DIY: Full Flush for Automatic Transmission

This stuff....

 

The loose fitting filter doesnt sound correct.

Just to check, you are doing the fluid level check procedure with the engine running?

 

Sounds like you've done things properly and used the correct fluid. The filter issue sounds odd. If you still have the old filter, you could likely just clean it up, it's just a screen really. How did the old fluid look?

 

You used OEM fluid but what filter did you use? I got one off the shelf at NAPA. I wanted to get a Toyota OEM filter but never got around to it. My truck has been running great. I would drain the pan, save the fluid, replace the filter, seal the pan, add the fluid and get that truck up to temp while jumping the 4 and 13 OBD to know you're at the correct operating temp.

 

The fluid check was done with the truck running and with the AT temp check light illuminated on the dash. The old fluid was slightly darker, but didn't smell burnt and wasn't bad looking. I don't have the old filter anymore, but I've got another replacement on order. I think I'll be replacing it again and trying to save what I can from the new fluid. I'll let you guys know what happens over the weekend once I get a chance to work on it again.

 

@agent4573 Also, the ATF temp range was changed from 115-130F to 97-115F. Fortec’s thread has not updated to the new temp range even though some members have asked the powers that be to update it. The lower temp range adds more ATF in the transmission.

 

Like @nikkerton asked, what brand filter did you install and is the new replacement on order the same brand as well?

 

The 1st replacement filter was not OEM. I assumed since it was such a simple part that any brand would do. The new replacement is a WIX branded filter from rockauto.

 

I've got an '08 and my tranny was well over a quart low - thinking from when they added the cooler.... never slipped, but shifts were very hard and jerky, but never slipped out of gear.

 

Issue solved. The replacement WIX filter came in today and I got it swapped in. It looks like the Amazon one had the right diameter, but the wrong thickness oring installed. The filter was bought from a reputable store on Amazon, but with the bin mixing Amazon does, I should have known that I would end up with a cheap knockoff anyway. Lesson learned.

The new filter went in with a little bit of resistance on the oring (as expected). I saved all the fluid that came out when I dropped the pan (minus about 1/4 qt that spilled) and it ended up taking all that plus another 2 quarts to fill the trans back up to the right level. I then put just a touch more in as I've seen posted elsewhere. Another upside to the WIX kit is they purposely make the bolt holes in the gasket smaller than required. This lets you put all of the pan bolts through the pan and capture them in the gasket before you put the pan on the truck. No need to go fishing around and trying to line up the rubber, it was completely held in place on the bench.

 

Good work! Yea I didn't touch the pan / filter but may have to next time if I still have the truck

 

That’s great news. It’s wild that a seemingly insignificant O ring can have such an impact on proper operation!

 

Sealing is important! The infamous Challenger disaster was caused by faulty o-rings. They seem like simple parts, but they are actually incredibly dynamic parts that provide very important roles for many applications.

 

Yes, the O Ring could have been the culprit, but not sure why it took 2 more quarts the second time. More likely those 2 quarts low were chiming in also.

 

My guess is that it got to a certain level of full, then it started sucking air past the oring. Since the level check was done at idle, it reached a balance of pumping a mixture of fluid and air through all the internals, and I'm betting that mixture had about 2 quarts of air in it. Once the oring leak was fixed, it could flush those 2 quarts of air out and needed the extra fluid to replace it. It was driving like it was low on fluid, but the level checks kept coming back full, so there was definitely air trapped somewhere taking up the extra space.

 

Anyone here follow The Car Care Nut on YouTube? He is a Toyota mechanic and seems to be very knowledgeable. I did the full flush on my transmission as described in this thread at 100,000km (60,000 miles).

I watched this video tonight (between 4:05 and 9:36 for his talk on the transmission fluid):
https://youtu.be/TevK-u3vkx4

He recommends not fully flushing the fluid, with his reasons fully explained in the video. His recommendation is to do a drain and fill every 60,000 miles. The earliest he recommends to do a drain and fill is 30,000 miles.

Made me question my logic and what I'm going to do going forward...

 

@Audi403 I’ve seen his videos but I don't follow him. He hasn't said anything about general vehicle maintenance that hasn't already been covered by other mechanics.

 

Hello, I'm new here and read this entire thread. I didn't search for newer threads. I have a 2021 Tacoma TRD 4x4 with V-6 engine. The On my 2021, the auto temp light is not available or shown in instrument cluster. You follow the this exact same procedure but shift from Drive to Neutral and watch for the D to blink. While in neutral or Drive (whichever you end up in after the shift procedure) the D or P (park) will not appear regardless of your shift position. That's how you know you're in the transmission temp mode. When D reappears, that's how you know you're ready to check transmission fluid level. I did it this weekend, and it worked great. You still jump the same wires. Mine was a full 1/2 quart low from factory. I checked. I ran the procedure a few times so that I was comfortable with the temp/check procedure. It worked great. So, I thank the OP here for the info. After getting my transmission up to temp (it took about 10 min), I was ready to check and the factory fill was quite low. Before I started, I added about 1/2 quart and did the procedure. After only 11k on my truck, the color in the fluid was noticeable. However, I realize the color is not a determine factor. Just thought I'd add to this great thread. Thank you!

 

garden spayer 3 quarts at a time threw the cooler lines for the win

 

Does it have to be the listed brands of ATF ? Could I use Valvoline full synthetic?