My new commute to work is mainly city driving on most flat ground... posted speed limit is 35.. everyone drives 40-45.... my tranny constantly shifts around 40-45 into overdrive...this leads to bad fuel economy and wear on engine (CTD)...

I found the link below to manual engage the torque convert with a swithch... easy install and I would assume (under light driving conditions) that this mods wouldn't damage the drivetrain...and it would improve fuel mileage... I don't imagine I would use it while towing.. but what do you guys think...?

http://www.tstproducts.com/Torque%20...p%20Switch.pdf

 

Just turn off O/D while in town.

There is also a mod that will have O/D default to "Off" at startup, so, when you want to use it, you push the button.

 

+1......

 

no... I'm talking about having the ablility to lock up your torque convert.... not limiting what gear your truck will go in... with this mod you'll be able to lock-up the TC in 2nd gear and stay locked throw 3rd and 4th...

turning on/off overdrive doesn't lock the tc.. it limits the gears to only 1,2,3.. not 4th

 

I believe TC locks up before OD. If you read the doc you linked, it talks about 3rd to 4th. 4th is OD.

 

TCC locks in third, but, so far as I know, not the lower gears. In all reality, I don't think it would really be good for the trans to be locked for the 2-3 shift..... 3-4 isn't as critical as the O/D unit is completely separate from the rest of the trans.

 

Yep. After shift to 3rd, settles in and pressure reaches ce.rtain point (i don't rememebr what that was) and then TC locks up. TC must show locked to hit OD

 

The torque converter will lock in 3rd but doesn't unless O/D is locked out.
At least in my 96 it's that way.
Left to do by itself it goes from 3rd to O/D then lock up.
When O/D is locked out and converter is locked and I push the O/D button so it will shift into O/D the converter unlocks, the shift to O/D then takes place and if the speed is great enough the converter locks up.

 

You are correct sir! I suspect that this method of operation is why folks get better mileage about town with O/D disengaged.

 

1st, 2nd,3rd , tc lockup, OD. (do not drive around town with OD on) Although the 47re is better than the 46re, the same higher temps are no good.. When you get in the truck and start it, turn OD OFF straight away. Only engage OD if over 60, 65 mph. Install a temp gauge and you'll know right away why I say that.