ATF Full Flush OR Drain N' Fill (w/ Brown Fluid & Slipping Trans.)

I have spent the better half of my Sunday researching this topic and am feeling pretty conflicted.

I bought my truck with 42k miles on it and do not know the service history prior to purchase.

I had an ATF drain n’ fill done by a local shop at 68k miles. The truck just hit 80k miles. The ATF is currently brown and I’m pretty sure my transmission is slipping – I’ve noticed pretty delayed acceleration when I floor it and it doesn’t engage into reverse right away.

I am trying to decide if I should have a full flush done OR just do a DIY drain, pan drop, new filter/gasket, then refill.

I’ve read that a full flush is fine as long as the fluid isn’t black/burnt, which makes me want to go for the full flush BUT then I also just read that if your transmission is already slipping you may want to avoid a full flush?

Any suggestions would be so greatly appreciated! Thank you!

 

You can drop the pan and see if the transmission filter is "busy" with particles and if they are change the filter and change the oil using the ole drain and fill technique.
Some the causes of the transmission slipping are.

1. Clogged transmission filter, Not likely but possible.

2. Leaking piston seals within the transmission.

3. Excessive transmission pump wear.

 

doesn't hurt to try a pan drop, filter change, refill (usually around 6-7 quarts for this) and see if anything changes

the fact you've done a drain/fill and now at 82k you have brown means you use your trans more than most and need to keep a shorter maintenance cycle or add an additional cooler

if it still slips then you may need a rebuild or low mileage replace :/

 

Thanks for the quick responses! A mechanic was the one who told me my ATF was brown, but I just checked the dip stick myself (at operating temp.) and it definitely doesn't seem that dirty to me - I'd say reddish/pinkish with maybe a little brown and it smells sweet. Also, I am not really 100% sure my transmission is slipping...maybe I just feel like acceleration is slow because it's a smaller (2.7L) engine and I have a heavy camper on the back.

Does anyone have any tips to definitely know if my transmission is slipping?

 

Usually slipping is feel, you'll notice it rev up while in drive, but no acceleration from the truck.

A quick spill and fill was a good idea, leave it in there for a bit, my next step would be a pan drop. You get more fluid out and you can see the true state of the fluid.

 

Thanks for all the advice! I'm going to do some drain and fills every couple thousand miles. Two questions on that - should I drop the pan/replace the filter before OR after doing multiple drain and fills? Also, my dip stick say Dexron II....is it ok to use

$25 Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid 1 GA

Valvoline MaxLife? (2001 2.7L 4WD 4 speed automatic (3RZFE Engine)). Thank you so much!

 

I dont like high mileage fluids, ive been in automatic for 15 years now and the high mileage fluids are good for sealing small leaks yes and may have a few extra additives BUT they do swell the old seals and continue to do so. If you use it I wouldn't run it Long term. Just my past experiences with them and having seen my customers have similar issues. I was raised to use high mileage oils and changed that as I learned.

 

read this https://www.tacomaworld.com/threads...p-your-4-speed-automatic.325531/#post-8538150 @gearcruncher is the AT guru.
i did 2 D&F's then cleaned the filter screen, then did a 3rd D&F. i used maxlife ATF.

 

Have you been running with overdrive in the "on" position? That camper shown in your avatar looks pretty heavy. If you've been leaving the OD engage, you may have damaged the trans.

Also, do you use the ECT button? Again, with that camper on there, that would likely be beneficial.

 

Thanks for this input! What would you suggest I use long term instead of a high mileage ATF?

 

I never turn O/D on, so that shouldn't be causing any issues. So you're saying I should try driving with ECT on due to the heavy load? I've never touched the ECT button either...always leave it off.

The camper is light as far as campers go (Hiatus pop-up camper), but a lot heavier than an empty bed! that is for sure.

 

yep, turn ECT on. it holds the gear a little longer and engages a littler sooner when shifting down

I turned mine on years ago and that's just every day normal driving

 

Ok this is embarrassing, but I just realized that pushing the O/D button turns O/D off....so I guess I have been driving with O/D on the whole time. Sounds like that is especially bad when driving over a mountain pass with my camper....but do you think I should turn O/D off even when I'm just driving around town?

 

2002 here... Original owner. ECT is always on and OD is always on. 160+k and never had an issue. (Knock on wood lol)

 

when the dash light comes "on" it says O/D off so by pushing the button every time you get in (which I do) you turn O/D off anyway. I also downshift into 2nd when slowing down and leave it there when driving under 25.

All this is every day normal driving around