V6 Transmission Fluid - Drain and Fill or Flush?

For what it’s worth, I’d use a transmission shop that has solid reviews over a dealership. I asked my local dealer about the transmission service cost on my truck and was told “those are sealed transmissions and we don’t service them.” That was all I needed to hear. The drain and fill procedure seems a bit overwhelming, but it is honestly quite simple.

 

Learned something new today...

 

I thought it was a screen too at first.

 

If you are in New England you are welcome to come by and I’ll help you do it. Easy peasy. I second the no flush thing. Why introduce contaminated fluid back in. They use the machine to remove and replace. I prefer to mitigate risk. I also agree with skipping the pan drop and filter clean or replace.

 

Experienced transmission shop says they'll do a full drop of the transmission and do a drain and fill for $250.

Local shop that I trust with general stuff says they'll do a drain and fill (without dropping) for $175. I had them explain the procedure and they said they'd drain it, fill it back with the amount if fluid drained out, and check the level of fluid with the engine warned up and overflow valve activated.

 

Can someone explain what a “full drop” is?

 

Sounds like they'd remove the bottom pan or something from the transmission to get all of the fluid out. Apparently, only around 2/3 of the fluid can be changed with the typical drain and fill method.

 

That's because oil is in the torque converter, passages, hoses, cooler etc.

 

Last question: shop is letting me purchase and bring in my own fluid. How much fluid should I bring?

 

Please watch this video if you want to understand what a "full drop" or full transmission flush is. 28 minutes at 1x speed that is WELL worth your time if you want to understand changing the fluid in your Taco (even if you don't do it yourself - understanding the steps will help you be a more informed consumer).

 

So, a full drop means a full transmission flush? I’ve seen other videos that speak to this process. I agree with the process. Just didn’t know it could also be called a full drop. Still suspicious though. Thanks for your time and help.

 

I do find it funny how he, at time stamp 7:25, shows how great he is a gauging 18 ft-lbs. If he over-torqued it to 20 or more ft-lbs the result would be the same. The torque wrench would simply show no more torquing required. It wouldn’t necessarily mean it IS NOT overtorqued.

 

No flush machine.
IMO, there's one of two ways to approach it.
Drain and refill every 30,000 or full fluid replacement every 60,000.
Full fluid replacement is basically three drain and refills, with a cycling procedure between each. IMO, 3 drain and refills does an acceptable job of getting most of the old, out.

If the dealer is replacing all the fluid, they are more than likely using a machine. Draining and refilling three times would obviously take more time...

That said, you'll want about 13 quarts for a machine flush and 12 for 3 drain and refills.

 

Depends if you are doing a full flush or just a fill. Bring however much you want if you just want them to drain the pan and then refill back up to the proper levels. Two quarts will probably come out of the pan. They will need to measure how much comes out, put the new amount in, bring the trans up to temp then check the levels. From there they may need to fill more if your trans was low from the factory to begin with. Rinse and repeat.

• Page 543 of your owner's manual has the information you need re: fluids (I linked the 2021 Taco manual)

 

first off these truck have ws which is good to 100k, it’s advertised as “for the life of the vehicle” but I don’t trust that.

I hit a deer and my cooler developed a crack and spewed all over the side of my truck, I have 80k mostly highway and the fluid was still redish but fading so 100k imo is yhe max.

again WS…I plan to use amsoil but you must pay attention as ws has a much lower viscosity than t-iv.

typically when people talk about a shop flushing it’s using a pressurized machine, these have damaged many transmissions.

what the video posted shows you is filling the pan and only letting what you added to flow out, should work on 3rd gen but you should note that is not a 3rd gen so you’ll be filling at the transmission as we don’t have a dipstick…but the procedure is the same; my cooler (‘17 trd offroad 4x4) is separate from the radiator and mounted in front if it up high right behind the grill. be cool if there was a line that pulled fluid but I don’t think there is one; they all just push fluid out

you can also do a drain and fill, run through the gears, drain and fill again, and repeat…but the method shown in the video is probably the fastest way and only way to not mix old/new fluid.

again for a 3rd gen either yota ws or amsoil signature series fuel efficient, their oe fuel efficient (which pops up when you put in year/make/model) is NOT ws compatible with ws but t-iv…so be careful.