Shaking / hesitation in overdrive

[john123drury]

Hi everyone - 2005 4Runner V6 Auto trans with about 110K. Generally speaking the truck is in amazing shape. However lately I've been experiencing a shake when in overdrive and it's bothering the he** out of me. Sometimes I'll feel it in 3rd and 4th, and sometimes I don't feel anything (even in overdrive).

But the shake I'm describing isn't a shake of the steering wheel. The best way I can describe it is relating it to a manual transmission. You know how sometimes the gears of a manual trans are too low for a slow speed, and the car shakes / hesitates a bit until it's back up to the proper speed for that gear? That's what this symptom feels like.

I'd like to think it's the tires. But then it would happen in the other gears too, right? I've kept up to date with all the regular maintenance (the Gear Oil / Trans oil changes, spark plugs, air filter, coolant, etc.). I thought about the uJoints - but again, wouldn't that happen in ANY gear?

Any suggestions on what could be causing this would be greatly appreciated. Thanks gang!

 

[HokieRunner]

Do a search for 'rumble strip transmission'. Some other folks have had the same problem with overdrive gear.

 

[john123drury]

Thanks Hokie. In reading through the myriad of threads it looks like it's related to either the trans or torque converter. Coincidentally, this issue started happening about a month after I changed the trans oil for the first time. Prior to the fluid change, this issue never occurred (or if it did, my wife never said anything lol).

In the 100,000 miles of driving, it had never been changed. I used the Toyota WS oil, but I only drained 4 quarts of it. I never took out any more. So I'm thinking maybe the mixture of new and old might be causing the problem? I'll be heading to the dealer this week and plan to get another 8 quarts. Will drain another four, drive a bit, and then it one more time. Hoping that might help solve the problem.