Thread: torque convertor not unlocking 4 speed

that'll do it for me!

<div class='quotetop'>QUOTE</div><div class='quotemain'>Stall and lock are two different things.
The 3.9 converter stalls at 1500RPM. ie the slip reaches a minimum. or the stator and rotor are travelling at the same speed +-10%.
"stall" converters for some reason are only called that in OZ. Everywhere else AFAIK they are called "high stall converters". This is where the stator and rotor are a different design so that the speeds only equalise at say 2000RPM.
The pupose is to give more torque multiplication off the line, as the slip is a "lower gear" and to allow engines with poor low down torque because of a big cam, to jump off the line better, and in some cases to allow a modified engine to idle in drive

The lock is a clutch which is engaged to physically connect the stator and rotor in the torque converter to eliminate slip and give better fuel economy. In a hydraulically controlled auto like a 4HP22 it is activated by the governor( I think) , while in electronically controlled transmissions it is controlled by the ECU and can be varied , and even locked in low ratio etc to give better braking.
I am not too expert on Autos so if anyone thinks this is wrong or can give a better explanation , please do.
Regards Philip A[/b][/quote]

thanks again master of things techinicall

phil

Well , I just had a look at the manual and am none the wiser.
I do not think you can change the lockup speed, as to lock up at a certain speed it must be controlled by something that senses revs of the transmission. The only thing that I know does that is the governor.
Thats the logic. whether its correct is another thing.
I suggest you talk to a ZF specialist shop, or even ZF themselves. They have a distribution centre and rebuild centre in Sydney.
Maybe if you changed the governor, but yours would be 2HP22 and the 3.9 transmission is a 4HP22, but I think the governopr would be similar.
Regard s Philip A