Anyone here running it?

I have read forum threads where installers claimed a 1.5~2.0 mpg bump on the hiway with it. Its on my to-do list in a quest to get the Dak bumped up to 20 mpg (or more) on the hiway. The goal is going to be to get the engine strong enough on the bottom end to prevent downshifts on the hills encountered on the way to work. Some of those there is no getting around it, they are too steep & long but the others, yeah I think they are do-able.

Would like to hear 1st hand experiences from anyone who has done that mod...

 

In case you weren't aware, the late model 2nd gen Dakotas and Durangos also have that TCM. Anything with a 545RFE. Just in case you go junkyard diving....

 

Thanks, was not sure if that was a direct swap or not. I know DC changed things up at some point and went to a single controller for both engine & trans, just not sure when.

... and oh yeah, will be junkyard diving for sure. Going to hunt down a different center console and floor console to accommodate a manual shift transfer case. Will swap in a NV242/NP242 (?) a some point. IIRC the '98/99 Durangos have that setup.

 

Picked up a "1905" JTCM last week. Sitting on the shelf waiting its turn.

 

Install done, interesting observations... while researching this mod, not one person described what actually is going on. So... here's what I see

Speeds ~<40 & up mph... trans shifts into highest gear (5), TC unlocked.
OD off with above condition... Trans shifts into next lowest gear (4) and locks TC.
Seems to stay that way until sufficient load is present to cause a downshift into 3rd, with the TC locked... (need to double check this but its what I recall) Or enough speed is there to upshift into 5th

Hiway speeds... trans does not downshift easily on a grade, appears to hold 5th (need to double check this) with TC locked (this is where that bottom end torque comes into play I spoke of in the MPG thread)
After enough load/throttle input, it will downshift into 3rd (unclear if the TC is still locked or not, too much traffic).
@60 mph, 1600 rpms, a 300 rpm drop.

Truck = 2002 QC 4x4 running 265/75-16 tires.

Jeep TCM mod

 

Update... Ok so the brake problem is behind me, last tank tanked and gave 14.5 mpg. Not surprised with the caliper locking up after the pad install. Tank re-filled for another best effort to & from work. (previous best was a 17.0 but that was during the t-day week off)

What I am seeing now on the drive into work is it indeed does not want to downshift easily on the hills and it does loose some mph while not in CC. It does have a little bit of a hard time accelerating on the longest hill in 5th gear. The bonus that I am now seeing is there is a scenario where it appears I am in a gear that is turning at 1500 rpms with the TC unlocked doing something like 30~35 mph. This is going to help city mpg's if I can figure out how I got there. How this will help is under coasting conditions, getting back into the throttle and having the drive rpms at 1500~1600 or so. Need to figure that one out. (this is an ECO drive style thing...)