I've done a lot of google searching and I see this "rumble strip" issue on newer Tundras but I havent found other 4th gen 4Runner owners with it.

My truck just started doing it this week. It only happens right at about 40mph under light acceleration. At over 45mph its gone. The truck vibrates, it feels exactly like when you are going over rumble strips on the highway. Sort of like when you have a manual transmission car and you are in too low of a gear and are lugging it.

I've got a case of WS transmission fluid on order now to get some good clean fluid in there. Crossing my fingers that will take care of the issue. 75,000 miles on my "100k fluid" whatever. The truck doesnt tow anything and it sees no offroad time.

Anyone else experience this problem?

You're up to date on driveshaft greasing?

I know what your describing may be a bit different. Ford automatics were famous for what you are descibing in the Crown Vics etc. Fresh fluid and some additive minimized the issue IIRC.

I'll be curious if fresh fluid at 75k mi helps you. Good luck!

Yeah I hit those zerks every few months so thats not it.

Also, if I drive the truck in '4' instead of 'D' it never happens.

This is my issue:

The famous rumble strip issue - Toyota Tundra Forums : Tundra Solutions Forum

I too have the No Charge Rumble Strip. - Toyota Tundra Forums : Tundra Solutions Forum

I am going to send some of my fluid into blackstone to see what they can tell me since I've got a kit here handy.

Good read. Lookin forward to the new fluid and Blackstone results

I have a 2005 4x4 V6 with about 90k and seem to have developed the rumble strip issue as well. I am curious if the OP has gotten any traction on getting anything figured out.

It seems like it must be the "Lock Up" feature of the torque converter in 4th and 5th gears. The vibration comes on at the end of 3rd gear when the RPMs are about 2k or so. Then again as it tries to shift up to 5th. In our case as well, putting the trans in '4' instead of 'D' totally eliminates the problem.

I wonder if some sort of reflash could fix things. My current plan is to double check the level on the fluid and be sure the zerks are all lube up.

It is unfortunate that this has come up as we love the car otherwise. If something does need fixing, I am in no hurry to head to the dealership, and I am afraid that a more local type transmission shop will not have much experience with these new super fancy sealed transmissions. I hope that I am wrong.

Sorry to hear you are in the same boat as me.

My WS fluid should be showing up here any day now.

I'll be reporting back when I get the new fluid in and have a day or so to test the truck out.

Based solely on my interwebs research, it appears that the new Tundra guys with this problem who are getting it fixed under warranty are either getting new transmissions or new torque converters. As I mentioned above, it would appear that the TC is the problem, not the transmission.

I am curious if there are more out there with the rumble strip problem on the 4runners. It has been documented in the Tacoma, so it stands to reason that it would be present in these as well...

I've read everything out there Google has to say on this or any related Toyota transmission issues. Since transmission fluid is the only thing in the equation I have control over, I have elected to change it. When I say "transmission issue" I am including torque converter issues as well.

Well, good news. I did my first drain and fill 2 nights ago. (I've bought 12 quarts of new WS ATF so I will do 3 more drain and fills each about a week apart)

So that means I've got about 75% old ATF in there and only 25% new fluid. I wasn't expecting much of a difference until at least my second or third drain and fill but I'm happy to report...

My symptom is now almost completely gone!

The vibration I was noticing during the shift going 40-45 mph is now barely noticeable. Not only that but the shifting in general at all other times is much 'smoother' and less harsh. Although I never thought the truck really shifted harsh to begin with, the sensation during gear changes is now just less noticeable if that makes any sense.

My wife drove the truck and called me at work after, her exact words were "it feels like you put butter in the transmission."

The fluid I drained did not smell burnt and was only slightly darker red than the new stuff I put in. It was just slightly more 'cloudy' than the new stuff, very similar in color though. Oh and buy a decent hand pump... the one I got was junk, it kept binding and came apart twice while I was using it. I need to get a better one for next time.

I will report back in a few weeks once I've done my final drain and fill or with any changes. And before someone asks "why didn't you just flush the system instead of doing drain and fills" ... it's because I didn't want to mess with any hoses if I didn't have to and also because I enjoy my quiet time out in the garage. I grab a few beers, work on the car or truck while my dog watches. I find it strangely relaxing.

Anyway hopefully this helps somebody else.

I am exceedingly happy to hear this. I appreciate you reporting back with your positive experience. With mine, I must say that it seems less pronounced that it did about a fortnight ago. I was just totally convinced that my TC was fragging and sending metal chunks into the lines/valves. I am glad to hear that this seems to have cleared it up for you.

I think there is a case to be made for not doing a flush. Anecdotally, there seems to be cases (mainly with other vehicles, not T4Rs per se) where a flush ended up doing more harm than good.

In any case, I will be performing a drain/refill over the weekend and we will see if it doesn't do the same for me.

Rumble strip issue back today after not being able to duplicate it for nearly 2 whole days.

I was lightly accelerating up hill from 45mph - 50mph tonight and it happened again. As noticeable as ever.

I'm going to continue my drain and fill routine over the next few weeks as once again I currently still have mostly old fluid in the system. Hopefully this was just the 75% old fluid thoroughly mixing with the 25% new stuff.

I also did the 4qt drain and refill over the weekend. For now, the problem is gone! I did not notice a particular increase in smoothness overall, but the rumble strip problem is gone. I will update if it returns. Similar to the OP, the problem went away immediately after changing the fluid and taking it for a test drive.

For the record, I used the Walmart Type VI fluid, which is allegedly compatible with the WS fluids (except Hybrid???).

I am sure there is a clue in here somewhere as to what the real problem is, but so far, I am not smart enough to find it.

Doing another drain and fill tonight.

I have not been able to duplicate the problem again in the past 30 miles of 75% city driving. Smooth smooth.

Crossing my fingers...

Great news for both of you. I know the verdict isn't in yet but it's looking good!

I wonder how much an '03 pan with a dipstick would cost. That'd make this so much easier!

??? That's interesting. In general WS is WS. There were very few choices; now there's more with advent of Dexron VI fluids.

WS is basically the same as TypeVI. It's lighter than Dexron III. It's a little bit like 5w-30 vs a 10w-30. When the fluids are warm there's little difference in viscosity but when they are cool the WS/Dexron VI is thinner.