Absolutely the first thing do do ASAP without ANY additional driving to to check transmission fluid level.

If transmission is low on fluid, pump may start to draw in air, line pressure drops, and clutches start to slip.

DO NOT DRIVE if ANY slippage can be detected, as you can very quickly burn up clutch packs and then the transmission is truly dead.

 

Thanks for the advice here. Definitely not driving it right now, luckily I have another vehicle. How will I know if it's "low"? Obviously, if I open the drain plug and nothing comes out it's low, but what if it's a trickle?

 

I second what FJtest said. Check the fluid level. You may at this point want to dump what's in there from the pan since it may already be low and you don't want to run it, risking further damage. Then refill it with about 3.5 quarts of Toyota WS ATF through the fill plug no matter how much comes out when you perform the drain. Plus, that'll let you see the condition of the fluid that comes out, burned, brown, etc. It'll also get you close enough to the proper level to perform an actual level check. This is done with the FJ on level ground, the engine idling, the transmission pan temperature at 115F. You can use an infrared thermometer reading on the pan in a pinch, but from my experience, it will read about 3 or 4 degrees low. Once you reach that temp, remove the level check plug (it has an internal allen hex, not external hex like the drain plug has) and see if any fluid dribbles out. If it does, let it dribble out until it's a trickle and reinstall the plug. If none comes out, shut off the engine and add another half a quart through the fill plug on the side of the trans and recheck.

 

Thanks, I think I'll give this a try. So you're suggesting I just dump the pan, add 3.5 quarts , do the full check, if it's good, reset the CEL and see how it runs?

Do I dump the pan by just opening the drain plug with the external hex and letting it drain till it stops?

 

Yes.

 

It's really simple. If in doubt about the fluid change interval with your transmission, just go ahead and do it. The only real expense is the Toyota WS ATF. Ouch. Other's here have used Valvoline's equivalent, but since we're mixing fluids here and not replacing the entire contents of the transmission (10 to 11 quarts) in one large flush, I just went with Toyota's.

In the spring, I just performed 3 drain and fills since my fluid was OEM and 11 years old. What I did was obtain a 6 quart see-through graduated container from Amazon. I removed the fill plug to vent things and drained out the pan. I did not remove the pan. The filter is just a screen, so why bother mucking with it and resealing the pan? I got around 3.5 quarts on the initial dump, but it may vary slightly depending on what's currently in the transmission. I put back in that amount since I'd never had any leaks and assumed the level was probably close to correct. I then did some driving to circulate the new fluid, going through all the gears of course. This procedure was repeated 2 more times and I took 3 days to do it, letting things cool to room temp each time. On the final drain and fill, I overfilled it slightly by a quarter of a quart from my drain out measurement, about 3.75 quarts. I did that because I'd rather let the excess drain out during the level check procedure than hassle with having to add more fluid working around a hot exhaust system. So when the trans reached 115F ( I was using my Torque Pro OBDII reader with the proper transmission PID's programed in so it could read the trans temp sensors), I pulled the pan check plug and let out a relatively small amount until it was just a dribble, so I was pretty close with my estimate on the overfill. An infrared thermometer can be used in a pinch, but I'd add around 3 degrees to whatever it claims is the pan temp. At least that's what I found when I compared it to what the trans sensors were reporting. The converter sensor will typically read higher than the other sensor once the trans is shifted into gear.

 

Update:

I did as suggested, bought Toyota brand ATF fluid, drained the pain, and added 3.5 quarts using a hand pump with tube to get it up in the fill hole.

Warmed up the engine, waited for it to get up to temp, ran it through the gears manually to get it flowing, and then did the fluid check by draining from the level check plug.

First time I did this, no fluid came out. Uh oh. Might explain my problem though.

So I shut it off, waited for it to cool down, and then added another half quart. Did the full process of the level check again and very little fluid came out this time. Added another half quart.

This time, got a good amount of fluid of of the check, and stopped it when it was at a trickle. Drove the car today and ZERO engine shudder, ZERO tranny slip or hard shifting like I was having previously. Drove exactly like you expect it to, nice and smooth.

Only thing I'm worried about now, is if I might have a transmission leak somewhere. Not sure as I havent done a tranny fluid change in a long time so that could be why as well.

Thanks for all the advice, you guys probably just saved me thousands.