Thread: Auto Trans: Several Symptoms

At those temperatures lock up in fourth will not take place until the transmission and engine have reached full operating temperature, maybe three to five miles. Could be more as I am not used to those low temperatures. Also of importance is in Drive there is no lockup in third going through the changes. That only occurs when driving in Third. It may be that what you are experiencing is normal.

Nick

Originally Posted by Pippin

At those temperatures lock up in fourth will not take place until the transmission and engine have reached full operating temperature, maybe three to five miles. Could be more as I am not used to those low temperatures. Also of importance is in Drive there is no lockup in third going through the changes. That only occurs when driving in Third. It may be that what you are experiencing is normal.

Nick

Correct, I will have the shifter in 3rd and I get lockup in 3rd. But 4th, may be OK, I have read other posts where cruising speed at 65-70 in 4th will put you at just over 2200 RPM. Maybe I get lockup so quickly after it changes from 3 to 4 that it's unnoticeable. From everything I have read, the trans isn't shifting up through all of the gears early because of perimeters in the computers. But I always allow the vehicle to get up to operating temp before I begin driving and if in D-drive, 1) Gears will not change up from 2 if it's under 35F, 2)will not change up from 3 if it's under 40F, 3) will not lockup in 3rd gear if it's under 40F and not changing up to 4th.

If I know it's not going to shift through the gears I stop in a parking lot and reverse for a bit. Put it in park for a couple mins. Mind you, coolant temps have been at 194-196 since I started driving. Then I will drive it forward and reverse again. Get back on the road with shifter in 3rd. If gears shift up to 3 and TC locks up, then I know that when I reach the highway in 1/2 mile I can put the shifter in drive and it will change through all gears accessing the highway.

If ambient air temps Are above 60F around the clock, I have none of these shifting problems. I allow the engine to warm to operating temp and gears change 1-2-3-4 with no hesitation. So could this be something in the computer? Fluid pump? Other such as MAF? No fault codes by the way.

If you have correctly filled the Transmission by the book on the fluid changes I wonder whether this may be a thermostat issue. Perhaps Discorevy could shed some light on this or anyone else who might operate in cold conditions or have some ideas?

those symptoms mostly match for an undefilled transmission with too much cooling because of a sticking cooler thermostat.

they will be made worse if your maf/map are out of kilter and if your TPS is dicey or you have a remapped ECU.

as an experiment, on a cold morning blanket the front of the car and see if that makes it behave more like it should if it does then that points you into the right direction.

while its very cold you can getaway with adding about another 400ml of oil to the trans to encourage it to warm up faster OR you can preheat the underside of the car by putting a car blanket over it and putting a 1000W flood light under the engine at the back of the sump.

What type of atf are you using ?. Have you done a stall test ?.
Ditto about correct level , you need to drive it as well as having the engine at operating temp as the ecu calculates both parameters before letting lock up happen , the change from 3-4 is harder to pick than the change from 4th to lock up
Pippin , I know Albany gets referred to as north Antarctica sometimes, but it's not that cold :-)

Originally Posted by Pippin

If you have correctly filled the Transmission by the book on the fluid changes I wonder whether this may be a thermostat issue. Perhaps Discorevy could shed some light on this or anyone else who might operate in cold conditions or have some ideas?

I have started threads regarding this issue on US forums, and although others have commented having similar issues, nobody has ever confirmed source or possible resolutions

Originally Posted by discorevy

What type of atf are you using ?. Have you done a stall test ?.
Ditto about correct level , you need to drive it as well as having the engine at operating temp as the ecu calculates both parameters before letting lock up happen , the change from 3-4 is harder to pick than the change from 4th to lock up
Pippin , I know Albany gets referred to as north Antarctica sometimes, but it's not that cold :-)

ATF is Valvoline Dex-Merc "MaxLife" full synthetic. before that I had the standard Valvoline DexMerc. No stall-test, I have never heard of that. Level should be good, always do it by the book. 95% of the time the truck is at full operating temp of 194 F before I begin to drive it. I also added 3/4 bottle of LubeGard Red.

I see the problem...

just because the engine is reporting 194 deg f does not mean the radiator is, the thermostat prevents excess cooling of the block, the auto cooler is (and this is general to cover more than one vehicle type) either in front of or internal to the radiator and is not linked to the engine temp.

if the auto is coming up as low temp it wont play normaly until it does, if you're reading the engine temp its not indicitive of gearbox temp.


A stall test is brutal on the oil and driveline especially the torque converter dont do it for long but basically...

get it all warmed up load up the brakes, lock on the park brake stick it in D and bury the noisey pedal, the max RPM you hit is your stall RPM. (doing this is also a brutal but effective way to very quickly get an auto up to temp but you dont need to bury the boot, just hold 1500rpm or so for a few minutes...