2004 V8 Transmission Lockup/Unlock

[Harry Wiley]

I have a 2004 V8 4R with 44,000 miles. It is a really great vehicle, but:

When crusing down a level road at moderate speeds, it will shift thru the gears until the transmission locks up in 4OD.

After a short time, the tach will increase 100-150 rpm and stay there indefinitely. If I shift out of OD to 4th and back, the transmission will go back to the original lower rpm for a while and then sooner or later increase again.

I think the torque converter lockup is being unlocked for an unknow reason and will not lock up again until it goes thru a shift.

I suspect a sensor somewhere is not satisfying all the conditons for lockup, but nothing will change the unlocked condition except a shift sequence.

What now? I told the local dealer service advisor about the problem and got the "deer in the headlights" look. No one at the dealer knew that the transmission locked up at cruise!

Thanks for your help.

Harry

 

[khaug]

Our '03 LTD 4WD V8 will occasionally do what you describe. You need to recognize that you're in the first few percentiles in recogniznig this problem .

Our truck has c. 60K miles on it, including towing a 4,000# trailer for 20K mi or so. I've just quit worrying about this behavior and have nad no problems whatever from the truck. IMHO, Toyotas are durable beyond my ken!