Transmission not fully engaging in some gears when cold.

[infinitysa]

2000 sr5 automatic 150k miles.

I’ve experienced this problem very intermittently for the last few years. When it is extremely cold (< 0F) or the truck has been sitting for an extended period (a month or more) then when I first start up, I can drive, but D and 2 don’t really move the truck unless you rev the engine up quite a bit, towards 2k rpm. R and L work fine. Once the truck travels a couple hundred yards, it’s back to normal.

Since it is rarely that cold where I am, and since I don’t let it sit for extended periods often, this is something I notice maybe a couple times a year.

I changed the trans fluid a year ago and all looked normal, and I had experienced this problem before the fluid change. It is possible my fluid is low, since it is hard to get up to operating temp with an aftermarket transmission cooler. It tends to hover around 145. I have gotten it higher going up hills and check the fluid and I think it is close. Also, 99% of the time, it behaves normally. I’ll try to triple check it soon.

Any ideas?

 

[Hungryhawk]

Regarding your ATF change a year ago-was it a drain and refill, or drop pan wipe out gunk and refill- which gets more fluid except the fluid in the torque converter.
Or did you do a power flush?
Have you thought about disconnecting the tranny aftermarket cooler? Or adding a by-pass thermostat?
Maybe the details will spark some ideas from our experts.

 

[alumarine]

How are you checking the fluid level?

 

[phattyduck]

This has happened to me twice now... based on my research, it is likely a *slightly* sticky shift solenoid (or maybe another part of the transmission)

Putting the shifter in R or L is a mechanical selection of gears, so those are not affected. After it goes correctly in L, everything is back to normal in drive.

I'd be interested in more concrete info though...

-Charlie

 

[infinitysa]

I did the method where you remove a hose from the radiator and run the truck, draining a qt, fill a qt, etc. I can’t recall how many qts I ran through, but it was a lot. I did not drop the pan, but the fluid looked relatively clean.

 

[infinitysa]

How are you checking the fluid level?

Bring truck to operating temp, check dipstick while running. Got it to 160 today and the fluid was at the bottom of the hot range. I am towing over the mountains next week, so I’ll bring a qt of fluid and a funnel to set it correctly.

 

[infinitysa]

This has happened to me twice now... based on my research, it is likely a *slightly* sticky shift solenoid (or maybe another part of the transmission)

Putting the shifter in R or L is a mechanical selection of gears, so those are not affected. After it goes correctly in L, everything is back to normal in drive.

I'd be interested in more concrete info though...

-Charlie

That does sound like my problem. A quick Google found a thread suggesting a low battery could cause shift solenoid problems. In extreme cold and after sitting, the battery is weak. I did jump it yesterday after it sat for two months in the cold. If it is down near 0f, it does crank slowly, so possibly battery?

 

[TheSaturnV]

My 2000 4x4 does the exact same routine, and I mean exactly what you described. I just shift into low and manually run up through the gears and by about 200 feet it's back to normal. Happens so rarely I just decided not to worry about it.

 

[brillo_76]

Maybe I missed it, when was the internal atm filter last changed?? I change my every time I exchange fluid or every 100K at least. Being your towing I drop that fluid change down to 25 or 30K as you are really working that transmission so you need to keep the good fluid in there with a clean screen.

If that's good and clean after 30K miles with nothing in the filter. Then you should be fine. I seen transmission be abused and sometimes it takes two filter changes with 2 complete exchanges to get them back into shape. Its always that fluid and clogged filter that will burn out those clutches. As there are people out there with over 500K plus on the rigs with zero transmission issues as they just maintained their rigs.