Transmission fluid change out question

Just bought a 2007 Prerunner, DC, 4.0, auto, from the original owner.

It has 247k mainly highway miles.

As with any used vehicle, I'm setting a maintenance baseline by servicing all fluids, filters, plugs and general maintenance items.

Previous owner indicated the transmission fluid has never been serviced.

I called the local dealer parts dept for other stuff and after a short conversation outlining what I'm doing, he said that if the transmission is shifting ok, to not service the transmission fluid. That it could cause problems since the tranny is used to the thicker older fluid.

Is that a thing?

Advice please.

 

The old thicker transmission fluid (i.e., sludge), is full of grit. Thus (in theory) provides better “traction” between transmission components.

The shop doesn’t want to touch it because if they do change the fluid and a issue occurs the customer will blame the shop.

IMHO chance the fluid, a drain and fill is a easy DIY. If new fluid cause problems then the transmission was on its way out (anyway).

 

I have an old Isuzu that was mistreated and not serviced properly by previous owners and had a small leak I couldn’t get to stop staining my driveway unless I removed the trans pan. I had heard of what the shop explained to you, but decided I wasn’t going to try saving and reusing the old dirty fluid that looked like burnt engine oil, so filled it with with new……………… a few weeks later I was dropping and replacing the transmission due to it slipping really bad and then breaking down completely. I’m sure you’ll find people that have done it and didn’t have any problems, but figured I would share my experience.

 

If it ain't broke don't try to fix it. That transmission will give you at least 400,000 miles as is as long as you never let it overheat. My Tacoma has 218,000 miles on the original fluid and I have no plans to change it until I have the transmission rebuilt or replaced. Guys that insist on changing their fluid every 30-50K will literally spend more on servicing their transmissions than it will cost to repair them when they wear out. And there is no evidence that changing the fluid will extend the life of a transmission. That is an old school idea that MAY have been true 40-50 years ago.

Transmission fluid doesn't serve the same purpose as engine oil. As long as it never overheats it doesn't go bad. If you ever let the transmission get too hot it is already fried and changing the fluid won't help. If the transmission is still in good working condition changing the fluid won't hurt a thing, won't help a thing either. But if the transmission has been damaged keeping the old fluid in there will buy you some time. It may still continue working just fine for another year or 2 depending on how much you drive. But if it is damaged and you change the fluid it they usually die within a few hundred miles.

At this point changing it will gain you nothing, and might cost you a lot.

 

FWIW. I did a fluid/filter change on mine. Not a hard task. Fluid + filter w/gasket was about $75. Time was about 90 minutes. I had to run thru the Temp Check mode engage sequence a couple times before the system engaged.

Prior to the service, the tranny was a bit slow on shifting and sometimes the shift was hard/abrupt. Afterwards, the shifting was so smooth I had to look at the tachometer to notice the shift points.

I drained roughly 3 quarts......in the end added back 6.5 quarts. Conclusion, the fluid was about 3.5 quarts low. The truck had 106,xxx miles when I did the service.

Be careful of the mythconceptions about fluid, grit, sludge......etc you read. Suggest to follow the Service Schedule in the Owner's Manual. I know my 2nd Gen recommends this service every 100k.

 

Thanks for the responses. I have that slight shudder thing between 30-45 mph that seems to be kind of normal with these trucks and was considering the drain and fill option to see if it goes away.

But it shifts smooth so I think I'll leave it alone for now.

I appreciate the advice.

 

I would just do a drain and fill. The correct level is what makes a difference and could be the reason behind your shutter. Just make sure it’s properly filled and that will require a drain and fill.

 

Bob, read up on these two threads. These are the main options for the DIY'er. Full flush, or drain and fill. A lot of folks will opt to do several drain and fills over the course of a few months. Flushes most of the old fluid out over time.
https://www.tacomaworld.com/threads/diy-full-flush-for-automatic-transmission.68462/
https://www.tacomaworld.com/threads...e-2nd-gen-transmission-pan-and-filter.726329/

All that being said, you may consider checking the carrier bearing first (if your truck even has one). I can never remember which models did and which didnt. That has been known to cause vibrations when the rubber wears out

 

That's ironic. I was just driving back from getting some copper plugs from the dealer and thought of drain and fill with about 100 miles between each. I saw a YouTube vid that showed it took about 4 drain and fills.

I was gonna ask that same question here.

I think that's what I'm gonna do to create a slower transition to newer fluid.

I've read most in those threads you linked.

The front and middle u-joints are pretty new. The rear joint is most likely original. The carrier bearing is centered and has no play that I can tell.

I did the brake tap check and the shudder remained.

I serviced rear differential this morning.

Thank you for the advice. The shudder isn't that bad, so I'm gonna slowly change out transmission fluid and go from there.

 

Does this stuff work or is it just a bandaid?

 

I know I read something in one of the many threads on this shudder about an additive.

Is this stuff ^^^ it?

I'm planning on a multiple drain and fill over time and want to know if this additive is recommended?

 

Pop the transmission pan off please lol , Then do some reading before you start
https://www.tacomaworld.com/threads...e-2nd-gen-transmission-pan-and-filter.726329/

https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

I've already read about 4 hours of these threads in this forum concerning the shudder. One of the two you posted I've read and it recommended the lube gard I asked about.

For what it's worth, I have the shudder in or out of overdrive, so that part of the thread is useless.

Brake tap check at temp didn't change anything.

I've already cleaned the throttle body that your threads spoke about and no change. I'm planning on doing drain and fill, as I posted above next. I'm gonna go about 100 miles between 4 different drain and fills with the pan and filter done on that last step.

Trust me, I've been reading in here. A lot.

I just remembered reading some posts about this additive and wanted confirmation it's ok.

Now that I read again in one of your links that it's ok, I'm gonna add one with each drain and fill. Thanks for that as that was my question.

If your wondering why I'm going 100 miles between 4 drain and fills, read my op and subsequent posts. It was based on something my local dealer said.

If you think it's silly as a first step before solenoids, please tell me. I can wrench on A-7's, A-6's, A-4's and F/A-18's and can follow manuals on a lot of car stuff. But I bought this truck a month ago, it had 247k miles and I am in the process of setting a maintenance baseline with fluids, filters and general maintenance.

The shudder is the only thing wrong with it and I'm now turning my attention towards it as I'm almost finished with the baseline.

 

I honestly do not remember recommending the instant shudder fix as I have never used it .
Lubeguard Platinum is the stuff I recommend , however other members on here have used the stuff you displayed above with excellent results .
I may have mentioned to use both in other posts .

What I think is silly as a first step is adding new transmission fluid with super detergents to a dirty transmission pan with 247 K ,which will lift all the crap off your magnets and possibly plug your solenoids .
This is why I posted the link to a proper transmission service as I didn't want to see you get caught with grief

If your torque converter locking clutch is the cause of the shudder , a brake tap test will prove it . You can actually watch the brake switch command the converter to unlock if you have a quality scanner . If the brake tap test didnt make the shudder go away , I doubt its trans related

 

Brake tap test didn't change a thing.

What do you think about adding too much new fluid at once? After what the dealer guy said, I thought a slower process would be better.

One more question. I was reading one of your links just now and linked into how to enter temp check mode. There's a video showing how to do it. But there's a comment that says "Assuming you don't have a prerunner, follow steps in video."

I have a prerunner.

Is there a different way to enter temp check mode on a prerunner?

 

I never use check mode . I just use a temp gun

What kind of scanner are you using ? got any codes ?

At 247K You may have a stretched timing chain .
https://www.youtube.com/watch?v=UR50da0sDOc&t=61s

 

No codes. Just the shudder. Previous owner did timing chain replacement, so that should be good.

Was gonna use temp gun until I saw jumper vid. Now I'm leaning back to gun...lol

Saw a video comparison with temp gun and a software package on YouTube.

Looks like temp gun reads 3-4 degrees less as a gauge of when the trans enters the proper temp range for checking proper fill.

That about right?

 

I think I'll go ahead and do the pan and filter on first drain and fill to eliminate the crap in the pan.

What's your thoughts on the 100 miles between 4 drain and fills?

 

Ahh glad the timing chain is out of the way . Those chains can cause shuddering without any codes or baby missfires that the computer in your truck cant detect .

Temp gun is fine . 3-4 degrees doesnt make a difference with fluid expansion . As long as your overflow tube is dribbling with the truck running and transmission near 100 to 115 , you are good to go

 

That sounds like the perfect plan ! You will know better once you have the transmission pan and screen off