Is it possible for a tranny to run too cool?

I have a 01 supercrew, 2WD, 5.4, towing package - based on the ScanguageII, which I understand picks up the temp from the valve body (not the hottest point in the system) - the hottest I've see it (summer time traffic jam) was 165* - highway 125-130. Currently, winter temps barely reach 120* at highway speeds a little cooler.

Is this a problem? Cool is better than hot - but, it needs top get hot enough to burn off moisture.

My concern is based in part on what I feel is an increase in slippage between the 2nd to 3rd shift, and some odd feeling upshifts. The tranny was rebuilt 6K miles ago (at 82K miles). The rebuild is under warranty - but, the OD light isn't flashing, and someone that doesn't drive it daily may think it's shifting fine. Better yet - it may not act-up on the 10 minute test drive.

I've considered have the fluid and filter changed to see if that makes a difference.

Thoughts?
Thanks in advance,
Brad

 

I think you have two issues. Whatever problem you have with the shifts is separate from your concerns over being "too cool." The temps you describe would not be an issue, IMO. Mine are similar and 120 is plenty warm enough over a long period to deal with any moisture. Where people can get into trouble is the frozen north and with trucks that are short-hopped all the time but, even then, when have you heard about a trans failure due to that? It's one of those "in theory" things that come up when people get into the minutiae of "what if???" Could happen, but not likely. Would love to see a case history, if one ex

 

Thanks for the feedback Jim - I suspect my "slippage concerns" are also normal based on how the trannys is designed to function. To satisfy the masses - they need to shift not too firm, not too soft - which opens the door to personal preference. Mine would be a bit more firm.

I did try a SuperChip programmer (canned tune), and it seemed only to affect the shifting firmness at 3/4 to WOT, which is not a normal driving practice for me.

Thanks again, and have a nice holiday,

 

Get yourself a performance valve body. I recommend one from Darrin at BC Automotive. Clicky! You can go the separator plate route, but I would go with a full modified valve body!

 

I installed the Superchips program and it firmed up the shifts at all speeds. It also raised the shift points. I don't like either change and I am going to set it back to stock. The 02 5.4 is cammed for low rpm torque and it accelerates quicker with the stock shift points. Stock shifts are also quick enough for my tastes. With the 4x4, it feels like something is winding up when if shifts hard.