GX460 Transmission fluid cooler (7 Viewers)

[Rednexus]

That’s a significant improvement even with the “small” OEM cooler. That suggests that maybe it’s not too difficult to keep temps in check if almost any cooler is added.

On flat ground or rolling terrain around the Midwest, yes. If you are pulling a long grade where the TCC is unlocked for more than a few minutes (in 3rd gear or below), you can have runaway temps where the small OEM cooler cannot really keep up. I've experienced this even under low-throttle conditions when driving out West, pulling paved grades unloaded at 25-40 mph (with the speed based on the road being curvy). If you are towing in hillier areas of the Midwest, you may also end up having the same problem.

If you are not driving out West or towing, the OEM cooler is probably fine for normal driving conditions. It was for my rig until the first time I took it to CO. But, a larger cooler is actually cheaper than a OEM cooler anyway and will provide better performance if the rig is used hard.

 

[Chewyeti]

Very awesome thread (I've now read it end to end twice lol).

2018 460 with mild lift, E rated 265/70/70 BFG's, sliders and ARB Skids. Just did a drain/fill/filter at 65k miles. I'm the second owner, but got it at 19,000 miles. Fluid was dark, still sort of translucent, almost had a red-purple hue to it.

After the drain/fill (Watched the GXBOB video) I started monitoring the AT Temp 1 and 2 sensors. In every day driving, AT-1 hovers around 190-195 (70-80mph, TC locked, ambient 60-80F outside). I do off-road, and I tow a mild (1500lb maybe? trailer on occasion). Sitting near 200F in regular conditions seems high for AT fluid, but in reading this thread, the factory thermostat to the radiator may not even open until ~200F?

Looking at doing the OEM cooler for piece of mind.

Questions for the collective:
1) OEM Denso cooler or an OEM replacement like KYORAD from rockauto? ($90 vs $250-400).
2) When doing the drain/fill - the GXBOB video didn't mention pinning open the thermostat. Worth doing the level set again with that open?
3) Define "a trickle" when setting the AT fluid level. I'm guessing I'm slightly overfilled.

 

[Acrad]

IMO.. need to monitor AT temp and also torque converter engagement. I tow as well and even with the small cooler if you monitor the data you can often change your driving behavior to influence the temps. If I see temps creeping up I will pull back in attempt to get back into lockup which will cools things off significantly. Bear in mind.. I’m in the 2k-3K towing club… I don’t tow beyond that with my 460.

 

[Rednexus]

IMO.. need to monitor AT temp and also torque converter engagement. I tow as well and even with the small cooler if you monitor the data you can often change your driving behavior to influence the temps. If I see temps creeping up I will pull back in attempt to get back into lockup which will cools things off significantly. Bear in mind.. I’m in the 2k-3K towing club… I don’t tow beyond that with my 460.

The Wholesale Automatics TCC manual lockup switch I have in my 470 is also quite nice for that. I can override the ECM to lock the TCC in any gear and keep the temps down. It's really nice for long, sustained climbs, such as when towing our 4K# camper. I'm not sure if it's available for a 460 or not - it might be a 470-only item, since it has an electronic module that requires splicing into the ECM harness to get it to work.

However, the manual TCC lock isn't appropriate for every situation. It's not good if you are in a high-throttle application (where it might damage the TCC itself) or a long off-road climb where the damping properties of a unlocked TCC are needed. My trans will still get up to around 215-220F on long off-road climbs out West (i.e., going up for several miles at 5-10 mph), where I'm not willing to lock the TCC, even with the larger Hayden 678 cooler. With the smaller OEM cooler I think the AT temp would end up well above 250F on a climb like that.

 

[evolute]

Can you post some pics of how it is installed, horn relocation, etc? What are your temps running.

Also, it is not $500 USD. It is AUD. Closer to around $280ish, depending on the currency conversion at the time of purchase.

Sure thing. Temps wise I haven’t seen anything over 165, but I’m also in Florida and the temp outside has been in the 50s-60s and I have my thermostat/warmer pinned open. I am interested in gathering data during the hot Florida summer.

 

[GXFamily]

Sure thing. Temps wise I haven’t seen anything over 165, but I’m also in Florida and the temp outside has been in the 50s-60s and I have my thermostat/warmer pinned open. I am interested in gathering data during the hot Florida summer.

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I have the OEM plumbing for a cooler installed on my 460 as well. This may work well.

I decided to pick up a Hayden *698 with the bypass. The thermostat on the cooler is at 180deg according to Hayden. This will allow me to keep the thermostat pinned open and maintain close to operating temperatures. Most of my driving is short trips and 170-180 seems to be the sweet spot for the A760.

 

[suitcase]

Very awesome thread (I've now read it end to end twice lol).

2018 460 with mild lift, E rated 265/70/70 BFG's, sliders and ARB Skids. Just did a drain/fill/filter at 65k miles. I'm the second owner, but got it at 19,000 miles. Fluid was dark, still sort of translucent, almost had a red-purple hue to it.

After the drain/fill (Watched the GXBOB video) I started monitoring the AT Temp 1 and 2 sensors. In every day driving, AT-1 hovers around 190-195 (70-80mph, TC locked, ambient 60-80F outside). I do off-road, and I tow a mild (1500lb maybe? trailer on occasion). Sitting near 200F in regular conditions seems high for AT fluid, but in reading this thread, the factory thermostat to the radiator may not even open until ~200F?

Looking at doing the OEM cooler for piece of mind.

Questions for the collective:
1) OEM Denso cooler or an OEM replacement like KYORAD from rockauto? ($90 vs $250-400).
2) When doing the drain/fill - the GXBOB video didn't mention pinning open the thermostat. Worth doing the level set again with that open?
3) Define "a trickle" when setting the AT fluid level. I'm guessing I'm slightly overfilled.

I went with an OEM cooler. I got mine from PartSouq. I paid around $200 shipped. The OEM cooler is tiny and if I had to do again, I'd get something aftermarket which would be cheaper and bigger. The OEM part I'd get though would be the hard line bracket assembly that bolts to the frame to which you can connect the inlet/outlet hoses. I think it's part number 32907-60290.

Pinning open the thermostat is very easy so I don't know why one wouldn't do it. If it were me and I forgot to pin open, I'd probably just make a note to pin it open and do a drain/fill at the next oil change.


At about 13:15 minutes in a "trickle" is shown. That's what I've been using for a "trickle."

 

[thescreensavers]

You 100% need to pin the thermostat open to ensure the whole system fluid level is set correctly per the OEM procedure.

For example if the cooler line is empty and you did not pin the thermostat, then once the stat opens youll have less fluid in the pan.

 

[evolute]

I went with an OEM cooler. I got mine from PartSouq. I paid around $200 shipped. The OEM cooler is tiny and if I had to do again, I'd get something aftermarket which would be cheaper and bigger. The OEM part I'd get though would be the hard line bracket assembly that bolts to the frame to which you can connect the inlet/outlet hoses. I think it's part number 32907-60290.

Pinning open the thermostat is very easy so I don't know why one wouldn't do it. If it were me and I forgot to pin open, I'd probably just make a note to pin it open and do a drain/fill at the next oil change.


At about 13:15 minutes in a "trickle" is shown. That's what I've been using for a "trickle."

I totally agree about the oil cooler hardline that goes through the frame, it gives it a much more finished look. If you look close you can see it in my install pics

 

[Cold Iron]

I have the OEM plumbing for a cooler installed on my 460 as well. This may work well.

I decided to pick up a Hayden 968 with the bypass. The thermostat on the cooler is at 180deg according to Hayden. This will allow me to keep the thermostat pinned open and maintain close to operating temperatures. Most of my driving is short trips and 170-180 seems to be the sweet spot for the A760.

698 I have a hard time keeping it straight as well LOL. Mine is in the garage with the hard mount OEM lines and Mountain Passes mountain bracket.

I agree would really like to see the temps closer to 170-180. On the Tundra forums several are pretty sure the A760 bypass doesn't start to open until ~200 but not sure personally, I haven't seen a point where the temps drop when I've been monitoring it to confirm a set point.

Torn on pinning the T-stat open all year due to cold. On the other hand it may actually help heat it up faster as the engine coolant heats up faster than the ATF. Been 48 years since my heat transfer and fluid flow class in Nuclear Power School but pretty sure heat still flows to cold. Which is why the T-stat is on the tranny to start with but...

14° Ambient air temp with 10 minute run time warming up

Factory T-stat operational it is warming it up but takes time. Even after driving for 20 minutes pan and TC only got to 151\154 I did see it peak to 160° at one point. Engine coolant got to 180° fairly rapidly and seemed to stay there. So pinning it open even the winter may not be a bad thing. Waiting until Spring to install it though to be safe. Temps are going to start dropping to "normal" soon and I don't want to mess with it right now.

I'll wait for you to install yours and you to post the results but I'm sure they will be good

 

[GXFamily]

I got the 698 installed a few days ago. Ambient temp was around 70 degrees and we took a 50 mile trip on the interstate. Transmission temperature was 165-170 the entire way, even with stop and go traffic.

With the OEM cooler I was always at 185-190deg regardless of summer/winter ambient conditions. I'm beginning to wonder if the OEM cooler has a bypass as well as the thermostat has been pinned since the vehicle was new.

Anyways, so far 165-170 degrees is perfect. I'll have to report back during the summer when the ambient temperature gets in the mid-upper 90's and 8000% humidity.

I do wish the fit was a bit better on the mountain pass cooler bracket. I much prefer the Kaon Prado 150 layout where it is more recessed and allows keeping the horns in the OEM location. Other than that, the bracket is high quality.

 

[Rednexus]

I might swap my 678 for a 698. Usually I put a sheet of 1/8" rubber over about 2/3 of the cooler in the winter. Haven't gotten around to that yet and it definitely shifts harsh when it's cold out. It would be nice to not have to do that.

 

[ericm979]

I live about four miles up a very steep twisty road. I had a VW Eurovan whose trans temp would hit 250 or more when I got home. I put a cooler on that. My GX has not had an issue. Today it was 187 at the bottom and 193 when I got home.

Obviously it's not wheeling or towing, but for unladen paved road driving the stock setup seems ok.

 

[evolute]

I live about four miles up a very steep twisty road. I had a VW Eurovan whose trans temp would hit 250 or more when I got home. I put a cooler on that. My GX has not had an issue. Today it was 187 at the bottom and 193 when I got home.

Obviously it's not wheeling or towing, but for unladen paved road driving the stock setup seems ok.

That is good news. What was the outside temperature?

 

[Acrad]

If you can keep in lockup on a grade you can keep temps near coolant but never experienced those staying the same out of lockout.

Also.. if one isn’t using one of the common programs like Torque or OBD Fusion/Link I would make sure you are monitoring coolant as well.

I’ve heard of a few instances of some programs displaying coolant temp erroneously as AT temps.

 

[thescreensavers]

Installed Hyden 678 using Mountain Pass Bracket, used CBM 103 Vibration Isolators to the bracket to give it that OEM Type Kiss
Also installed a 3/8th Magnefine filter prior to the added cooler. I believe these are super important in the GX trans to protect the valve body and the dreaded solenoid codes.

Pinned the thermostat, and put a quart of Idemitsu ATF Type TLS-LV. Got about 1/2 quart back out when I did the level procedure. So new cooler, filter and lines was about ~1/2 a quart of added fluid.

 

[ericm979]

That is good news. What was the outside temperature?

I think it was in the 50s. Results may be different when it's in the '90s. I've had the Scangauge 3 monitoring set up for a couple years and I've yet to see high trans temps but I have not been watching it that closely.

 

[jeremy j]

Installed Hyden 678 using Mountain Pass Bracket, used CBM 103 Vibration Isolators to the bracket to give it that OEM Type Kiss
Also installed a 3/8th Magnefine filter prior to the added cooler. I believe these are super important in the GX trans to protect the valve body and the dreaded solenoid codes.

Pinned the thermostat, and put a quart of Idemitsu ATF Type TLS-LV. Got about 1/2 quart back out when I did the level procedure. So new cooler, filter and lines was about ~1/2 a quart of added fluid.



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Nice clean install. Love the idea of an additional filter. Might have to add that to mine.

 

[thescreensavers]

Small week update, I have had the thermostat pinned all week. So with an outdoor temp of 73f drove about 5 miles of city followed by 20 miles going 80mph down the highway it hit 165f.

A little under where id like it to be so I'll likely pull the pin on the thermostat and see what it does. I know keeping the thermostat pinned keeps the fluid flowing through the filter too.

Figure after the cool season passes here in Florida, it probably will hit 170s-180s as it gets to the 90s again .

 

[rav8]

Small week update, I have had the thermostat pinned all week. So with an outdoor temp of 73f drove about 5 miles of city followed by 20 miles going 80mph down the highway it hit 165f.

A little under where id like it to be so I'll likely pull the pin on the thermostat and see what it does. I know keeping the thermostat pinned keeps the fluid flowing through the filter too.

Figure after the cool season passes here in Florida, it probably will hit 170s-180s as it gets to the 90s again .

Yep. That thermostat is to get the transmission fluid up to operating temp. It bypasses when temps are approaching (or have reached) target fluid temperature. Pinning it is the equavilent of removing your engine coolant thermostat to prevent an overheat. All it will create is longer warm up times for components that had nearly perfect cooling systems.

The best way to provide additional protection is to add a dedicated cooler before the return side of the loop. Many have had good results with this method.