UPDATE
The vibration was caused by the front driveshaft u-joints binding. Had the front driveshaft u-joints replaced and the vibration is gone.

ORIGINAL POST

Today when driving my 4Runner (cold) I hit around 25mph and the rumble strip feeling appeared. It got worse up until around 35mph then started to disappear, however it did not go away completely.

After doing some reading on the forum, I came across the rumble strip threads. 4Runner is a 2003 Limited V8 with 173,200 miles on it.

1st drive
After some test driving I could get it to disappear when putting it in 4 or 3. So I thought okay rumble strip issue. Letting off the gas would cause the issue to go away and so would putting the tranny in neutral.

2nd drive
Had to drive back from work and sure enough the issue was still there. However this time it was present in D, 4, and 3. Same exact feeling as before, and it would go away if the tranny was in neutral or if I let off the gas. The issue would appear around 25mph and act as before, then be almost no existent around 50mph then come back between 60-65mph. Didn't want to go any faster than that.

I also tried accelerating quickly from 40mph and my 4Runner didn't seem too happy. It seemed like it didn't have as much power (engine revved up fine, seemed like it was producing all its power, but felt like it wasn't going anywhere) and sounded off.

End of 2nd drive: Go to pick up a friend so he can experience the issue and its completely gone. Still seems like I might be missing some power though. I'm just waiting for it to come back. Transmission shifts completely normal.

Is this still the rumble strip issue? After reading the forums it seemed the general consensus was that if it was the rumble strip issue, it would disappear in 4 or 3. Mine would at first, and now its present in D, 4, and 3. Then finally gone, for now at least. Also what fixes did people go with? I saw a variety of things from torque converter replacement, tranny fluid exchange or flush, to "Shudder Fixx" from O'Reilly.

Just because it'll be easy to do remove your heat shield below feet , cpl run underneath ! Specially on older model .

tranny flush fixed mines, i had the same rumble at slow acceleration with drain and fill. got it flushed at the dealer and so far so good.

What is the service history on your transmission? I'd start with replacing the fluid before adding any snake oil.

We haven't touched the transmission since we bought it used in 2006. Yesterday I scheduled an appointment to bring it in and get looked at, but with the issue being gone not sure what to expect.

Took it for a short drive today. Issue is still gone. Not sure what to think or do.

i did the fluid exchange and added shudderfixx. took 500 miles to release, but its gone now.

I'm glad I found this post. I've been having some vibration when accelerating around 20-35 mph for over a month now. It's not as bad when it's cold outside, sometimes doesn't happen at all. When I exceed 40mph, it goes away and drives fine. No vibration when braking. I'm at a loss. I've taken it to 3 shops. They ran a misfire test and all was fine. One shop said my tires were out of balance. That still didn't fix it. I'm thinking maybe now I need the transmission flushed? Your thoughts? Thanks!!

exact thing i did and solved my issue but it took less than one mile solve my rumble issue.

I drove my 4Runner again today and no shudder, that is until I came off a hill and made a right hand turn. Heard some clicking/metal clacking noises from underneath then the shudder began. Heard a few more noises then the shudder stopped. I went around a round about immediately after and the turning did not cause the shudder to come back. The rumble never came back for the remainder of the drive. Taking it in to get looked at tomorrow.

What you have us different than rumble strip. Rumble strip is the torque convertor shuddering on lockup. It is only felt and not heard. My 2007 4runet would only do it in d. If I put it in 4th no problem.

Just got back from bringing it in. The shop said I have a nail in my right rear tire and that the low pressure could be causing the shudder cause of binding with the AWD system. They also said that I have some play in the rear driveshaft and the u-joints might need replacing. I'm at college now and they said I should be good to drive home and have the driveshaft looked at at the shop I go to at home. Nail in the tire will be fixed ASAP however.

my rumble came back. its the tires. probably was the whole time. felt exactly as everyone here describes.

getting new ones put on next week. here's hoping...

As I read this thread and before I got to this part ...I said to myself it's your driveshaft not your tranny. Here was mine just a couple days 2003 @285k

It's very unlikely tires you would have to notice that much of a low pressure on a tire for them to cause any of the descriptions in this thread ...I mean I can air down my tires to 18psi and do 70-80mph on the highway and not feel jack s**t
Tires..lol