Transmission- sounds like rumble strips

2010 4Runner - 215k miles. Two weeks ago the vehicle occasionally made a sound like running over the rumble strips on the interstate. Quick research uncovered the torque converter wasn’t happy with the old fluid. Drove it in manual mode until I could get it to the shop to minimize the torque converter dependency. I believe the fluid is promoted as life-time fluid but transmission isn’t happy. Some said to do nothing but that didn’t make sense to me… as the trans was calling for help. Took it to the local tier 2 Toyota shop. Had them drop the pan, change trans filter, gasket, and put 4 quarts of Toyota branded trans fluid back in. Also added friction modifier / shutter fix to the new fluid. So far… all is good. The trans holds 8 quarts of fluid but only 4 in the pan and the pan is hard to fill. I will take it back in 2-3 months and change the fluid again which means about 75% of the fluid will then be new.

 

OK

 

"added friction modifier / shutter fix to the new fluid" - it's a new one. does it makes original fluid better?

 

The word lifetime in lifetime fluid is not defined anywhere that I know. Probably on purpose, because then they can always say the fluid lasts the lifetime of the transmission. Which is your case is 215k miles.

Good to know that product seemed to fix things. That might be the best solution when its never had a change after so many miles.

 

I do know that most folks believe that Toyota’s ATF WS fluid is a very good product. I don’t know the chemistry w/in the friction modifier but I had read that 2 or 3 other folks with the same 4Ruuner issue had good outcomes using it so I elected to use it too. It was also recommended as ann oil additive to the posi rear differential I installed on my 1970 Mustang so somehow it makes gears work better together.

 

It is a lifetime fluid.

It lasts the lifetime of the fluid.

 

LOL - you added trans fluid to the rear of your '70 Mustang? I'm thinking you're a troll with this post and your other one about the eatery weatherstripping.

 

At that mileage, it might be a good idea to check your u-joints while you're at it.

 

No, friction modifier. I read the same things about the rear diff (limited slip) on my '04 JGC. The positrack and limited slip diffs don't like to slip very well in tight turns (I used to have scrubbing sounds circling tight parking garages that no mechanic could diagnose).

If you add friction modifier it helps them slip a bit easier - but that kinda goes against the mechanics of it all in the first place.

I just let mine grind and it was still fine after 215k miles. But there were regular fluid changes on it - not a lifetime fluid