Transmission Questions.

Tank222

New member
Feb 17, 2010
337
0
0
Frederick,MD
So I have a built trans with a precision ml converter. I think the truck feels like shit unless the converter is locked. Like it just blows threw the rpm range with out making any power. It just doesnt pull. Can you tune the converter to lock up earlier, or should I just drive around in tow haul mode all the time.
 

Sharks06LLY

New member
May 15, 2010
115
0
0
Tampa Fl
idk that sounds wierd to me especially since its a big dipper trans, maybe has something to do with gear ratio from ur big tires?
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
Log your converter slip rpm during an acceleration run when it feels like its blowing through the converter.
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
Once you connect to your tcm, select "validate pids", then select input rpm, turbine rpm, and converter slip rpm. Converter slip rpm is simply a calculation based off of input rpm, minus turbine rpm.
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,681
232
63
Fullerton CA
He is not complaining about converter slip as he stated it feel good in T/H. Reading converter slip will only rell you when the clutch in the converter is slipping.
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
He is not complaining about converter slip as he stated it feel good in T/H. Reading converter slip will only rell you when the clutch in the converter is slipping.



He is complaining about it feeling "like its blowing through the rpm range", like the converter is just slipping.

Reading converter slip when the clutch is applied will tell you if or how much the clutch is slipping. Reading it when the clutch is not applied will also tell you much the converter is slipping. Obviously it should have slip when the clutch is disengaged. This is hwy when you come to a stop in gear the engine doesn't die. But if he posts up that the converter is slipping 1500-2000 rpms when the clutch is no applied, then he has found his problem.


The only thing T/H eliminates is the fluid connection part of the converter because it is locked solid. If it feels good in T/H that means the trans is holding, and once the converter clutch is applied, it is also holding.
 
Last edited:

Tank222

New member
Feb 17, 2010
337
0
0
Frederick,MD
I'll log that tomorrow.
If i'm just going down the road at 50 and smash it, it feels like its blowing through the rpms, like its not making power.
If I go down the road at 50 press tow haul and manual down shift say into 3 with the little lock button on my screen next the the gear indicator and smash it truck feels awesome.
 

LWATSON

future trans limpers
Jul 30, 2008
2,587
1
36
55
Scotland Neck NC
Mine does somewhat the same thing. At partial throttle it will just rev and slowly accelerate. If I go the rest of the way to the floor the converter locks and she goes like hell. It almost feels like I'm just overpowering the fluid coupling of the converter like when a boat prop cavatates "spelling" in the water.