[katekebo]

It's well known problem with this generation of RAVs. It is caused by faulty (porous) transmission case casting. The only remedy is to replace the entire transmission. My wife's RAV (2016) had it done at 42k miles. The dealer replaced the transfer case TWICE, but it was still leaking. Then they replaced the transmission and the leak went away. $8k in total, covered under warranty.

Watch the video below. The transmission oil leak problem description starts at ~2:00 min. Although the video mentions 2014 and 2015 models, my wife's was 2016 and still had the problem. From what the dealer told me, basically all 4th gen RAVs are plagued by this issue. The service advisor I worked with was aware of at least a dozen of cases he had personally had to deal with. In some cases the leak was apparent from new, in other the leak didn't start until well after the warranty expired. Bottom line, Toyota never got the transmission case casting right through the entire generation. Toyota would cover the repairs under the 5yr/60k miles powertrain warranty, but through a tortuous process. The instructions to the dealer were:

1) First try to fix the problem by decoupling the transfer case (actually transfer case extension) from the transmission and reseal it.
2) If this doesn't fix the problem, replace the transfer case (as it is much cheaper than the transmission).
3) If the transfer case replacement doesn't solve the leak, replace the transmission AND the transfer case.

My wife's car had to go to the shop 4 times, because the first replacement of the transfer case appeared to solve the issue, only to come back two years later.

If your car is out of warranty, you're out of luck. Toyota never acknowledged the issue publicly, so they won't give any warranty extension or "goodwill" adjustment for the repairs. The "case manager" at Toyota played stupid ("never heard of the issue"), in spite of ample evidence to the contrary (as per the testimony of the service advisor).

 

[katekebo]

I’ve had good success using At-205 Re-Seal available on Amazon. It sealed up a twenty year old John Deere I have

DON'T use this stuff in a modern car. This may be good for a tractor, but modern cars are build to much tighter tolerance and you will end up clogging a lot of the tiny, narrow passages the oil has to flow through. You will end up causing more damage.