My tranny has intermittent issues with searching for a gear to run. I'm mostly concerned that I'm going to be doing 75 and it randomly shift to 2nd or 3rd gear. Is this considered slip? I never had an issue until I went off-roading the other day and got muddy. No water, just mud.. no wrench light or check engine lights. Didn't find any codes either. Some days it's fine and some I'm heading home from dinner and bam! I'm probably due for fluid and filter change, but it I need to replace a solenoid then I'd like to do it at same time. Problem happens regardless if I'm running stock or a tune. Only thing I haven't tried yet is disconnecting battery to reset computer.

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bump... still having issues.. could the TCM have anything to do with it? tried looking for it, to my understanding it's on the inside of the driver side frame rail right below the driver seat, but haven't looked yet to see about a part number to confirm if it's old style or new style.

 

I don't know what old style and new style mean for the TCM. The TCM is part of the PCM, and it is located between the driver's side battery and the fender.

To diagnose this you'll need to be recording data when it happens to see if the TCM is commanding the shift or the trans is doing it on it's own.

 

Old style referring to a TCM that was used in early '08 6.4's. Apparently there was an issue with hard shifting from 1-2, and some fluke other stuff. They created an updated TCM that may have not been to resolve this issue, but it did. I"m not sure where I got the info of it being on the frame rail... maybe I got it on the 6.0 forum...

On a side note, I double checked the fluid level last night, I thought I checked it before already and it was fine, however, I let it warm up last night and check it again, and it seems pretty low.. like it was hitting the cold mark when it was warm... according to the gauge it was warm, but after turning on my tuner and reading the temp, it only showed 120 degreese... and from what i read it should be around 165, which i believe it was I usually see when i have my tuner on. I wonder if that 45 degree difference gave me a bad reading.. I'm picking up a couple quarts of mercon SP on the way home, and i"m going to drive it to make sure it comes up to temp all the way, take another reading, and go from there.... If it's still low, then I"ll add, and if it fixes the issues then I'm going to do a fluid and filter change and be done with it... if i still have the problem, then I"m going to look into it further I suppose.. maybe post on some other forums as well.. including the spartan forum.

 

The TCM didn't change, the software changed. It can be updated without changing the TCM hardware.

The 6.0L trucks have the TCM between the battery and the fender.

The gauge on the dash shows fully warmed up when the trans reaches 50°F.

 

well maybe I'm making up info in my head. No problem, thanks for the info. I"m just going to leave the TCM alone for now, since I haven't ever had any problems with it.

I"ll see what happens this evening, hopefully it's a simple fix that i over looked... I tend to do that now and then. thanks.