User Tag List

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-22-2019, 01:43 PM #1
Bluesky 07's Avatar
Bluesky 07 Bluesky 07 is offline
Senior Member
 
Join Date: Sep 2014
Location: Cherokee Co., GA
Posts: 2,754
Real Name: Russell (OB #9908)
Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future
Bluesky 07 Bluesky 07 is offline
Senior Member
Bluesky 07's Avatar
 
Join Date: Sep 2014
Location: Cherokee Co., GA
Posts: 2,754
Real Name: Russell (OB #9908)
Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future Bluesky 07 has a brilliant future
Transmission Oil Temp Observations & Questions

I had OBD Fusion connected for the recent Kentucky Toyota Trail Ride as I wanted to get a feel for these readings on and off road. Here are screenshots from various times and the overall takeaway is that Toyota did a fine job designing a system that keeps everything relatively cool.

Trail driving (except the gravel sections) was done in L, 2, or 3 as appropriate. These are in time stamp order. You can see altitude changes and our coordinates if you wish to map our exact position, and the intake temp shows that it was a hot one yesterday. There were rocks, streams, climbs, steep crawl descents, and mud. For example, this 5th Gen needed some help and reached the top minus some lower front end body parts and with a bent step rail.



Not saying these were black diamond trails but it sure wasn't gravel cruising either.

This is at 0915 in the group lineup before leaving Callie's Campground for the trails:



On the trails (numbers are times):

1108


1227


1442


1520


1545



You get the idea - the tranny oil temps stay pretty reasonable on the trail.

Here's the odd part: I've had this hooked up in the past without taking screenshots and only saw the ATF temp get close to 200F a couple of times. So I was surprised when the reading at the TC rose to about 225 on the way to the trails. We were still on pavement and climbing a moderate incline. Gear selection was the usual 4D.

I didn't get a screenshot then but stopped by Cumberland Gap National Park on the way home and noticed the same thing while driving up to Pinnacle Overlook. Here's a screenshot from the top:



(Ignore the green/yellow/red arcs as I have redone them since learning last night that the A/T OIL TEMP dash light doesn't come on until 275F per the FSM.)

What was very interesting is that the temp began dropping whenever I changed from 4D to using whatever gear (2/3/4) seemed best for the section I was on. (I drove a stick for 17 years so I have a good sense of what gears to use.) I only know the basics of how transmissions work so I watched a video on torque converters to try and understand why that happened but still have a question:

Does driving in a specific gear bypass or disengage the torque converter? That's the only reason I can think of for the oil temp to stabilize then decrease when I shifted directly.

Also, on a semi-related note:

If there's a PID for oil temps in the transfer case and/or diffs, I missed it. Anyone know if there are sensors there and/or how to do an associated PID?

Thanks for any insight.

Last edited by Bluesky 07; 07-22-2019 at 01:47 PM.
Bluesky 07 is offline   Reply With QuoteReply With Quote
Old 07-22-2019, 05:19 PM #2
AuSeeker AuSeeker is offline
Senior Member
 
Join Date: Nov 2016
Location: South Carolina
Posts: 4,618
Real Name: Skip
AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future
AuSeeker AuSeeker is offline
Senior Member
 
Join Date: Nov 2016
Location: South Carolina
Posts: 4,618
Real Name: Skip
AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future AuSeeker has a brilliant future
First and foremost is the torque converter never stops working unless it's broken, when it spins it becomes, among it's other functions of transferring the engine power to the transmission, the primary/front pump to help produce the hydraulic pressure in the transmission.

I know that the torque converter will get hotter until it locks out when the transmission and engine speeds reach around the same speeds, this is because the converter is working much harder to transfer power from the engine to the transmission, once the converter locks out it is more or less a direct connection between the engine and transmission and not relying on hydraulic pressure and friction to transfer the power, so going up an incline in the highest gear will usually stop the lock out from happening.
__________________
2004 Limited V8
AuSeeker is offline   Reply With QuoteReply With Quote
Old 07-23-2019, 03:51 PM #3
randy88fj62's Avatar
randy88fj62 randy88fj62 is offline
Member
 
Join Date: Jul 2019
Location: santa clarita
Posts: 396
randy88fj62 has a spectacular aura about randy88fj62 has a spectacular aura about randy88fj62 has a spectacular aura about
randy88fj62 randy88fj62 is offline
Member
randy88fj62's Avatar
 
Join Date: Jul 2019
Location: santa clarita
Posts: 396
randy88fj62 has a spectacular aura about randy88fj62 has a spectacular aura about randy88fj62 has a spectacular aura about
Normal operating transmission temps should be around 190°F. It's not uncommon to see spikes up to 230°F. Past that and I would be worried.

The torque converter needs to be locked up in order for temps to be stable. When the torque converter is working hard and not locked it will produce a lot of heat. It's your job to navigate your gears to achieve this.

1. If you're driving slow and working hard, shift your tcase in to low gears.

2. Synthetic transmission fluids will give you around a 20°F lower operating temperature. Invest in a reputable brand of your choice.

3. Larger tires over work the stock transmission cooler. If you are running 33's or larger then you are beyond Toyota's transmission cooler design and you may want to install a larger one.

4. Tire weight: BFG KM3's for instance are heavy beasts compared to Goodyear Duratracs.

I haven't looked at the specs of your truck and what you have on it so the above is the basics for keeping your trans in good shape.
randy88fj62 is offline   Reply With QuoteReply With Quote
Reply

Tags
gear , oil , temp , times , trails

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Intake air temp observations ebg18t 4th Gen T4Rs 5 09-11-2019 06:51 PM
Observations and questions mavrick1903 4th Gen T4Rs 6 09-05-2014 04:30 PM
Transmission Temps: Observations and Revelation OrdnanceMarine General Discussions 58 06-12-2013 07:24 PM
Ride Quality Questions/ Observations. fmixman 5th gen T4Rs 31 03-02-2011 08:20 PM
New 4Runner Observations and Questions Kerouac 4th Gen T4Rs 14 06-06-2007 05:47 PM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -4. The time now is 11:32 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
***This site is an unofficial Toyota site, and is not officially endorsed, supported, authorized by or affiliated with Toyota. All company, product, or service names references in this web site are used for identification purposes only and may be trademarks of their respective owners. The Toyota name, marks, designs and logos, as well as Toyota model names, are registered trademarks of Toyota Motor Corporation***Ad Management plugin by RedTyger
 
Copyright © 2020