Auto Torque Convertor Lock-up

[sacred cow Member Find all posts View Profile Close sacred cow]

Hi,

How can I be 100% sure that the torque convertor in my D4D has locked up? Is there a signal coming out of the gearbox that I can monitor?

Regards
Glenn

[Fazza Senior Member Find all posts View Profile Close Fazza]

Glenn,
The best indication or signal that you are in overdrive is the rev counter.

It will continually be in & out depending on load,speed & right foot. :wink:

Cheers,
Fazza

[mototrim Advanced Member Find all posts View Profile Close mototrim]

Fazza do you know at what speed the new 5 speed auto locks up as my SR5 D4D 4 speed did at about 85kms?

[Fazza Senior Member Find all posts View Profile Close Fazza]

mototrim,

I'll have to check it out in the next day or so, from memory it's about 60k's but a slight bit of pressure on the loud pedal & it's down to 4th.
The higher the speed or less load the more it will stay locked.

Cheers,
Fazza

[lawrance Senior Member Find all posts View Profile Close lawrance]

Interestingly, if you are cruising along with the torque converter locked up and take your foot off the accelerator, the 5 speed auto gearbox unlocks the torque converter and allows the revs to drop. But if you put your foot back on the accelerator, it allows the engine to rev up to the speed of the gears and relocks the torque converter, assuming you are not putting your foot down hard.

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

Interestingly, if you are cruising along with the torque converter locked up and take your foot off the accelerator, the 5 speed auto gearbox unlocks the torque converter and allows the revs to drop. But if you put your foot back on the accelerator, it allows the engine to rev up to the speed of the gears and relocks the torque converter, assuming you are not putting your foot down hard.

Yep this is a fuel saving feature.....that I hate a lot as it effectively allows the car to run-away down a steeper hill as the engine is disengaged from the drivetrain especially if you have the cruise engaged.