Time to install a transmission cooler

[dieck]

I bought an OBD II wifi dongle for Basecamp and have been watching the transmission temps and pan temps. In day to day driving it stays pretty cool below 170 even on 100deg days. But when I load up my camping trailer which weights between 2000 and 3500 lbs loaded on those same summer days the tranny converter and pan stay in the low 180s with very casual driving and spike up into the 190's on any kind of hill. That's too warm for my taste.

Going to be installing a cooler on it before long.

More to come.

 

[Neauxla]

How do you check your temp?

 

[afalex1]

190 on a hill at highway speed with 3000 pounds really isn't high at all. That is pretty normal for a load of that size with a v6 powered aerodynamic brick 4x4. Lower would be better, but I wouldn't be concerned unless it stayed at 200 or more all the time while towing.

Lower is always better within reason.

 

[Diver Deuce]

I was towing my trailer (2500# empty) and I was hitting 190-205°F. Luckily the trip wasn't very far. I disconnected my aux cooler over the winter since I haven't been towing.

The install is pretty easy though. Have fun.

 

[dieck]

How do you check your temp?

I bought an OBD2 Wireless transmitter and use an app on my iphone to track it.

Works pretty well. The app is not terribly intuitive.

 

[dieck]

Agree on all points. Most post's I've read say tranny life drops off quickly with sustained temps over 170. Even though the transmission will run into the low 200's like it's no big deal. I'm going to try to get a towing temp of around 170 ish after the cooler install.

190 on a hill at highway speed with 3000 pounds really isn't high at all. That is pretty normal for a load of that size with a v6 powered aerodynamic brick 4x4. Lower would be better, but I wouldn't be concerned unless it stayed at 200 or more all the time while towing.

Lower is always better within reason.

 

[Antman]

I run consistently in the 190's (spikes over 200) all summer towing my boat with the A/C on, which is at least 4x/month. This is pan temp measured with the Scangauge- monitoring the temp at the converter is too scary, since I've seen brief spikes over 230 :tape2: lol. Towing the other seasons (I fish all year long) rarely see temps over 180 on hills.

Been doing this since 2011 and I'm not sweating it too much! I figured I'm towing about 1/2 the max capacity and these tranny's are known to be pretty bulletproof so I'll leave the worrying to Toyota on this one. :fishing:

 

[afalex1]

Most vehicles operate around 170 without a load at highway speeds on a hot summer day. After 200 is when transmission life rapidly reduces.

 

[CatskillsRunner]

I run consistently in the 190's (spikes over 200) all summer towing my boat with the A/C on, which is at least 4x/month. This is pan temp measured with the Scangauge- monitoring the temp at the converter is too scary, since I've seen brief spikes over 230 :tape2: lol. Towing the other seasons (I fish all year long) rarely see temps over 180 on hills.

Been doing this since 2011 and I'm not sweating it too much! I figured I'm towing about 1/2 the max capacity and these tranny's are known to be pretty bulletproof so I'll leave the worrying to Toyota on this one. :fishing:

Jeff, how long is your drive one way?

My transmission fluid was really dark when they changed it last month and I'm wondering if towing our trailer to UT and back last summer is to blame. 800 miles a day for 2 1/2 days on the way out, middle of summer, up 70 over the Rockies. The trailer is about 2500 lbs.

I'm wondering if I shouldn't do a cooler because I have some pretty serious wanderlust and always pull that trailer...

 

[mogmanbrad]

I installed a B&M cooler on my 2015 SR5P before I towed either of my trailers, so I have no temp. data. I can say that this is an easy install. Plenty of room to mount the cooler, and easy routing for additional plumbing.

Sorry, no pics.

 

[dieck]

Thanks! I'm going to be installing a hidden winch if the group buy ever goes through and will mount the transmission cooler then while I have the front end taken apart

I installed a B&M cooler on my 2015 SR5P before I towed either of my trailers, so I have no temp. data. I can say that this is an easy install. Plenty of room to mount the cooler, and easy routing for additional plumbing.

Sorry, no pics.

 

[Jetboy]

Since it uses a liquid to oil cooler with engine temp liquid - I'd say 180 would be the normal temp. If not your radiator is heating not cooling your atf. Trying to keep it under 180 would seem like you're fighting the radiator.

 

[dieck]

Does it use an engine to oil cooler? I thought it was a separate section of the radiator that air cooled the tranny fluid.

Since it uses a liquid to oil cooler with engine temp liquid - I'd say 180 would be the normal temp. If not your radiator is heating not cooling your atf. Trying to keep it under 180 would seem like you're fighting the radiator.

 

[Danimal]

Frankly, these temps look good. Below 200 is fantastic, and a testament to the modern transmission and trans cooler. Many of the vehicles I have seen that needed a trans rebuild had seen temps on a regular basis (I'd suspect daily) in excess of 240 or in some cases much higher.

This engine/trans combination is proven, so I'd rather leave it alone than enter some additional leak or failure point in to the hydraulic system (i.e trans cooler).

Dan

 

[Jetboy]

Does it use an engine to oil cooler? I thought it was a separate section of the radiator that air cooled the tranny fluid.

I haven't looked closely but the prior generations of 4runner were engine coolant used to cool trans fluid. The engine and trans use one radiator so I assume its water to oil cooled like most other Toyota products. I could be wrong though.

I think the aux cooler might be why Toyota rates the taco for 7500lbs, but I'm not sure. The 4runner is superior īn every way but wheel base for towing otherwise. Bigger brakes. Stronger frame. Etc.

 

[Jeremy556]

I haven't looked closely but the prior generations of 4runner were engine coolant used to cool trans fluid. The engine and trans use one radiator so I assume its water to oil cooled like most other Toyota products. I could be wrong though.

I think the aux cooler might be why Toyota rates the taco for 7500lbs, but I'm not sure. The 4runner is superior īn every way but wheel base for towing otherwise. Bigger brakes. Stronger frame. Etc.

IIRC, Taco is (or was) rated 6500. Besides wheelbase, other notable differences are Class 4 hitch in the Taco with tow package, vs Class 3 in 4runner, imposes 5K limit right off the bat, Taco has the same trans/gearing but smaller OEM size tires. I think the 4th gen v8 was rated something like 7300-7500.

 

[Antman]

Jeff, how long is your drive one way?

My transmission fluid was really dark when they changed it last month and I'm wondering if towing our trailer to UT and back last summer is to blame. 800 miles a day for 2 1/2 days on the way out, middle of summer, up 70 over the Rockies. The trailer is about 2500 lbs.

I'm wondering if I shouldn't do a cooler because I have some pretty serious wanderlust and always pull that trailer...

Depends on where the fishies are.

Typically 1/2 hr but I make several trips each summer that are over an hour each way- these trips are almost always under high heat conditions.

 

[Jetboy]

IIRC, Taco is (or was) rated 6500. Besides wheelbase, other notable differences are Class 4 hitch in the Taco with tow package, vs Class 3 in 4runner, imposes 5K limit right off the bat, Taco has the same trans/gearing but smaller OEM size tires. I think the 4th gen v8 was rated something like 7300-7500.

That was a typo. 6500.


Does the Tacoma hitch actually use a more robust attachment - to a weaker frame rail? I think the Taco is better suited for towing due to the rear suspension, but I'm not sure the 4runner can't be fixed with some air bags.

More importantly I suppose; isn't the hitch exactly the same as a GX460? It has a tow rating of 6500lbs - which would indicate that it's really somewhere into the class 4 range by SAE standards, but limited by a mfg recommended tow weight?

 

[Neauxla]

Depends on where the fishies are.

Typically 1/2 hr but I make several trips each summer that are over an hour each way- these trips are almost always under high heat conditions.

I drive a lil over an hour each time I go fishing in this hot Louisiana weather. I have a 21' Sea Pro which weighs about 3500 with trailer, engine, gas.

 

[Swarty]

Halfway there

Agree on all points. Most post's I've read say tranny life drops off quickly with sustained temps over 170. Even though the transmission will run into the low 200's like it's no big deal. I'm going to try to get a towing temp of around 170 ish after the cooler install.

The key is sustained temps which is not what you are seeing.
Also 170F is extremely conservative. Sustained averages of 195F still give you over 50K miles for most ATFs in a non sealed transmission. And your temps are only occasional while in a sealed transmission.

The problem with higher temps is oxidation of your transmission fluid. This is both a time and an environmental factor. If you create a low oxygen environment (Like a sealed transmission) oxidation is drastically reduced and the ATF becomes less temp sensitive. The funny thing: everyone is filling their tires with Nitrogen when really they should fill their crankcase and transmission with it. Hot oil is more affected by oxygen than rubber.

Apart from the condition of the ATF the metal parts like bearings and such are not affected until the temps get >400F.