- Joined
- Oct 22, 2002
- Threads
- 169
- Messages
- 5,337
- Location
- Durango, Colorado
- Website
- www.durangomagazine.com
Has anyone researched a published spec from Toyota for normal trans operating temps for the 250?
Transmission temps on LC 250 (2 Viewers)
- Thread starter LCQ
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Similar concerns for towing our 2,800lbs teardrop in mountains. Will be curious to see what additional cooling options are available.
Are you thinking 230 is too high?
The last Ram truck I drove that has the readout on the dash was running right in that range in just normal driving. I think that's probably not far off of the target temp value. This was covered in another thread - but the standard baseline fluid test for GM Dextron IV is a transmission operating under load on a dyno steady state at 350*F fluid temp for 450 hours and remaining with acceptable oxidization levels. The Allison transmission TES-295 and TES-353 benchmark testing for the certification is 600 hours at 350*F in an operating transmission under load.
I don't know how Toyota fluids compare to Dextron IV or the TES standards, but if its similar - 230 is a non-issue. Even 270 is a non-issue. Stable temperatures close to the designed ideal temp will always be preferable. But the fluid life of modern transmission fluids wouldn't be materially shortened by running at 230-250 regularly and up to 270's for short periods. It's probably more of an issue for things like plastics and seals than it is for the actual fluid. Unfortunately Toyota doesn't give us much information on what WS fluid is or what the characteristics are.
Just some food for thought on weather it's really worth all the effort to add an auxiliary cooler. I personally did add one on my 5th gen 4Runner because I towed a lot with 34" tires, often north of 5,000lbs - but it was probably not needed. I don't think I ever saw it go beyond about 230 without it. What's funny is that my RX350 has a stand alone trans cooler with a dedicated air flow path. On a vehicle that didn't even come with a tow hitch. Not sure why it has one or would ever need it. But it's there. I'm sure Toyota has a reasoning for doing thing the way it does them, but it's not always clear to me.
Last edited:
I guess I was just worried about it being that hot on a short trip in relatively flat Pennsylvania, Towing cross country up mountain passes is what worries me, but maybe you are correct and that isn't hot at all.
Toyota WS is known - anecdotally - as a relatively poor-quality fluid that is 1) a conventional and not a synthetic and 2) does not handle heat very well. The somewhat concerning failure rate of 6-speeds in the GX460 - which may think are due to the combination of no external trans cooler, the WS fluid, and Toyota's marketing of it as a "lifetime" fluid - should be a red flag for any LC250 owner that Toyota hasn't really learned any lessons in terms of trans cooling.
For my 120-platform rig, I've added a larger external cooler (Hayden 678), installed a Nomad valve body and lockup switch, and changed to synthetic Valvoline MaxLIfe AFT. My trans usually runs 170-180F and has never gotten above 220F after those mods, and that was in some rather extreme conditions.
If I were to buy a LC250 (or a GX460 for that matter) I would figure out a way to mount a Hayden 678 or similarly-sized auxiliary cooler. I can't imagine a replacement 8-speed trans with hybrid integration to be cheap to replace. The cooler itself is only $60 - same price as 5 quarts of Toyota WS!
It's really hard to know with the lack of information from Toyota about the fluids and engineering of the transmission. ATF is one of the most complex fluids used in vehicles because it has many functions that include lubricating bearings, pressure transfer to move mechanical parts, not overly lubricating fiction plates. There's a ton of complex chemistry that goes into the package of additive to do all of those things and also prevent the base oil from breaking down under stress and heat. 230 might be too hot for WS fluid, but it also might have no measurable effect on it. Unless Toyota will tell us or someone does the same type of benchmark testing like Intertek does for the GM and Allison fluids, I'm not sure we'll ever know. Toyota is a black box. It even lists different viscosities for Toyota WS and Aisin WS fluids. Are they different? Not sure.
All I can really say is that I would be pretty comfortable with 230. I would not feel great about 250+, but that's not really based on any science because I don't know what the properties of Toyota WS are. In my Tundra I see up to 230 at times and it has an aux cooler. But it doesn't seem to matter if I'm towing 4k lbs or 10k lbs. It doesn't change much on the trans temps. I tow about 50-60% of my miles and I did a first trans drain an refill at 95K miles. Fluid looked great, smelled like fresh crayons. I may not touch it again. Not sure.
It would be great to know even what Toyota's target oil temp is for the transmission. That would give you a lot more information to make a decision on whether it is worth the cost and effort to add a second cooler.
Last edited:
It's not totally clear to me if WS is even a single formula. Toyota WS and Aisin WS are different viscosities for example. Are they the same? I have no idea.
Maxlife is also intersting in that it claims to be things that are impossible - for example being both T4 and WS which are different viscosities. It also claims to be Honda DW-1 compatible but it's not really close at all chemically. Basically Valvoline says it works in almost every automatic transmission regardless of OEM fluid type. If the oil type, viscosity, or additive package matters, that can't be true. If none of those matter and basically any ATF can work - it could be true. GM puts the same transmission in a Malibu that Toyota uses in a Camry, GM puts Dextron IV and Toyota puts WS in and they both work. Maybe it really is all the same and it doesn't matter?
Depends if 230 is pan or torque converter. On my 200 I see a stable temp of about 217F when towing, pan and torque converter. If the torque converter unlocks it’ll easily run 230-240 and I don’t see it as a big deal if the pan temp is lower and stable because this is hot fluid coming out of the transmission but is being cooled ok. I don’t start to worry about temps until the pan starts getting up to 250F, which I’ve only seen on the highway on Vail pass with a 6000# trailer in tow in sunmer
I can't speak for non-Toyotas, but it has an excellent track record in WS-recommended transmissions. I've been running it for over 50K now and did a full replacement with a pan drop about 6K ago. The fluid holds up quite well and is widely available at a reasonable price, neither of which is the case with WS.
You need a WAT lockup switch
. I lock my TCC in 3rd and 2nd gear when towing around here or on long passes out west. The pan temps will start dropping immediately and stabilize back to 170-180F within a few minutes of locking. I'm also theorizing that this keeps engine coolant temps lower as less trans heat is making it to the radiator.217 is hotter than I'd like to personally run. If that was my rig I'd splice in a bigger cooler or change the fluid every 30K.
Last edited:
Does any one know if the LX 600 or LC 300 has a dedicated trans cooler?
I know they ditched it on the Tundra starting in 2019 and they haven’t added it back yet.
I know they ditched it on the Tundra starting in 2019 and they haven’t added it back yet.
bjowett
Supporting Vendor
The LX/300 Series, as well as the 22+ Tundra have the same system/style trans coolers as the 250. There are similar threads about high temperature on Tundra forums.
Add an external oil to air ATF cooler if you want the trans to live long happy life.
WS is a good Group III fluid, but high heat will deteriorate it quickly. Best thread on thin ATF fluids for Toyota, drop it in your favorite translator. Сводная таблица жидкостей АКПП аналогов Toyota Type WS - https://www.oil-club.ru/forum/topic/23872-svodnaja-tablica-zhidkostej-akpp-analogov-toyota-type-ws/
Add an external oil to air ATF cooler if you want the trans to live long happy life.
WS is a good Group III fluid, but high heat will deteriorate it quickly. Best thread on thin ATF fluids for Toyota, drop it in your favorite translator. Сводная таблица жидкостей АКПП аналогов Toyota Type WS - https://www.oil-club.ru/forum/topic/23872-svodnaja-tablica-zhidkostej-akpp-analogov-toyota-type-ws/
Agreed, with the tow rating of only 6K pounds, a full tank of fuel, 2 adults, and a bit of gear inside the rig would probably have maxed out on payload with a lot of weight on the rear axle. I hadn't realized before this but it's interesting that the 250 is rated to tow 500 pounds less than the GX460/GX470 are.
The 2.4 turbo has more power and torque at low-mid rpms than any of Toyotas v8s. Seems like it should be fine pulling 5k lbs. My 5.7 isn't stressed at all with that size trailer. There's times when it would probably run short on hp up long passes. Chassis is similar to the GX that pulls a lot more. Brakes are big. On paper it seems well equipped to pull 5k regularly.
I don't put any value on mfg payload, some people do. I simply don't believe that a Corolla cross has more safe load carrying ability than a tundra.
112 wb is certainly too short for great bumper towing, but it could work.
I don't put any value on mfg payload, some people do. I simply don't believe that a Corolla cross has more safe load carrying ability than a tundra.
112 wb is certainly too short for great bumper towing, but it could work.
There are liability and legal concern exceeding the payload and/or tow rating on any rig. Which is partially why I stick to about 2/3 of max rating.
Regarding Toyota's calcs, it could also be a suspension/shock thing, or a limit in the rear axle rating associated with the added weight of the rear battery. Or, perhaps like the 5th gen 4Runner and 460 tow rating discrepancy, it could be related to the hitch design itself, or the integration of the rear crossmember/hitch around the battery.
I change the fluid every 30k. Truck is at 162k now. I bought it at 49k, probably close to half the mileage is towing.You need a WAT lockup switch
217 is hotter than I'd like to personally run. If that was my rig I'd splice in a bigger cooler or change the fluid every 30K.
View attachment 3752871
Yes I should probably add a tertiary cooler. A few have done it but it doesn’t seem to matter much on the 200 except on those mountain passes.
I’ve considered reprogramming the ECU to allow me to lock the TC. I think VFTuners or one of the other programming options supports it now.
Fwiw the LC runs at 196F stock setup at highway speed in my experience, same as the coolant temp.
- Thread starter
- #38
Dealer update:
Got some fun questions when I dropped it off. "Was the e-brake on?" "Did you have it in four wheel drive?" Anyway, they think it must have been a fluke/glitch since the ECU didn't store any codes that they could see and it appears to be operating normally. The advisor went on to explain how the ECU stores all sorts of info and they probably would have been able to see it if it was running too hot. Not sure if this is true or not on Toyota's, but it would be nice to see a log of all the transmission events. So I'm pounding sand for now.
Following this closely as I live in Tucson and am planning on towing our Airstream Basecamp (3500# max) up to Ten Sleep Wyoming and into the Bighorn mountains (~9,500') with the wife's LC 250.
I see that these vehicles do have a transmission oil cooler, but given that it is a liquid to liquid cooler using the antifreeze which will be 180-190, I would much prefer an auxiliary cooler since the air is much cooler than the engine coolant.
If anyone has installed an auxiliary transmission cooler, please reach out to me with the details.
I see that these vehicles do have a transmission oil cooler, but given that it is a liquid to liquid cooler using the antifreeze which will be 180-190, I would much prefer an auxiliary cooler since the air is much cooler than the engine coolant.
If anyone has installed an auxiliary transmission cooler, please reach out to me with the details.
The 200 has both a liquid and air cooled radiator. But @TeCKis300 has a thread that shows how he installed a third cooler (second air cooled radiator) if you search around the forum a bit
