3rd Gen Automatic Transmission Fluid Level Check DIY

Excellent write up, thanks for sharing.
I asked my local dealer to check the fluid at the first service interval 2 days ago. They refused. Going to have a chat with service manager and ask why (I complained of rough shift going back to first gear and what feels like "hesitation"/varying RPM/under certain acceleration)
If no joy, I'll be doing this myself following your guide.

Mods, this thread should be a sticky.

 

Always wondered why on vehicles with a dipstick why they could not have two marks. One cold and not running and a second one for warm and running.

Thanks for the detailed writeup. Much easier to understand why it is so hard to get a shop to check the level with the temperature range needed. Hard to achieve it after driving to the shop and the shop won't want to wait until it cools off. A dipstick would be so much easier for everyone .

 

Mine is at the dealer now to have it checked.

 

Some (a lot?) do have cold and hot marks. We added a bigger trans cooler to my dads duramax last summer. Checked it when cold against the cold mark line. We then ran it for a while and checked it against the hot/warm mark line. Really nice and easy.

 

I've noticed this too. The shifting in general is pretty harsh but specifically downshifting to 3rd and to 1st, even with the correct fluid level. On varying RPM under acceleration, I think this torque converter locks up and unlocks at certain speeds. I've noticed when slowing almost to a stop then accelerating, the truck will stay in second gear and will have a sound and sensation very similar to feathering a clutch when I start accelerating again. I think this is the torque converter initially unlocked, then locking up. I do not know for sure - this is purely speculation on my part.

 

My 2018 has the harsh 2nd to 1st downshift, but I haven't checked the fluid level yet. Per my dealer its a software thing and not a low fluid issue though. I think you are right it could be the torque converter locking and unlocking. I have learned how to stop to keep it to a minimum though. Just another little quirk ha

 

Thanks, I've been working on this same project and you have written up a good easy to follow procedure.

 

https://www.youtube.com/watch?v=maK7HsGEEls

https://www.ebay.com/itm/Toyota-Lex...345970&hash=item33dbdb8b0a:g:AFkAAOSw8b1aGFbV

https://www.ebay.com/itm/SCANGAUGE-...941651&hash=item3a5e9ec66f:g:07IAAOSw~gRVpckM

I'd much rather just use the above method in the youtube video. Seems much easier than sticking paperclips into your electrical system. I'd also install this (Toyota & Lexus Sealed Transmission Fluid Replacement Kit) from eBay. Makes the fluid change much more streamlined.

 

That's actually a good idea. I feel like you could probably purchase everything for less than $75. I didn't see anything about the transmission temp reader. I'll have to see if I can find one of those.

edit*

$160 ScanGauge SGIIFFP Ultra Compact 3-in-1 Automotive Computer with Customizable Real-Time Fuel Economy Digital Gauges (Frustration Free) , Black

https://www.amazon.com/ScanGauge-SGIIFFP-Automotive-Customizable-Frustration/dp/B00VX2NOK2

 

It's actually a scan gaugeII reader. It would come in handy even if you weren't doing this maintenance.

https://www.ebay.com/itm/SCANGAUGE-...941651&hash=item3a5e9ec66f:g:07IAAOSw~gRVpckM

 

Thanks & subbed

 

Thanks, I had just realized what it was and edited my post lol. I guess I need to get one for this truck.

 

No shifting issues if you OVtune. SO much smoother

 

Great write up. Thank you.

 

Just checked my '18 today using the method rowsdower put together in post #1....Went well. Took 2 hrs but then I went slow to get it right.
Added 1 qt WS fluid..... drained back out 900 ml so transmission was pretty close to full....
Thanks rowsdower for the detailed writeup! Was worth the "peace of mind " effort imho.........
.......Oh ya I should add for those who are going to do the test as described in post 1...... the time from cold start (ambient was 74f) to the "D" showing (95f) was 12 minutes and the time until the "D" started to blink (113f) was 9 minutes..... So I had 9 minutes to do the overflow draining...... Actually took less than 2 minutes.....

 

Something to add to this post, if yout truck has 30K miles or so already, it wouldnt hurt to fully drain the pan. Then replace that much fluid plus the extra quart before starting this how-to. That would get you some fresh fluid in there, and doing dump and fills every 30K is (imo) better and safer than doing a flush at 75K.

 

I might do this

 

Wouldn't hurt. You can be sure it wasn't done pre-delivery

 

your fill plug pic does not look like mine on my 2018.....hmmmm

 

Do you have a 4x4?