While cruising on the highway at about 65-70mph the coverter starts to unlock, and lock. Sometimes it stays unlock for a while and then locks again. Does anyone have an idea on what could be causing this, or do i have a bad converter?

 

how long has it done this? is it stock? what mods? my crystal ball is broken.

 

sounds to me like your broke...How are your tranny temps? That is whatt mine was doing when my tranny broke.

 

you could be getting missfires. That will do it.

 

It could but it would about have to be bad enough to feel before it would start doing that.


How many miles? I'm about 100% sure you need yourself a transgo HD2 shift kit and here is why. The torque converter fluid circuit has an on/off solenoid to apply the clutch and a Pulse Width Modulated (PWM) valve to regulate fluid pressure on the circuit. Basically it drops the pressure down going into lock up to make it all nice and soft and slip like so you never feel it lock the converter although it does. Once you get past 55 mph or so you get full line pressure applied to the converter clutch. What happens is after jillions of cycles of the PWM valve is scores the valve body just enough to let fluid leak by and for whatever reason the TCC starts cycling like mad. Thats exactly what mine did and no P1870 dead upon arival DTC either simply because I never let it go that long. The previous owner had no idea it was even happening as it only happed at highway speed and was a 100 rpm or so fluctuation. Anyway the transgo kit does away with that valve, well actually it comes with a new valve that makes the PWM valve no longer in control of TCC line pressure. You get full line pressure at all times to the TCC when its engaged, going to engage, or thinking about engaging. It feels like a 5th gear shift more or less. Get that and a seperator plate and you'll be good to go. At 127,000 miles the seperator plate on my 99 was nearly blown through on 3 of the 7 check *****.

 

it has done this for about 2 weeks. The stall is a 3400 quality stall that was built here locally about a year ago. The transmission was also built here locally a year ago and it is supposed to handle about 550hp.

 

How small is the converter? your misfire tables may need to be adjusted.... Any tuning done.? How a bout a FULL list of mods?

 

10.5 3400 quality stall, my tuning is done by File, my mods are
TR 220/220 56x 56x 114 lsa
lt headers
3in y pipe
gibson caback exhaust
asp ud pulley
e-fans
tune
3.90 gears
auburn posi
10.5 3400 quality stall
built transmission
tranny cooler

 

who did the tune and with what software.....?

 

I just had a converter put in my truck and the tuner who did my tune had to take 100% of the pulse width modulation out of my tune to keep my new converter from doing what yours is doing. He basicly turned the PWM off. This allows no slip when the converter engages and helps keep it locked up.