Allison Torque Converter Unlock [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: Allison Torque Converter Unlock


kbstinky
11-19-2003, 11:09 PM
Recently had the Banks Exhaust Brake and the cat-back Monster Exhaust installed at Banks on my Dmax/Alli.


I want to say that prior to installation in NON T/H mode the converter would drop out at 19mph. It now drops at 49 mph. Unfortunately given my advanced CRS (can't remember sh_t) I don't remember exactly if it was dropping at 19mph.


The brake works like gangbusters in t/h mode, and would sure like to have the advantage in normal trans.


Does anybody know what theirs drops out at???


The way it is now, I freewheel from 49 on down, and I don't remember doing that.

CADman_ks
11-19-2003, 11:14 PM
Mine does that somewhere around 15MPH.


on edit: I do NOT have an exhaust brake. My truck is totally stock.


cadman_ksEdited by: CADman_ks

a64pilot
11-20-2003, 08:53 AM
Once the trans is warmed up I think mine locks at 52 mph. I think at O throttle if it's not using grade braking it remains unlocked on coast down at speeds less than that. I also have no exh brake though.

Ray403Dmax
11-20-2003, 10:22 AM
Yep, for me it locks a little over 50mph.

Horse Trainer
11-20-2003, 02:16 PM
In T/H, I believe that the TC is locked in 2nd gear and up (I'll try to see at what mph it locks - it does hold until about 15). In regular, TC only locked in OD. I too have a Banks Brake, and in situations where I need it, I engage T/H. Even if the TC does not free wheel on decel out of T/H, the slip will heat up the trans fluid in a hurry.

kbstinky
11-20-2003, 11:21 PM
Thanks, but what I am really looking for is the deceleration side.


When you are going 65mph, and let off on the throttle, at what speed does your converter UNLOCK. Mine does it at 49mph and the engine drops to idle with NO compression at all. The only time I get compression is in T/H mode, whether Banks is on or not.


I beleive that before I put in the Banks Exhaust Brake I had compression in Normal mode all the way down to 19mph.


Thanks for the input.

Ray403Dmax
11-20-2003, 11:44 PM
I don't have an exhaust brake...


When in normal mode (not in T/H) mine unlocks around 49mph. But the rpms never drop to an idle, instead the rpms raise slightly as the torque converter slips.