Transmission Temp

[gordonp]

Some good thoughts and suggestions in this Thread...

Sure, gear down when you encounter a hill (even when not towing, I'd say, and if it's a San Fransisco kinda steep hill!).

My personal "warning light" when using Torque Pro: if the transmission temp crosses the water temp. This is very conservative (occurs around 210F in my experience), the transmission fluid can certainly tolerate more. I did see this crossover in temperature *ONCE*, then I installed a large (22,000GVW) cooler. Now, it never comes close, even with full load (4500lb trailer and all the "stuff").

BTW - the Toyota WS (World) ATF is basically Dexron 4 - which is basically Dexron III but in synthetic. Probably a reasonable choice in 2003 when these transmissions were developed for the one-ton T100, but pretty much anything "modern" will have improved specs *across the board*. So, IMHO feel free to top up or flush with Dexron VI from your local parts-store

 

[Jetboy]

FWIW - very old thread, but still relevant - GM testing for Dextron VI standard for oxidization (how it handles heat) is 450 hours continuous running in a 4L60E transmission under load at a test facility at 325* F. Allison uses the same test for its fluid spec for 600 hours. If toyota WS is anything like that - 250-270 degree temps are a non-issue even sustained for a few hours periodically. According to Shell - as a general rule oil life is halved by every 10 degree increase in operating temp. If that applies to Toyota WS and it's as good as Dextron VI and is still serviceable after 450 hours at 325F, it would last about 15,000 hours at 270, or 60,000 hours at 250 degrees. If you translate that to 50 miles per hour that's 750,000 miles at 270 degree continuous use temp or 3,000,000 miles at 250F operating temp.

This chart has been around for longer than I've been alive.

There was a time when it probably was accurate, but it has little or no relevance with modern transmission fluids. If that chart were accurate, you'd expect fluid to break down very rapidly at 300* and you certainly wouldn't see fluid remaining acceptable at 600 hours over 300*F.

 

[RRosco]

A lot of great info on this thread beyond just servicing. thanks!

 

[T4RFlorida]

Hi guys. Know this is an old thread but you all seem to have the technical knowledge I’m looking for.

Here’s the short, had my transmission fluid changed by my shop at 40k and my tech (who is a master Nissan tech I’ve known for 10 years) told me the fuild was the nastiest fluid he’s even seen out of any truck with 40k miles. Due to the condition of the fuild I went overkill (ask usual) and added a secondary Mishimoto transmission cooler and a CSF racing radiator.

For offroad use I normally race my friends which ATVs and dirt bikes offroad, nothing timed but figure 65-85MPH in the sand.

My concern and question is based on the daily driver use. The transmission temps only rise to about 130ish to 140’when I’ve been driving for 20+ minutes. Off road I’ll get the transmission to 180-190.

Does the low transmission temps pose any issues?

I welcome any technical feedback

 

[RRosco]

Hi guys. Know this is an old thread but you all seem to have the technical knowledge I’m looking for.

Here’s the short, had my transmission fluid changed by my shop at 40k and my tech (who is a master Nissan tech I’ve known for 10 years) told me the fuild was the nastiest fluid he’s even seen out of any truck with 40k miles. Due to the condition of the fuild I went overkill (ask usual) and added a secondary Mishimoto transmission cooler and a CSF racing radiator.

For offroad use I normally race my friends which ATVs and dirt bikes offroad, nothing timed but figure 65-85MPH in the sand.

My concern and question is based on the daily driver use. The transmission temps only rise to about 130ish to 140’when I’ve been driving for 20+ minutes. Off road I’ll get the transmission to 180-190.

Does the low transmission temps pose any issues?

I welcome any technical feedback

I usually go overboard with trans cooling as well. I monitor mine with the scangauge II in my 4Runner and Lexus ES350. I also use Mishimoto as well as Hayden. My 2 GMC trucks have factory gauges.

I see no issue at all with your trans temps, especially where you are located. When you are Off Road your temps are hot enough to never worry about any condensation issues.

I even added an external Hayden cooler to my ES350 due to temps staying in the 190 - 210 range during the summer here in GA. Now it stays in the 160 - 170 range.

 

[Hungryhawk]

If you can get under your 4runner, why not remove fill plug and use a suction syringe (be careful not to let anything drop into tranny thru the fill plug) to pull out several ounces of ATF. Examine its color and smell. If brown and burnt smell and it does not seem like new ATF I would drain & refill.
You can always push the syringe of old fluid back into the fill plug -close it up and take it to your prefered service shop.