this may be a stupid question that i should know the answer to, but just want to see some other opinions. do most of yall lock out OD all the time when your under 50-55 mph? can doing this save the tranny some? ive always heard people say mixed things about doing this so i thought id get a definite answer thanks for putting up with a question this simple<br><br>(i think my tranny is goin to go soon anyways so i just want to get as much outta it as i can)

 

If you're woried about the tranny letting go, you might do that. My tranny is slower to lock up the TC now that I have a PM# on it, but I always get that sucker in OD and lock the TC ASAP, to increase fuel mileage. As long as it doesn't slip I have no worries.<br>Some talk about &quot;lugging&quot; the engine. I don't really subscribe to that. The diesel is MADE for low RPM torque, so the lower the RPMs in high gear the better, as far as I'm concerned. Some also say that when &quot;lugging&quot;, the engine is putting out so much torque it will slip the tranny, so like I said before, as long as the tranny doesn't slip, I'm happy.<br><br>Chris

 

the &quot;lugging&quot; u mentioned is exactly why i posted this question. i few days back i remember reading a thread about just what was considered lugging the engine and i wanted to make sure i wasnt hurting anything. thanks for your help

 

Lugging the engine is anytime you can not gain RPM's...like when traveling an upgrade and you can not grain any more speed then you would be lugging the engine

 

To answer your question yes lock out of overdrive below 50mph. ;D

 

I keep mine locked out till 60. Even if I'm cruising at 55, I'll leave it locked out. Believe it or not, I actually get better gas mileage and lower EGT's crusing at about 2100-2200 in third gear. Go figure.