a904 lock up?

[joshua dewitt]

i aquired a 1978 ish? a904 with a mild shift kit, supposed to be a lock up for hwy... any way to tell if this is true? by any casting numbers? pump spline visual ( o ring?) that is what the guy told me. but was running a normal converter... don't see any lock up switch on the side. do they have one? or is it all viscus mechanical? couln'd pass up the price.......

 

[TrailBeast]

Here ya go.
Lockup 904's have internal valving instead of electrical controlled converter lockup.

 

[Sedanman]

I have an 88 year lock up and it has a solenoid in the valve body but I think the older ones were in the converter. Does the shaft have teeth of smoothe at the converter end?

 

[TrailBeast]

The valves that actuate converter lockup are one the valvebody in the older ones, and it they are just hydraulic applied.

 

[joshua dewitt]

thanks i do have a lock up trans . and yes it is a lock up converter too. i checked that. this one is rebuilt and supoiavly working, my orignial is a 73 worked but slips. which would be recomened for he street/performance will be running 318 with 340 cam and 3.55 gears..

 

[Sedanman]

You may have to use the linkage arms from your old trans (I had to). I'm not sure on this but many of the lock up's had the lower 1st & 2nd gear set.

 

[dartguy340]

here ya go.
Lockup 904's have internal valving instead of electrical controlled converter lockup.

Correct.....
So there is no way to disable it like you can with the electrical lockup ones.