Thoughts on transmission flushes?

18ft KZ here

 

The most important thing is that we have transmission oil coolers, do you also have a thermometer attached to yours?

 

I dont think so...
Do I need one?

 

I have an ultragauge set up for torque converter and pan temps. It’s quite an eye opener. Definitely worth the money. It’s amazing how much heat she generates unlocked and with lots of throttle, such as climbing a steep gravel road in 4hi or towing a trailer up a long pass.

 

But I mean...what exactly will I do about it? I do I really want to see those numbers? I already drain and fill the tranny every 10k lol

 

Based on the builds you've done, your attention to detail, knowledge of technical data and particulars for what the MFG calls for, imma Listen real closely to you habits. REAL closely

 

I mean I guess you could extend the intervals a huge amount. Watching temps modifies your driving style a bit and you’d be surprised how cool it stays under normal use, and sometimes even heavy use.

when you see temps skyrocketing you can back off. The fluid lasts a million miles if it’s always cool.

 

Kind of a tight fit for a transmission...

 

I fix transmissions for a living and have probably flushed well over 5000 vehicles .
Do I flush transmissions ? Yes , but I flush by following the proper procedure .
I do not take chances like some quick lube shops do by leaving the pan on .
Those lube shops send their mistakes to me . How do you possibly know whats laying inside the pan ?
Whats a proper flush ? Removing the transmission pan and inspecting the magnets and filter for debris first .
If the magnets were full of metal , I do not flush. If the filter was full of brass and plastic , I do not flush .
If the pan magnets and filter are squeaky clean , I will flush the remaining fluid out of the cooling system and converter .

Because this is a 3rd gen post , we can go into a little more detail regarding The AC60 series transmission .
The valve body in this transmission is made completely out of aluminum . When fine particles get past the filter , the particles manage their way into the valving and work like sand paper on your aluminum valves which over time, greatly reduces the life of your transmission . The truck continues to shift and the operator believes everything is fine . What he doesnt know is 1/4 of his fluid pressure is now cross leaking into another hydraulic circuit . Because this is a computer controlled transmission , your computer adjusts for this leak and you think everything is working good

What can we do about a cross leaking valve body ? Prevention
Keep your fluid fresh and clean as possible
I believe Toyota says to change the fluid every 60K .
Thats only a guideline gentleman . The boys who make the Aisn Seiki AC60 Series transmission say the fluid should be changed every 30K
Are you in stop and go traffic every day ? 4 wheeling on a constant basis ? Towing?
Toyota,s WS fluid breaks down just as quickly as any other fluid .
You can prevent some of this by monitoring your transmission temps .
https://www.tacomaworld.com/threads/transmission-coolers.526283/

https://www.tacomaworld.com/threads/3rd-gen-transmission-cooler-upgrade.482280/#post-14723804

 

I 've done 4 complete flush and fills on Gen 3's - mine and three local TW members - takes about 1.5 hours to do including fluid level check. I did mine at 40K miles - towing in summer months - and had no Scangage or other equal to monitor pan and converter temps. My fluid had a hint of cherry red left in it. I purchased a SC II and added an additional cooler to the tow package cooler. The others had about 60K miles and were general usage and some 4x4 - all had tow package and monitored temps - the average use running temps were 180+ and sometimes above 200. The fluid that came out was coffee brown - completely shot. GL with your decision(s).

 

The gauge is useful for monitoring for issues if you are really loaded down and pulling fast or on steep grades, or 4-wheeling in remote places. If you are on flats mostly and are only pulling say less than 3,000 lbs, keep good tally on your fluid levels, and stay where help is easy to get, I wouldn’t worry about it too much. In my case, we trailer over mountains and offroad a lot, often too far to walk out safely in the summer, so I like knowing those temps!

 

Toyota had a policy of no touch, no flush on the FJ cruiser AT.

Well that caused failure in a large qnty of vehicles.

In many cases, a flush at first sign was able to fix the issues, others got to replace the transmission at 75k miles.

To date, it's the only real problem that vehicle had that buyers need to be keenly aware of.

I guess what I'm saying is that Toyota's definition of "life of the vehicle" may be different than yours.

 

For a Toyota transmission, I flush at 60k. If I get one with 100k+, I only do a dump and refill but not a powered flush like the dealer does.

 

I dont think the dealer has the ability to power flush a transmission . Its actually impossible unless somehow they flush with someone sitting in the truck with their foot hammered down on the gas pedal . If they use the term power flush , its a term used to get you in the door. To be honest , its the last place I would bring my truck for any transmission work unless warranty

The dealer uses a flushing machine that uses your transmission pump . Your engine is at idle and fluid pressure circulating through the transmission is approx 15 psi .
If you are at the dealer for a flush , chances are , the re-agents in your fluid have broken down .Your original fluid worked hard keeping your transmission cooled, lubricated and clean by depositing tiny particles on the bottom of the pan and magnets .
When you introduce new fluid with a very high detergent rating into a transmission with old fluid , the new fluid can lift particles off the pan and magnets and work those particles into the valve body .

 

So doing frequent drain and fills is potentially harmful? What if you drop the pan, clean, and replace filter each time?

 

Relax more it’ll go

 

Dropping the pan is priority for every transmission service
If you are frequent with your drain and fills , there are less chances of sediment lift

 

Over the years i’ve learned the hard way never to put any additives or ‘flushing’ products in any of my automatic transmissions (other than what’s recommended)
But just dropping the pan to change the fluid and filter will always leave quite a few litres/quarts of old, dirty fluid in the torque converter, cooler, lines, passage-ways, etc. If I was changing my fluid every 10k miles it wouldn’t be a big deal, but since the intervals are so long, I really want to make sure I change all of the old fluid.
Using a DIY pump or a proper machine to do a complete fluid exchange (not a flush) and then dropping the pan to change the filter is really the best way to do it IMO........(*and yes, I realize this wastes some new fluid)

 

What's the procedure for this? Drain, drop and clean pan, reinstall pan (and new gasket?), then refill with fluid?