Sluggish Transmission

My 2007 5.7 Toyota Tundra has developed a quirky habit when the outside temperature is lower than 50 degrees, the transmission fails to change gear ratios properly until such time as the truck warms up. In other words, for the first several blocks leaving home in the morning, the Tachometer reads 2,000 at 30 MPH, but when it warms up, the tach will drop to 1200 to 1500 at 30 MPH. The truck started doing this around 40,000 miles. It now has 53,000 miles and my warranty will expire at 60,000 miles. The dealer tells me that the failure of the transmission shifting properly when cold is NOT an indication that my transmission might be in the need of repair or adjustment. What do you think? What do you suggest?

Since it only started this after it already had 40,000 miles, I’d consider having the tranny serviced. Some fresh fluid just might make the difference.

If it were my truck, I would definitely take it to another dealership before the warranty expires. Also, try searching Google to see if others are reporting the same issues.

A lot of Toyotas will not allow overdrive until the engine coolant temperature reaches a certain level. This is an attempt to speed engine warm up by running it faster in order to reduce warmup emissions.

Check with your owner/operator’s manual to see if it is mentioned there. Also ask a Toyota manufacturer’s rep if that is the case with your Tundra.

It might be that the engine Coolant Temperature Sensor is out of calibration. If the dealer is not willing to check the calibration, suggest that they just change the CTS under warranty. Also check that the thermostat is not stuck open or openning too soon.

Hope this helps.

I didn’t think overdrive kicked in at 30 MPH, but I guess I was wrong.

He says trans shifts into OD when it is fully warmed up. It used to shift into OD at same speed when it was cold.

Sounds normal to me, my Xterra did the same. Did you move to colder region, or perhaps you just didn’t notice it till now?