Complete Transmission Flush DIY - VIDEO

[RT Cruiser]

Thanks for the video and confirmation when to pull the jumper.

I am successful in getting into temperature detection mode. My main point of confusion was when to pull the pin holding the thermostat open and when to pull the jumper in the OBD connector.

Looks like I can remove the thermostat pin once the flush is complete as it is not needed for the temperature / level check.

And as you mention, pull the OBD jumper once in park with temperature detection mode active.

Regarding the blinking lights, I do see it mentioned in this post when using Techstream, so probably normal with the jumper method as well.

A/T fluid change procedure help

forum.ih8mud.com

View attachment 3701409

It's much easier than what it can first be observed from the video. Your transmission should shift like butter now.

 

[fcigoj]

Hi all,

I need to pick your brain, rather urgently in fact.
I had a workshop perform the transmission flush due to lack of space to do it myself.
Now the transmission overheats severely, to the point of getting to 115 deg C idling in a queue and affecting the temperature of the engine cooling fluid.
Has some of you noticed anything similar ? And, more importantly, any idea of why it is doing it ?
The car has never overheated before, and it got me really nervous.
Also, they invoiced me 10 liters of ATF oil, which seems way below the capacity. Is the level too low ?
I would love to give the workshop the procedure to measure the level, but I would need it on paper. Can some of you throw a PDF my way please ? Sorted

Grateful for any help

 

[KLF]

I did a 4 quart dump-and-fill yesterday on mine ('15 LC, 115K miles), pretty sure it still had the factory fluid. The stuff that came out was very dark.

I used the procedure from the FSM, it told me to leave the pin in the tstat until the test/level check was all done, so that's what I did.

I don't have access to Techstream, my old WinXP laptop died a few years ago, haven't bothered to get it setup on my current laptop, so I did the jumper in the OBD port method. Temp test worked perfectly, very easy to do, and I also left the jumper installed for the entire test, removed after I was done and shut the engine off.

Haven't driven it yet, still up on the lift, doing new SS brake lines and brake system flush today.

Really wish we just had a dipstick, would make checking and filling so much easier...

 

[Artie]

Tomorrow will be my first go at this service on my 2021 8 speed. Having read through this thread and watched the videos I think I have a pretty good grasp on the mechanical aspect of the process but the final fluid level check is where I get antsy.

I don’t have to do the jumpers or the gear shift back and forth thing to enter the ATF level adjust mode if I’m using OBD fusion, correct? As soon as the trans temp is between 102°-115° I’m good to check the level and close it all up, correct?

 

[prharper]

Tomorrow will be my first go at this service on my 2021 8 speed. Having read through this thread and watched the videos I think I have a pretty good grasp on the mechanical aspect of the process but the final fluid level check is where I get antsy.

I don’t have to do the jumpers or the gear shift back and forth thing to enter the ATF level adjust mode if I’m using OBD fusion, correct? As soon as the trans temp is between 102°-115° I’m good to check the level and close it all up, correct?

Correct with your 2021.

 

[Artie]

Wrapping up this task now but wanted to get the thumbs up from those wiser than I before I put the skids back on.

Did the drain refill 3 times. First drain was 3200ML, next 2 were 2500z. I replaced the same amount that came out. Ran until trans pan temp was 106 and pulled the plug until it was sporadically dripping then buttoned it all up.

All this sound about right?

All the ambiguity in the level check makes me over think it all…. Damn, I miss dipsticks!

 

[prharper]

Wrapping up this task now but wanted to get the thumbs up from those wiser than I before I put the skids back on.

Did the drain refill 3 times. First drain was 3200ML, next 2 were 2500z. I replaced the same amount that came out. Ran until trans pan temp was 106 and pulled the plug until it was sporadically dripping then buttoned it all up.

All this sound about right?

All the ambiguity in the level check makes me over think it all…. Damn, I miss dipsticks!

Sounds right. Congrats!

 

[04UZJ100]

Tomorrow will be my first go at this service on my 2021 8 speed. Having read through this thread and watched the videos I think I have a pretty good grasp on the mechanical aspect of the process but the final fluid level check is where I get antsy.

I don’t have to do the jumpers or the gear shift back and forth thing to enter the ATF level adjust mode if I’m using OBD fusion, correct? As soon as the trans temp is between 102°-115° I’m good to check the level and close it all up, correct?

Does that temp measure the output of the torque converter or the pan? There are two temp probes.

You need the fluid in the PAN to be at temp. The fluid output from the torque converter is not representative or correct for the procedure.

 

[Artie]

Does that temp measure the output of the torque converter or the pan? There are two temp probes.

You need the fluid in the PAN to be at temp. The fluid output from the torque converter is not representative or correct for the procedure.

My fusion layout has both and I was paying attention to the pan.

 

[UGN]

Hi all,

I need to pick your brain, rather urgently in fact.
I had a workshop perform the transmission flush due to lack of space to do it myself.
Now the transmission overheats severely, to the point of getting to 115 deg C idling in a queue and affecting the temperature of the engine cooling fluid.
Has some of you noticed anything similar ? And, more importantly, any idea of why it is doing it ?
The car has never overheated before, and it got me really nervous.
Also, they invoiced me 10 liters of ATF oil, which seems way below the capacity. Is the level too low ?
I would love to give the workshop the procedure to measure the level, but I would need it on paper. Can some of you throw a PDF my way please ? Sorted

Grateful for any help

I did a quick search online and found this article The Dangers of an Overheating Transmission | Ralph's Transmission

"A lack of fresh transmission fluid (or using the wrong type of fluid for your transmission) is the most common cause of transmission problems like overheating."

I would confirm with the shop they did use Toyota WS ATF and check for the correct amount of fluid with the temperature check.

 

[fcigoj]

I did a quick search online and found this article The Dangers of an Overheating Transmission | Ralph's Transmission

"A lack of fresh transmission fluid (or using the wrong type of fluid for your transmission) is the most common cause of transmission problems like overheating."

I would confirm with the shop they did use Toyota WS ATF and check for the correct amount of fluid with the temperature check.

In fact I went back to the workshop the following morning and they fixed simply checking the level using the right procedure and adding the missing fluid.

 

[Artie]

In fact I went back to the workshop the following morning and they fixed simply checking the level using the right procedure and adding the missing fluid.

Having just done my service I can confirm that the level check process is less than desirable.

I’m glad that you got it sorted out.

 

[fcigoj]

Having just done my service I can confirm that the level check process is less than desirable.

I’m glad that you got it sorted out.

Me too, believe me.
Touching wood, I never had trouble with the transmission before and I only flushed it out caution, so I would have hated to introduce issues by doing so.
Now all is good, and will soon install an external cooler from Wholesale because the vehicles sold in Europe didn´t come with the external cooler, and only the line through the bottom of the radiator is there, which proves insufficient at times in summer heat.
So, fingers crossed...

 

[hbar]

LOL .. Check point charlie sign.

There has been some discussions on how much of that older fluid should remain as it contains needed clutch particles. Some say to not change it too often for this reason.

I've rebuilt my fair share of automatics, including a couple Aisins (though never one out of a LC), and find that sort of reasoning to be questionable at best. Fresh fluid doesn't have any of those "clutch particles" in it, and under normal use the frictions in the transmission experience very little wear. It's not uncommon to open one up for a rebuild and find that the clutches look absolutely new, with the printing still on the surface. Now if it overheats or starts slipping, then all bets are off. Burned frictions & steels will show obvious wear and need to be replaced, but at that point you were already slipping and/or smelled burnt fluid, and that's why you're rebuilding it.

But if your transmission needs the cast-off friction material suspended in the fluid to operate properly, then you have an overhaul in your near future, and I would bet you're running hot. The old wive's tale of "don't change your trans fluid after a certain age because it will break your transmission" is just that. You were on your last leg anyway if fresh fluid is what did you in. Rather, fresh/clean fluid ensures that the clutches slip freely when not engaged, and grab firmly & quickly when they do engage. Never mind that the valve body wants clean fluid to ensure that the valves move freely in the bores. Enough gunk will cause valves to stick and all sorts of strange behavior. I mean, would you not change your motor oil for fear of the dirt in the old oil being responsible for your piston rings sealing well?

btw, I hope it's not on my LC, but I'm legit looking forward to rebuilding one of these units. If yours dies, HMU.

 

[Fisher23]

I've rebuilt my fair share of automatics, including a couple Aisins (though never one out of a LC), and find that sort of reasoning to be questionable at best. Fresh fluid doesn't have any of those "clutch particles" in it, and under normal use the frictions in the transmission experience very little wear. It's not uncommon to open one up for a rebuild and find that the clutches look absolutely new, with the printing still on the surface. Now if it overheats or starts slipping, then all bets are off. Burned frictions & steels will show obvious wear and need to be replaced, but at that point you were already slipping and/or smelled burnt fluid, and that's why you're rebuilding it.

But if your transmission needs the cast-off friction material suspended in the fluid to operate properly, then you have an overhaul in your near future, and I would bet you're running hot. The old wive's tale of "don't change your trans fluid after a certain age because it will break your transmission" is just that. You were on your last leg anyway if fresh fluid is what did you in. Rather, fresh/clean fluid ensures that the clutches slip freely when not engaged, and grab firmly & quickly when they do engage. Never mind that the valve body wants clean fluid to ensure that the valves move freely in the bores. Enough gunk will cause valves to stick and all sorts of strange behavior. I mean, would you not change your motor oil for fear of the dirt in the old oil being responsible for your piston rings sealing well?

btw, I hope it's not on my LC, but I'm legit looking forward to rebuilding one of these units. If yours dies, HMU.

How often (every how many miles) would you change the trans fluid with a full flush, if towing light fairly frequently (under 3000 lbs) ?

 

[KLF]

I'm very pleased at how much better mine runs/feels even after doing only a 4 quart dump and fill. The old fluid was very dark. It just seems to "pull" better on acceleration, and shifts are crisper.

 

[hbar]

How often (every how many miles) would you change the trans fluid with a full flush, if towing light fairly frequently (under 3000 lbs) ?

I don't know that I can give a good recommendation based on miles. In my experience (I don't do this professionally although people have paid me to rebuild), it's much more related to abuse & temperature than just miles. If you're just doing towing well under the rated limit and mild stuff off-road (i.e. no deep mud, no rock crawling, no sand) then I would think 60k miles is the first time I would really start thinking about fluid change. But I'm not a Toyota engineer so don't trust me! The first level test is always to drain the fluid and see what it looks like. If it's red & "fairly clear," send it.

I'm new to the LC game, but I wheel jeeps (and plan to use my LC to tow my jeep to the place)...they use ATF+4 and if mine sees 240F I'm changing it when I get home, and I would probably do a full flush. I don't yet know what the breakdown temp is for whatever fluid we have to use. But for normal use, I tend to err on the side of just doing the pan drop & filter replace. BTW, it seems pretty insane -to me- that it is recommended to not change the filter or even to drop the pan. Now if that fluid comes out like what I've seen in some of these videos, it's a full flush for sure and I couldn't fathom not dropping the pan & replacing the filter.

But given that it's something of a hassle to add fluid anyway, I'm not sure that the full flush isn't just worth the minor additional effort anyway. I guess it comes down to how hard it is to identify the pressure side line to the cooler & then how hard is it to get at that hose clamp.

I'm also a little surprised that people here aren't running their own temperature gauge, esp given how much time y'all seem to spend in the sand and towing houses etc. I know you can read various temps off Torque or whatever, but there's no substitute for a sender in the pan & a gauge on the dash.


But hey, I don't mean to show up here on week 1 of ownership with my 10 posts on the forum and spout off like I'm some sort of transmission expert. But the truth is I've been inside a more than a few, and watched teardowns of MANY others....they're all basically the same. Snap rings, clutches, and planetary gearsets. Fluid pressure selectively applies clutch packs to give you the correct gear ratio. It all relies on your fluid being clean enough.

 

[Artie]

I don't know that I can give a good recommendation based on miles. In my experience (I don't do this professionally although people have paid me to rebuild), it's much more related to abuse & temperature than just miles. If you're just doing towing well under the rated limit and mild stuff off-road (i.e. no deep mud, no rock crawling, no sand) then I would think 60k miles is the first time I would really start thinking about fluid change. But I'm not a Toyota engineer so don't trust me! The first level test is always to drain the fluid and see what it looks like. If it's red & "fairly clear," send it.

I'm new to the LC game, but I wheel jeeps (and plan to use my LC to tow my jeep to the place)...they use ATF+4 and if mine sees 240F I'm changing it when I get home, and I would probably do a full flush. I don't yet know what the breakdown temp is for whatever fluid we have to use. But for normal use, I tend to err on the side of just doing the pan drop & filter replace. BTW, it seems pretty insane -to me- that it is recommended to not change the filter or even to drop the pan. Now if that fluid comes out like what I've seen in some of these videos, it's a full flush for sure and I couldn't fathom not dropping the pan & replacing the filter.

But given that it's something of a hassle to add fluid anyway, I'm not sure that the full flush isn't just worth the minor additional effort anyway. I guess it comes down to how hard it is to identify the pressure side line to the cooler & then how hard is it to get at that hose clamp.

I'm also a little surprised that people here aren't running their own temperature gauge, esp given how much time y'all seem to spend in the sand and towing houses etc. I know you can read various temps off Torque or whatever, but there's no substitute for a sender in the pan & a gauge on the dash.


But hey, I don't mean to show up here on week 1 of ownership with my 10 posts on the forum and spout off like I'm some sort of transmission expert. But the truth is I've been inside a more than a few, and watched teardowns of MANY others....they're all basically the same. Snap rings, clutches, and planetary gearsets. Fluid pressure selectively applies clutch packs to give you the correct gear ratio. It all relies on your fluid being clean enough.

As far as temps go, I hit 240° almost every time I tow and I tow often.

 

[hbar]

As far as temps go, I hit 240° almost every time I tow and I tow often.

Right, but I specifically mentioned that number in the context of a transmission/fluid that I’m more familiar with. Sorry if that wasn’t more clear.

 

[hbar]

Right, but I specifically mentioned that number in the context of a transmission/fluid that I’m more familiar with. Sorry if that wasn’t more clear.

What digging around I have done turned up some threads on Tundras & Tacos and other transmissions that use the same ATFWS we use. Of particular note is a reply somebody got from Toyota themselves about at what temperature the trans temp idiot light goes on.... they said it was at 300F. That's hotter than I've ever heard ATF getting, and the general notion I've read elsewhere is that by the time that light goes on it may be too late. I can smell that fluid now.

Anecdotally, it seems like other Toyota owners on other forums feel like 240F is "dangerously" hot. So, @Artie - (a) for how long do you maintain/exceed 240F while towing, (b) how often do you change your fluid, (c) what's your fluid smell like, and (d) do you have an aux transmission cooler?

I'm interested to learn what the actual temperature bounds are. I'll be towing my jeep through the treacherous hills of southern MO in a few weeks, I'll definitely be monitoring my temp as I go.