firetoy

i have a 92 cummins with the 727 if i hit the over drive button off does that mean the tc is locked up?

mhuppertz

No, they are not the same (although it kinda feels the same though). Lockup is when a clutch in the torque converter engages, causing a direct drive from the engine to the trans input shaft. It's that same as letting the clutch out on a standard trans. Overdrive is when the output shaft of the trans spins faster than the input shaft. The later autos have lockup and overdrive.
Does this help?

firetoy

yeah thats helps. is there anyway to get the tc to lock up?

mhuppertz

Quote:

Originally Posted by firetoy

yeah thats helps. is there anyway to get the tc to lock up?

Not with your 727. You'll have to go with a later model that has provisions for a lockup because lockup trannys are designed that way. If you blow up the 727 you might want to switch to a 46RE or 47RE lockup model. The auto guys will be able to guide you on this.
Mark

reference: http://www.transmissioncenter.net/dodge.htm

Cowboy_Customs

The early A518 is a non-lockup transmission, but with overdrive, the 94-95 47RH (hydrolic), and 96+ 47RE (electronic) are lockup overdrive trannies.

By simply pushing the OD button in your rig, your just downshifting.

U have to switch to a different transmission to get lockup, and more lesctronics I believe as well, the 94+ trannies have like 3 plugs, versus 2 plugs on the A518.

firetoy

well when i burn it up then a will do a swap. in the mean time i will install another tranny cooler.

mhuppertz

Leave the tranny cooler off and it will burn up faster!