TCC Slip numbers via the Torque app

{tpc}

Original poster
Member
Jan 22, 2014
359
Does anyone know what one should be seeing on this? I have it loaded up on my app, but it moves around quite a bit. Just trying to figure out if everything is working right. The transmission does not seem to be acting funny (despite the fluid leak issue I am working on now), and the only time I recall seeing low numbers on this is up at highway speeds, which kinda makes sense to me. But I thought I'd ask here to confirm. :smile:
 

thor124

Member
Jul 23, 2013
19
{tpc} said:
Does anyone know what one should be seeing on this? I have it loaded up on my app, but it moves around quite a bit. Just trying to figure out if everything is working right. The transmission does not seem to be acting funny (despite the fluid leak issue I am working on now), and the only time I recall seeing low numbers on this is up at highway speeds, which kinda makes sense to me. But I thought I'd ask here to confirm. :smile:

Here's what I've observed on that subject while using Torque:
1) While stopped and in gear, the TCC slip should be close to the engine RPM.
2) When moving, but not in 4th, the TCC isn't locked, and you should see a little bit of slip. In the range of a few hundred RPM if i recall. A bit more while accelerating
3) When moving, in 4th gear, the TCC may be commanded to lock by the TCCM. If it's locked you should see minimal slip, well under 100 RPM

I'm sure someone else will contribute, I'm not an expert on the subject, but wanted to share what I've observed.
 

Harpo

Member
Dec 4, 2011
411
Sweden
I agree with that.
There are very few times I've seen zero on that for a longer period of time.

Maybe for about a few minutes on a very level road with some tailwind.

But normally it would be around 10-30 rpm when locked maybe a little higher 50-150 rpm sometimes. It's hard to tell why the variations are there, but it's a lot of parameters that controls that I guess.

I've also seen minus rpm when engine braking quite often.
 

{tpc}

Original poster
Member
Jan 22, 2014
359
Ok, cool, thank you all for the explanation. It seems to be working as described, but at least it will give me something to look at later on, now that I know what it means.
 

AtlWrk

Member
Dec 6, 2011
674
Out of lock on the highway I'll see between 150-250 slip depending on load. At lock mine goes down to 0 (+/-3rpm) but I have a shift kit that eliminates the PWM function of the converter clutch lockup. I do recall reading that the clutch may be programmed to allow a constant few tens of RPM of slip at lockup to ease transitions in and out. This is all controlled by the PCM so differences in programming may have different results from year to year.
 

santon

Member
Jun 3, 2020
104
Israel
Sorry for reviving this old thread. At what speed at 4th gear the torque converter should be normally locked?
 

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