Help,
I just had the fluid and filter changed in the transmission (A340H) of my '92 4runner. Now when the truck is cold the transmission shifts really hard and the rpm's seem to be revving much higher than seem necessary. The problem disappears when the engine temperature comes up to normal. Not showing any trouble codes.
Wondering if anyone has experienced this problem and curious if there is a port for testing line pressure?
Any input would be appreciated.

 

My A340H seems to shift a little hard too, though it doesn't seem temp related. It feels like it shifts twice. First i feel a little bump and the r's drop slightly (i don't have a tach) then a second later the rpm's drop some more. One other curious thing I've noticed. When I first start the truck, it takes a good 3-4 seconds for the truck to move, as if it is slow in building up fluid pressure. I would like to know if these are just minor incoveneinces of a high mileage tranny or signs of a more serious issue.

 

You're both using Dexron III or IV rated fluid, no?
Not Dexron V or VI, right?

 

I'm using Valvoline Max-Life dex/merc.

 

Correct fluid. Mine is totally temperature dependent and when it shifts it knocks your head back even when shifting in reverse from park. Tried the ECT button on and off, no difference. Tried the Overdrive on and off, no difference. My mechanic is really interested in testing line pressure. Is there a port?

 

same with mine, it feels like the wheels kick when i go from reverse to drive and shifts sporadically while driving. i thought it just sucked.

 

any new answers here ???

 

Thats normal for the A340h, the hard shifting when cold and at 1st start up......mine has always done it. And my buddies '93 has done it ever since he bought his in '93.

 

I was thinking your line pressure may be too high also. The port is located on the passenger side of the tranny. Just in front of the ID plate you will see a bolt. That is the pressure port.

 

I just had a new torque converter installed and now I am experiencing harsh shifts when cold. once things warm up seems better.

 

Line pressure is controlled by the cable going to the throttle. You can loosen it off a tad to let the transmission shift smoother.

If the transmission likes to rev really high, and then shift hard, I would take a look at how the throttle position sensor is adjusted. The transmission ECU shifts based on input from the TPS. If it's mis-adjusted, it will shift too early/late.

 

2024 but advice is still new to me. I will try loosing the cable. Mine shifts harsh cold/hot, in or out of overdrive. Sure would like to figure this out.