GX460 Transmission fluid cooler (5 Viewers)

[Rednexus]

I actually dis

I know people reuse them but as a retired Navy Chief Machinist Mate can't bring myself to do it. Especially when the tech manual specifies to use a new one and the edges of the old one have been crushed already. Hell if I caught one of my men using an Oklahoma socket set (crescent wrench) I'd threaten to beat them with it, I don't need any round head bolts in MY Engine Room. Then I'd go topside and throw it overboard.

But the Chief may have always kept one in his locker, I will neither confirm nor deny. Because 3/4" wrenches on a ship = 10mm on a Toyota LOL. And an ACE hardware store was always a very long ways away.

I share the disdain for crescent wrenches . I actually didn't own one for at least a decade; I do have one now but use it maybe 1X-2X a year tops.

TBH I didn't know replacing metal crush washers was a "thing" - coming from the Subaru world they are very rarely replaced for oil pans and filters - but folks over here in Yota land to seem to replace them frequently. I did replace them the first time I changed fluids and have spares sitting around for just-in-case.

 

[Acrad]

Not sure when I went to using new washers versus re-use on my earlier Ford, Infiniti, Nissan or Mazdas.... honorable mention 2-stroke '84 Mitsubishi Cordia Turbo... a long time ago

.. probably been 20 years I guess

 

[RJinVA]

I know people reuse them but as a retired Navy Chief Machinist Mate can't bring myself to do it. Especially when the tech manual specifies to use a new one and the edges of the old one have been crushed already. Hell if I caught one of my men using an Oklahoma socket set (crescent wrench) I'd threaten to beat them with it, I don't need any round head bolts in MY Engine Room. Then I'd go topside and throw it overboard.

But the Chief may have always kept one in his locker, I will neither confirm nor deny. Because 3/4" wrenches on a ship = 10mm on a Toyota LOL. And an ACE hardware store was always a very long ways away.

3/8"......you're welcome. Signed - Former Army Grunt

 

[RJinVA]

Installed a Hayden 678 this weekend along with doing a complete transmission flush. My 45k mile 2019 seemed fine but I recently towed a 5k pound trailer halfway across the country and wanted to change out the fluid for peace of mind. In all honesty the fluid looked worse than I thought it would but the GX seemed to shift okay. During that cross country drive temps never exceeded 210 degrees and normal driving during my morning commute has shown consistent 180-190 degree AT fluid temps. After adding the cooler I'm seeing 155 degrees during my morning commute. Transmission is shifting great post flush. (Edit to fix trans temp number)

 

[jeremy j]

Installed a Hayden 678 this weekend along with doing a complete transmission flush. My 45k mile 2019 seemed fine but I recently towed a 5k pound trailer halfway across the country and wanted to change out the fluid for peace of mind. In all honesty the fluid looked worse than I thought it would but the GX seemed to shift okay. During that cross country drive temps never exceeded 205 degrees and normal driving during my morning commute has shown consistent 180-190 degree AT fluid temps. After adding the cooler I'm seeing 155 degrees during my morning commute. Transmission is shifting great post flush.
View attachment 3630860

Do you have the thermostat pinned open? I ask because I added the Hayden cooler and see about 190 pan temps after it fully heats up. Ambient temps have been about 80 degrees when testing this. I haven't towed with it yet to see how it does. I have been monitoring the TC temps too and those have hit 220 or so when I was trying to drive them up while accelerating up a long incline with the TC unlocked.

I do sometimes see the temps rapidly drop (mainly TC temp) even under load so I assume it is the thermostat opening. I haven't been able to pin point when the thermostat opens yet though.

@Acrad have you found a way to monitor the thermostat with the Fusion software?

 

[RJinVA]

Do you have the thermostat pinned open? I ask because I added the Hayden cooler and see about 190 pan temps after it fully heats up. Ambient temps have been about 80 degrees when testing this. I haven't towed with it yet to see how it does. I have been monitoring the TC temps too and those have hit 220 or so when I was trying to drive them up while accelerating up a long incline with the TC unlocked.

I do sometimes see the temps rapidly drop (mainly TC temp) even under load so I assume it is the thermostat opening. I haven't been able to pin point when the thermostat opens yet though.

@Acrad have you found a way to monitor the thermostat with the Fusion software?

I do not have the thermostat pinned open nor do I know how to monitor it. I'm assuming it's a purely mechanical system with no digital feedback. I was surprised how cool my trans temps stayed while towing that 5k trailer from DC to Kansas City, even going over the Appalachian mountains it never went higher than 210 degrees.

 

[r2m]

I do not have the thermostat pinned open nor do I know how to monitor it. I'm assuming it's a purely mechanical system with no digital feedback. I was surprised how cool my trans temps stayed while towing that 5k trailer from DC to Kansas City, even going over the Appalachian mountains it never went higher than 210 degrees.

What was the outside temperature when you did the screen shot?

 

[RJinVA]

What was the outside temperature when you did the screen shot?

Low to mid sixties probably

 

[suitcase]

Installed a Hayden 678 this weekend along with doing a complete transmission flush. My 45k mile 2019 seemed fine but I recently towed a 5k pound trailer halfway across the country and wanted to change out the fluid for peace of mind. In all honesty the fluid looked worse than I thought it would but the GX seemed to shift okay. During that cross country drive temps never exceeded 210 degrees and normal driving during my morning commute has shown consistent 180-190 degree AT fluid temps. After adding the cooler I'm seeing 155 degrees during my morning commute. Transmission is shifting great post flush. (Edit to fix trans temp number)

Are you running any after-market skid plates that coverup the transmission? I installed an OEM AT cooler in my '17. My AT pan temps hover around 200F and this is in mild temps, say 70F, and not pulling anything. I do, however, have a full set of skids. The mid-skid covers up the transmission pan. I'm wondering if I should just leave that mid-skid off for daily driving. There's one bolt though that's a pain to access. Every time I read a thread reporting AT temps it seems like mine are on the high side even with an AT cooler. I just did another simple AT drain/refill. It had been about 10k miles since the last drain/refill, but the AT fluid still looked nice and red.

 

[RJinVA]

Are you running any after-market skid plates that coverup the transmission? I installed an OEM AT cooler in my '17. My AT pan temps hover around 200F and this is in mild temps, say 70F, and not pulling anything. I do, however, have a full set of skids. The mid-skid covers up the transmission pan. I'm wondering if I should just leave that mid-skid off for daily driving. There's one bolt though that's a pain to access. Every time I read a thread reporting AT temps it seems like mine are on the high side even with an AT cooler. I just did another simple AT drain/refill. It had been about 10k miles since the last drain/refill, but the AT fluid still looked nice and red.

Yes I have a full set of ARB skid plates. For whatever reason my GX trans tends to run very cool but I will say that I drive like an old man....

 

[Cold Iron]

Are you running any after-market skid plates that coverup the transmission? I installed an OEM AT cooler in my '17. My AT pan temps hover around 200F and this is in mild temps, say 70F, and not pulling anything. I do, however, have a full set of skids. The mid-skid covers up the transmission pan. I'm wondering if I should just leave that mid-skid off for daily driving. There's one bolt though that's a pain to access. Every time I read a thread reporting AT temps it seems like mine are on the high side even with an AT cooler. I just did another simple AT drain/refill. It had been about 10k miles since the last drain/refill, but the AT fluid still looked nice and red.

19 with 43K and I too wondered how come mine ran so warm compared to most others posted on here, mine is normally in your range no cooler installed (yet) no skids. After @RJinVA posted his Fusion pic I did a quick search and found a thread on the Tundra forums where people are having similar differences in temps. The general thought is that the wax poppet valve (Tstat) can vary from 10-12° between vehicles. Being a mechanical valve with no electromagnetic input or sensors there is no way to monitor it in Fusion unless a sensor is installed in line, which there isn't except at TC and sump.

After my trip this weekend to North Chicago not going to wait before towing to get a benchmark value to install the Hayden 698 on mine, I'm ordering the ATF tonight to do the install and of course drain and fill. I-90 75 mph extremely strong winds ambient air mid 60's held between 211-218° both ways even coming back going up the bluffs into Mn. But in the Chicago traffic sitting at lights and no air movement 219-221° was common at TC then eventually the pan was rising. The sump likes air flow no doubt about it, not sitting still.

If it was me and I lived in the Bay area with all that traffic and mild winter temps I would pin the stat open and leave it open all year, that would have to be a personal decision of course. For me I am going to leave it pinned open in the summer but also went with the 698 because it has a Tstat so if I don't get a chance to unpin the engine Tstat before a cold snap hits it will still warm up the ATF some. Just hope the 698 Tstat set point is lower than the OEM.

 

[suitcase]

19 with 43K and I too wondered how come mine ran so warm compared to most others posted on here, mine is normally in your range no cooler installed (yet) no skids. After @RJinVA posted his Fusion pic I did a quick search and found a thread on the Tundra forums where people are having similar differences in temps. The general thought is that the wax poppet valve (Tstat) can vary from 10-12° between vehicles. Being a mechanical valve with no electromagnetic input or sensors there is no way to monitor it in Fusion unless a sensor is installed in line, which there isn't except at TC and sump.

After my trip this weekend to North Chicago not going to wait before towing to get a benchmark value to install the Hayden 698 on mine, I'm ordering the ATF tonight to do the install and of course drain and fill. I-90 75 mph extremely strong winds ambient air mid 60's held between 211-218° both ways even coming back going up the bluffs into Mn. But in the Chicago traffic sitting at lights and no air movement 219-221° was common at TC then eventually the pan was rising. The sump likes air flow no doubt about it, not sitting still.

If it was me and I lived in the Bay area with all that traffic and mild winter temps I would pin the stat open and leave it open all year, that would have to be a personal decision of course. For me I am going to leave it pinned open in the summer but also went with the 698 because it has a Tstat so if I don't get a chance to unpin the engine Tstat before a cold snap hits it will still warm up the ATF some. Just hope the 698 Tstat set point is lower than the OEM.

I wasn't too rigorous in collecting temp data pre/post AT cooler, pre/post skids, etc., but I think the cooler dropped the temps by about 10F. I also see higher temps in city driving w/ lots of stop and go vs. hwy driving.

 

[Acrad]

It's a mechanical thermostat so just monitoring via the pan and TC outflow temps on those two sensors.

I never got around to trying to determine the exact temp thermostat opens and closes. It's just been pinned open for years now.

 

[SpitnTears]

Are you running any after-market skid plates that coverup the transmission? I installed an OEM AT cooler in my '17. My AT pan temps hover around 200F and this is in mild temps, say 70F, and not pulling anything. I do, however, have a full set of skids. The mid-skid covers up the transmission pan. I'm wondering if I should just leave that mid-skid off for daily driving. There's one bolt though that's a pain to access. Every time I read a thread reporting AT temps it seems like mine are on the high side even with an AT cooler. I just did another simple AT drain/refill. It had been about 10k miles since the last drain/refill, but the AT fluid still looked nice and red.

I have a '17 w/ the OEM AT cooler. Similar temps. Maybe slightly lower. Similar ambient temp. OEM skids.

I wasn't too rigorous in collecting temp data pre/post AT cooler, pre/post skids, etc., but I think the cooler dropped the temps by about 10F. I also see higher temps in city driving w/ lots of stop and go vs. hwy driving.

It seemed like similar temp drops when I added my OEM cooler.

I'm contemplating going to a Hayden 698

 

[jdam]

It's done. 45,000 mile fluid. The install itself wasn't too bad but I cut up my hands pretty bad trying to reach all the hose clamps deep in the hole. Removing the battery helped, as well as reaching from underneath. The ARB skids get in the way so had to remove the front one too.

 

[thescreensavers]

It's done. 45,000 mile fluid. The install itself wasn't too bad but I cut up my hands pretty bad trying to reach all the hose clamps deep in the hole. Removing the battery helped, as well as reaching from underneath. The ARB skids get in the way so had to remove the front one too.

View attachment 3645379

Check out the Milwaukee cut level 1 gloves at home Depot. They help tremendously with small cuts and scrapes and you don't really loose dexterity.

 

[jonshonda]

Towed the camper for the first time this season (4800lb 19ft Rockford Roo Hybrid brick), Lexus loaded with the wife, kids, two 80lb yellow labs, and two wheel barrows full of oak firewood in the Thule cargo box on the Victory roof rack. Trans temps almost always matched coolant temps with the Hayden cooler installed, so mid 190's with a few spikes when short punchy hills were involved. Converter temps did get into the 220's, but came down very quickly when the grade leveled out.

This is a 2017 Luxury, 67k miles with a full trans fluid exchange done at 60k miles with OEM fluid. If I remember correctly the GX470 trans temps hovered around 180-185* pulling the same setup with Hayden cooler.

 

[rav8]

Towed the camper for the first time this season (4800lb 19ft Rockford Roo Hybrid brick), Lexus loaded with the wife, kids, two 80lb yellow labs, and two wheel barrows full of oak firewood in the Thule cargo box on the Victory roof rack. Trans temps almost always matched coolant temps with the Hayden cooler installed, so mid 190's with a few spikes when short punchy hills were involved. Converter temps did get into the 220's, but came down very quickly when the grade leveled out.

This is a 2017 Luxury, 67k miles with a full trans fluid exchange done at 60k miles with OEM fluid. If I remember correctly the GX470 trans temps hovered around 180-185* pulling the same setup with Hayden cooler.

That's about how mine acts, minus a few hundred pounds, dogs and firewood. Transmission temps match engine coolant until we start uphill for a ways. You can see the temp drop briefly as the valve opens and lets the fluid into the radiator and trans cooler. The highest my temps have reached since installing are 212F while towing our camper.

 

[jonshonda]

That's about how mine acts, minus a few hundred pounds, dogs and firewood. Transmission temps match engine coolant until we start uphill for a ways. You can see the temp drop briefly as the valve opens and lets the fluid into the radiator and trans cooler. The highest my temps have reached since installing are 212F while towing our camper.

Yeah overall I am very happy with how it tows with regards to operating within normal parameters. I don't off-road with the Lexus, but I do depend on to perform when needed and both the GX470 and now the GX460 are performing as expected.

 

[GXFamily]

The Hayden 698 has a 180degree thermostat according to their tech department.

I'm on the fence between the 698 and 678.

I have the OEM cooler installed and the factory thermostat pinned. 90+ ambient temp I have a pan temp of 190-195deg; it always matches the coolant temp.

I am aiming to get it around 175-180 tops.