How does the 5speed transmission get overfilled?

Just a straightforward question I guess. I checked my transmission fluid the other day after getting it serviced and when I took the fill plug off (not the drain plug, trust me), about 1/4 quart of fluid poured out of it.

My understanding is that the transmission takes 2.6 quarts of gear oil according to the owner's manual (I'll double check that number later when I can get to the manual), which is the equivalent of filling it up until the gear oil starts to drip out of the fill port.

So how does an extra 1/3 quart of fluid end up coming out of the fill port if it was filled up to that point?

FWIW I checked it when it was cool, not operating temp. I decided to check it because my transmission was feeling more notchy than usual after being serviced. I was more expecting it to be under-filled and was a little surprised at it being the other way around.

 

Filled on uneven ground.

 

That reminds me, I should mention that I checked it on even ground lol.

Seems odd that Toyota would fill it on an uneven surface (or unevenly lifted) but I guess that's one likely explanation. Just wanted to be sure I wasn't missing something because with that much extra fluid it makes you wonder if it was intentional or not.

 

Did you check the transfer case oil level. If the seal between t-case and Trans were bad could dump gear oil into trans.

 

I have not, I'll do that...thanks for the suggestion. Wouldn't it be likely to be leaking on the outside too if the seal was compromised that badly?

I'll check it tomorrow when it's light out since its easy enough to do just to rule it out if nothing else

 

Its easy to to do if you using a pumper and stuff the end of the line into the fill hole and quickly put in the plug when its full.

 

Just where did you have it done ??

Most places the mechanic wanna bees get tasked with doing the service work

Air operated gear oil pump if the gun end was set to high the tech just pumped the gear oil in to it quit .

Quite easy to get extra in and not allow it to all drain out .

 

Yeah its real easy to get extra oil in there, certainly nothing to worry about....

 

The dealer will remove the shifter and fill through there. IIRC it's recommended to run 1/4 to 1/3 quart over to help with smoother shifting.

 

Had it done at Toyota. Normally I would do it myself as it's an easy enough DIY thing to do, but I was getting other service done and figured I'd have them do that since they were under there anyway.

huh, interesting. I didn't know that was even possible lol.

 

Why would they take the time to remove the shifter to put gear oil in??

Unless they bill a hour labor to fill your gear oil and a hour to drain it ??

Maybe it is the fill it to the top and call it good.