Torque Convertor Lockup

[2000superduty]

I assume that the transmission (4r100) will not lock up until it reaches a certain temperature. I noticed that ever since i have changed my transmission fluid it takes longer for the tranny to lock up. How long does it normally take for this to happen? When i turn out of my driveway its a two lane road with no stops and it takes roughly 4 to 5 miles before it locks up. Does this sound right or does it sound like something is wrong?

[Greenman01]

Their are many factors that play a role in TC lock up. Throttle position, trans oil temp, governor pressure and modulator pressure to name a few. Do you have trans oil temp guage? Perhaps your old oil was broken down enough to heat up much quicker

[jesilvas]

Usually it's a temp issue in the morning. But yes, there is a certain temp for it to reach. Less than 100*F, I know that much. I let mine idle in the morning anyway so the trans heats up enough before the motor does.

[2000superduty]

Yep, i have a trans temp gauge. When it's cold out it barely moves. Sometimes depending on how cold out it is, it doesn't move at all on my 15 minute ride to work. I was thinking the same thing about the tranny fluid being broke down and now the trans is running cooler but i wasn't sure if that was possible.

[jesilvas]

Down to 46 this morning and truck sat from 545 yesterday to 730 this morning. Took about 2 miles of 2k rpm to lock up

I made my Samsung SGH-I997 send this.

[Greenman01]

I don't think it is anything to worry about. If it wasn't locking up then i would worry.

['01SilverBullet]

Its supposed to do that, to help warm the trans oil up

[2000superduty]

Just wanted to make sure. Thanks everyone for the help.

[zpd307]

good information to know. i have noticed that odd behavior, just never put too much thought into it.