I've got a '97 ram with a 5.2 and 3.55's running 35" tires. The thing is pathetic on the highway unless i'm going 130+ km/h; downshifts way too often and forget about using cruise control. At normal cruising (110km/h) I'm revving like 1600rpm which is good only for flat land. My remedial fix for this for the time being is taking O/D off, however this kicks the tranny into 3rd gear where I rev around ~2700rpm which is a bit too high.

I'm wondering if anyone has any info on how to disable lockup and keep the tranny in 4th gear. Everytime I drive the thing I am perplexed as to why the tranny immediately goes into lock up after doing a 3-4 shift. it's as if 4th gear is completely useless. However, sometimes I can hold 4th for a few seconds by doing some skinny pedal trickery, and end up revving around ~2200rpm which is where I would like to be revving on the h-way.

And before anyone says it, 4.56's are in future plans but not until at least next summer when I'm back home and have the tools to do it myself.

 

TC locks up before OD. A fix for the problem...put correct sized tires back on it or regear.....

 

The shift points on these trucks/transmissons are pretty stupid anyway.

I tested my truck, it can do 70mph in 2nd gear @ 4k, and yet if you let overdrive do its thing you're in od by 55. Way too soon.

 

indeed, so why does turning off the O/D switch kick to 3rd with TC locked? This disengages the overdrive clutch PLUS drops a whole gear... it appears to me that I simply want to disable whatever controls the overdrive clutch in the tranny.

Anyone know 46re's well? I thought there was an 8-pin power connector going into it that controlled solenoids and such.

 

4th gear is OD. 1st,2nd,3rd,TC lock up, 4th(OD)

Any how, the tires are the problem. Turn the OD button to off until you get the better gears, maybe the tranny will last that long if you do so. Its being beat to hell with those size tires. And have you inspected the plenum? Or read the plenum stickie?

 

+ + + Good posts above for sure! The reason for the TCC is it's supposed to improve MPG and reduce the transmissions fluid temperature aka maximize efficiency. The TCC engages in fourth and in 3rd when the O/D is turned off...And if this is incorrect someone will jump in and say so, believe that! Good read below, thanks to merc225hp

http://www.4x4wire.com/dodge/tech/tc_lockup/

 

When OD is turned off, there is NO fourth gear. And if OD is on, the TC is already locked in at 3rd gear. It just simply goes into OD(fourth).

 

i don't think that is so. I get 2 seperate but closely spaced rpm drops when cruising and put the O/D back on. First rpm change drops 3-400rpm (this is where I want to be) then the next drops the around 800rpm.

As per the manual, TC will lock in 4th. It seems to me that the tranny should shift to 4th (OD), drop the rpm by a larger amount, then lock up and drop a smaller amount. my truck seems to be doing the opposite, which doesn't really make sense to me.

Can anyone clarify what's happening in that shift? Thank you