptom when you shift? You say slipping but I'm just curious what exactly its feels, sounds and looks like on the rmp gauge.

 

Because it usually shifts at 2500rpm at 25mph. It makes the sound at 2500rpm-3200rpm like someone is in 1st gear (towards the end of the 1st gear) and doesn't shift to the next gear. Know what I'm talking about? THEN, it finally rolls over to the next gear.

No grinding, no fluctuation in the RPM's that I notice.

It's really hard to describe. I'll post a video the next time it does it so you get an idea.

 

Does it feel like its shifting hard? If not check the fluid color and have a trans shop run codes, if your shift times are maxed out will store it in the pcm with no cel. So if I'm getting this right it just sounds like its going higher in the rpms? No other malfunctions? Just a higher shift point?

 

No, it shifts perfectly fine.The fuild is a dark cherry red, but that's why I might change it tomorrow.

I had to replace my battery earlier today, because it was below 12v. So, the car had no battery in it for 3.5hrs as they were charging it. I left with a new one anyways. You don't think that could be it do you?

 

No that doesn't make sense, and the fluid seems ok. Still doesn't hurt to change. Normally slipage would cause a lot of errors. This seems like shift lag, which could be cause by slipage but also by to thick fluid. Do you have any trans-fix products in your fluid?

 

I'll check it tomorrow and see what the fluid color is. If it's anything but a red color, i'm going to change it.

I do not have any trans-fix products in there. ( I myself did not put anything in there since I bought it back in '08)

 

In general, the trans fluid and filter should be changed no later then every 100,000 miles.

I'd say give it a shot and see what happens. It's worth a try. The fluid ages and can cause weird issues.

On a side not, I know at least with my wife's 3400 Impala (it's like a 4 door Monte), the trans intermittently would bang into gear as it up shifts. I increased the line pressure settings on the PCM, no more issue. See the post I have in the link below for more info:
https://montecarloforum.com/forum/pr...73/#post549403