Transmission drain and fill High mileage

I have a 2002 Tundra with 260,000 miles on it. Truck runs good but it doesn’t seem to be shifting all that smoothly. The fluid on the dipstick is red with no milkyness, doesn’t look burnt or smell burnt. I was thinking about doing a drain and fill but I don’t want to damage the transmission being it has such high mileage. Any ideas if this is a good or bad idea. Bought truck last month

 

Consensus is that doing a drain and fill doesn't hurt the transmission. That's also not saying you will notice it shift any better. Something else that's widely believed: Never do a full transmission flush. Reasons differ but thinking that a power flush may dislodge debris that normally stays hidden away in places where it's doing no harm and putting that crap in circulation can't do any good.

 

I did a drain and fill on mine at 272k miles. Added some lubegaurd platinum as well. Shifts smooooooth.

 

Appreciate the feedback. I was also thinking about doing drain and fill. Running it for a few thousand miles, then draining again, pulling the pan (clean pan), replacing the old filter. And fill again. Any thoughts on that or is that doing to much

 

Run a few thousand miles and drain and fill again? YES.

Drop the pan? Hard NO.

 

When I see threads like this I'm always curious the backstory. How long has the person owned it? Was the transmission ever serviced? Why wait until the transmission isn't working properly to consider service... that kinda stuff.

 

NEVER DROP THE TRANSMISSION PAN ON THESE TRUCKS UNLESS YOU'RE SERVICING THE SOLENOIDS OR VALVE BODY.

Read the first two replies in this thread our community assembled: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

As a new owner, you probably need to go over that info, which our community assembled. It covers this exact question and so many more you don't yet know you need to ask. That thread was borne of people "learning the hard way", and it lives so you don't need to learn the hard way.

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OK, at 100k miles when I bought my Tundra 21 years ago, I dropped the pan and changed the screen out. Useless exercise as there was no filter media, just a metal screen in there. I had some difficulty getting the pan to seal with the included gasket, ended up using RTV. Haven’t opened it since.

 

I want to say that was similar to the experience FGV had also.

And I've seen no less than 3 people on here complain they managed to strip the threads on at least one pan bolt. Stripping one of those bolts, stripping the diff drain/fill plugs, and stripping the belt tensioner seem to be the "big three" commonly stripped fasteners on the 1GT.

 

Guilty. 4 years ago when I was a clueless newbie https://www.tundras.com/threads/transmission-plug-stripped-pan-replacement.105466/

Be careful when torquing the drain plug back onto the pan dont overdo it, you just need the crush washer to crush tightly

 

Something I learned early on working with aluminum engine cases, all you need is a small, sub 6", 1/4" drive socket wrench when bolting oil pans or case covers on. Even then, I'll often torque bolts with only one finger pulling on the wrench. If you're using a full size 3/8" or 1/2" socket wrench, you have a pretty good chance of stripping out some bolt holes. Same thing with drain plugs and spark plugs, the crush washer is doing the sealing and it doesn't take very much force to crush it.

 

Good tip on the small drive. I dropped the pan on my prior 2004 because the drain plug was stripped. All of it was very similar to the thread quoted by DarkMint. I had forgot about scraping off the old FIPG, that was fun

 

Transmission fluid has additives like any oil, but specific to the application. Things like friction modifiers and anti-foaming agents. A drain and fill is always a good idea.

 

This is a myth that's been told since the dawn of time due to its truth with pre-electronic transmissions.

I've repeated it myself, due to the brunt of my experience with pre-electronic transmissions, so no judgment. But it doesn't really apply in the world of electronic transmissions.

 

The theory is that new ATF loosens old crud because it's more detergent and that loose crud does naughty things inside the valve body. The theory makes sense. The screen picks up particles before they go to the valve body, but it only picks up a certain size particle or larger. I have never allowed an automatic go more than 80K miles so I'm no expert on how much abuse they will take. I changed mine the first time at 80K and at the same time, to prevent old loosened crud from being naughty I installed a Magnefine filter with the new Toyota ATF. I think the 20 micron Magnefine will catch anything capable of hindering the spool valve movements in the valve body, but there is always the possibility that crud inside the valve body comes loose and stops a spool valve.
Personally I would take my chances and do the fluid and Magnefine no matter how many miles it has on it.
My 2006 RCLB has about 350K miles on the original transmission, still works like new. I only use OEM Toyota fluid and probably added about 28 quarts over the years. I change the Magnefine filter every 40-50 K miles.

 

Not disagreeing with you here, only adding to the comment.

A lot of theories "make sense", and that's how this crap gains traction.

As @ChattanoogaPhil will attest to, with the condition he had on his truck which he'd considered using an additive to fix (IIRC), and without using anything, it magically corrected itself a short time later ... he'd have been on here preaching that product to the end of time for being the fix. Timing and coincidence are a hell of a thing.

Likewise, everyone has heard the story about the guy who went to the local transmission shop for a full drain-and-fill on their transmission with unknown history. No information on how the drain and fill was done, was no-pressure used, or low-pressure, or was it a high-pressure flush? You never hear that part of the story. Was the vehicle ever used for towing? Who knows, that's never part of the story, because that detail apparently isn't important. Instead, we jump the the fabled result: Transmission dead a short time later. "You took all the clutch particles out of the transmission!!", but we ignore what abuse that tranny saw, what model of tranny it was and whether it had known defects, how they performed the service, whether they used the correct fluid.

All of these stories I've heard much of my life, you're older than I am so you've probably heard them even longer.

• They pre-date electronic transmissions
• They pre-date modern fluids, synthetic fluids, with their targeted modifier packages, synthetic addivite packages
• They pre-date improved fluid exchange methods we have available today

Just like I used to cane the hell out of "Moog is the best steering parts providers on the planet!" 20-25 years ago on the 67-72 Chevy trucks forum - because it was still true then! - in modern times, they're not the same thing anymore, company doesn't function or operate the same, and their parts are horseshit. It's sad to say it, but ... time has killed that one.

Point being: These old urban myth transmission stories need to be killed too. If it was truly that problematic, companies like BG wouldn't offer their own flush service, and you'd have heard a bajillion stories about how it kills 1 in 10 transmissions, but the sad truth is ... it doesn't.

 

There are still lots of transmission shops out there who warn against high mileage first time flushing. If there is any merit to their position at all, I think a Magnefine filter installed at the same time removes most of the risk.

 

There are plenty of steering and tire shops that recommend Moog as having the same rep as 30 years ago also, from the days prior to them outsourcing everything to Mainland China...

I agree on the filter, though I don't and won't put one on my truck. If I started towing, I would be motivated. But Toyota obviously didn't feel it was warranted, they put a loose perforated piece of steel to act as a filter, which shows how little they were concerned about it. In our '06es, at least.

 

I bought a Magnefine filter and transmission hose but they are still sitting in my parts pile. Where did you mount it? I was thinking about zip tying or using a large worm drive hose clamp to mount to the radiator support or the front cross member.

 

I was also thinking about installing the Magnefine filter for a week and then removing it to eliminate this as a possible failure point. I presume this would clean up any larger debris in the ATF as I do successive cold drain and fills.

 

I wonder why we haven't seen a bunch of magic snake oils touting 'suspended clutch material particulates' or "SCMP™️ That Your Tranny Needs!" .


(AI can be fun I guess)

Sad to hear about Moog.

 

I mounted mine on the front crossmember using this kind of "T" bolt hose clamp and a short piece of angle iron with 2 holes drilled in it. The bolt going in to the crossmember is actually a large sheet metal screw because getting a nut inside the cross member is difficult. I figure 20 micron filtration is better than the 50 micron (just guessing) screen. Sorry for the poor photography.

 

The transmission screen is likely closer to 250 micron or larger. 20 is really small.

 

I think 250 micron particles passing through the oil pump repeatedly would shorten it's life.
The disadvantage of the Magnefine filter is the possibility of it becoming completely clogged, restricting flow. If installing on a high mileage transmission, I would replace it at short intervals at first.

 

Some might even say, "it's Magne-fine"

Reverse-logic is a very valid way to look at the situation.

To your point, if suspended clutch particles were integral to longevity and function of modern transmissions, someone, somewhere, would surely be selling it, even if it was being sold as a gimmick repair-in-a-bottle.

The fact it's not widely known, or in a mainstream product, should speak volumes to the invalidity of the claim.

 

If you install one of those filters, just leave in for at least the next 100k miles. It won’t be a failure point unless you somehow installed it incorrectly.

 

Exactly. Had I followed the gas treatment (Cataclean) recommendation from the guy at AutoZone I'd have been 100% convinced it solved the CEL "Code P0420 indicates that the Bank 1 Catalyst System efficiency was below threshold for a predetermined period of time" issue and been a Cataclean believer for life. Instead, I thanked him and decided not to use it. Next day the CEL light disappeared and has not returned. That was end of November 2025.

 

I bought my 2006 Tundra with 201,000 miles. After consultation on this forum, I had a Toyota dealership do a flush. She's run just fine since and she mostly pulls a single or 2-axle trailer. In summer she pulls about 4,000 pounds (the loaded 2 axle trailer) 5 times a month, up the hills of WV.

I plan to have the same done every 30,000 miles.

Hopefully things go well for you, whatever you do.

 

Toyota performed a so-called flush at 100k and 200k on my Tundra. Fixin' to do same now 100k miles later but don't know if it's a "flush" but full fluid exchange with some type of machine at a non-dealer. They did the wife's Lexus at 100k a few weeks ago. Anyway... transmission operates like new as it always has.

After reading about only doing so-called drain/fills I was a bit nervous so I asked the head service guy. He chuckled and said he gets that question all the time. Of the thousands of transmission services they've done he said the only problems were with transmissions already experiencing problems. I believe him.

 

Likely using BG's system. Lots of local shops (use BG's lookup tool on their website to find one) will do this service and replace with BG fluids, which exceed Toyota's OEM fluid specs. It works as follows, hooking up to the lines that pass through the radiator, and uses the natural hydraulics in the engine swap out the fluid while running:

https://www.youtube.com/watch?v=-SC6Uwr9RhI