5th gen 4Runner Mods.

[Telescopist]

Originally Posted by gbaglo

This is what I found in 2007 4Runner manual in regard to WDH.
I don't see anything prohibiting WDH

Very helpful. After burrowing down in the 2019 manual and posted on the inside of the driver's door is the following information. GVWR = 6300#. Vehicle weight capacity - occupants and cargo: 1165#.

[Telescopist]

Originally Posted by Brian B-P

For a 2019, the hitch manufacturer is Toyota. There is no warning against using a WDH, so unless the sticker on the hitch gives only "weight-carrying" limits, I say use a WDH if you decide it is appropriate.

We are in luck.

Here

Here is a real world demonstration of some guy towing a 24 foot trailer with a 4Runner up a relatively steep and long incline. Base on this person's experience he recommends making these changes.
1. A weight distribution hitch with a sway control bar. He argues that one of the limitations of the 4Runner is the short wheel base.
2. A Large Supercooler [14400 BTU Rating] Black Automatic Transmission Oil Cooler.
3. Coil-Rite" Air Bag Helper Springs (Rear)
Note: He keeps saying it is a 20 foot trailer but it's actually a 24 foot trailer.

[Brian B-P]

Originally Posted by Telescopist

He argues that one of the limitations of the 4Runner is the short wheel base.

That's true of SUVs in general; the are relatively short in wheelbase compared to pickup trucks and vans, for the same weight and mechanical specifications.

Originally Posted by Telescopist

A Large Supercooler [14400 BTU Rating] Black Automatic Transmission Oil Cooler.

With that trailer the 4Runner is almost certainly over both the trailer weight rating and the gross vehicle weight rating, as well has pulling a barn door through the air. The transmission is being worked much harder than the same vehicle pulling an Escape 21' would be, and so it might need transmission cooling that might not be needed with the Escape.

Originally Posted by Telescopist

Note: He keeps saying it is a 20 foot trailer but it's actually a 24 foot trailer.

He says it's a 20-foot trailer because the body is about 20 feet long, and the model name reflects that. While Escape and most other moulded fiberglass travel trailer manufacturers (as well as Airstream) use overall length (bumper to ball) to designate their models, the rest of the RV industry (as well as cargo trailer manufacturers) generally uses body length.

[Telescopist]

What I thought was encouraging is that he is pulling an aerodynamic disaster that has a dry weight of 4345# in 'S3' at 50mph. The rpm reading looked decent. It is an encouraging sign To some degree lessens my worries about towing a 21 that has a dry weight of 3500#. I am going to install an auxiliary transmission cooler. And while I'm at it those air bag helpers.

[jeffrow]

If its of any help, I pull a 21' with a 4th gen 4wd v8 4Runner. Currently have the standard aux tranny cooler and I installed airbags in the rear. I find the power, handling and braking to be acceptable. I do stress out about tranny temp. I am monitoring it with a scanguage and am unsatisfied with the temp on long uphill freeway grades and slower uphill mountain roads. 125 to 140 degree not uncommon when torque converter is unlocked.

[Telescopist]

Originally Posted by jeffrow

If its of any help, I pull a 21' with a 4th gen 4wd v8 4Runner. Currently have the standard aux tranny cooler and I installed airbags in the rear. I find the power, handling and braking to be acceptable. I do stress out about tranny temp. I am monitoring it with a scanguage and am unsatisfied with the temp on long uphill freeway grades and slower uphill mountain roads. 125 to 140 degree not uncommon when torque converter is unlocked.

I think you are just fine then. 'Normal' operating fluid temperature for the transmission is around 175 degrees from what I have read. The prudent thing probably would be to replace the transmission fluid at more frequent intervals when towing in hilly terrain. Would you agree with that?

I think installing a ScanGauge might be in my future plans. Although by the time I get done installing gauges - brake controller, tire pressure monitoring system for the trailer, and a few other odds and end, I'll be too busy to enjoy the scenery.

[Brian B-P]

Originally Posted by Telescopist

I think installing a ScanGauge might be in my future plans. Although by the time I get done installing gauges - brake controller, tire pressure monitoring system for the trailer, and a few other odds and end, I'll be too busy to enjoy the scenery.

Since you're getting the transmission temperature from the CAN bus anyway, you could just let a logger record values, and have a look after stopping for the day. You would see if there is any long-term concern, without distraction while driving.

[jeffrow]

Originally Posted by Telescopist

I think you are just fine then. 'Normal' operating fluid temperature for the transmission is around 175 degrees from what I have read. The prudent thing probably would be to replace the transmission fluid at more frequent intervals when towing in hilly terrain. Would you agree with that?

I think installing a ScanGauge might be in my future plans. Although by the time I get done installing gauges - brake controller, tire pressure monitoring system for the trailer, and a few other odds and end, I'll be too busy to enjoy the scenery.

I'm sorry, I misspoke. The temp was 225 to 240. Temp goes up very quickly when trans unlocks in 4th where I always tow. The guy in your video is scary naive bragging about 50mph in 3rd being good when he has no idea of the trans temp. My unknown is that there are supposed to be 2 tranny temp measurement points in the Toyota 5sp auto. One at or near the return in the pan, the other immediately after the torque converter. Only one of the pids I found for the scanguage worked for me when I set it up. I speculate that the point I am measuring is at the torque converter because the temp jumps immediately when the transmission unlocks and drops fairly quickly when it re-locks.

[Dave Walter]

Originally Posted by jeffrow

...My unknown is that there are supposed to be 2 tranny temp measurement points in the Toyota 5sp auto. One at or near the return in the pan, the other immediately after the torque converter. Only one of the pids I found for the scanguage worked for me when I set it up. I speculate that the point I am measuring is at the torque converter because the temp jumps immediately when the transmission unlocks and drops fairly quickly when it re-locks.

I was able to access both transmission fluid temperature sensors in my FJ using the Scangage. The temperature behaviour that you describe (one temp fairly constant while other rises and falls more rapidly) is very similar to what I have experienced.

[BRietkerk]

The 4 Runner has the 7 pin connector under the left side of the bumper. ETI should be reminded that this requires a longer made up 7 pin cable than they install as standard. When we started towing with our 2016 limited 4 Runner I had to buy a longer cable to replace the original. I did not want to add a junction box or a splice.
Cables are made up in two standard lengths. I purchased the long version at a local RV dealer.
You may want to advise ETI the measurement from 7 pin receptacle to ball on your TV.

[cpaharley2008]

otherwise you may need something here https://www.etrailer.com/s.aspx?qry=...url=-pg-Wiring

[Telescopist]

Originally Posted by BRietkerk

The 4 Runner has the 7 pin connector under the left side of the bumper. ETI should be reminded that this requires a longer made up 7 pin cable than they install as standard. When we started towing with our 2016 limited 4 Runner I had to buy a longer cable to replace the original. I did not want to add a junction box or a splice.
Cables are made up in two standard lengths. I purchased the long version at a local RV dealer.
You may want to advise ETI the measurement from 7 pin receptacle to ball on your TV.

Thanks for sharing that tidbit. I just got done emailing Escape about this.

[cpaharley2008]

Also note, the owner with the short cable has a 2012 model, ETI may now provide a longer standard cable.

[jeffrow]

Originally Posted by Dave Walter

I was able to access both transmission fluid temperature sensors in my FJ using the Scangage. The temperature behaviour that you describe (one temp fairly constant while other rises and falls more rapidly) is very similar to what I have experienced.

My 4Runner is a 2007..... maybe thats the difference CAN wise.
Do you recall how hot your transmission has run?

[jeffrow]

Originally Posted by cpaharley2008

Also note, the owner with the short cable has a 2012 model, ETI may now provide a longer standard cable.

Probably is longer now, mine is plenty long.

[Dave Walter]

Originally Posted by jeffrow

My 4Runner is a 2007..... maybe thats the difference CAN wise.
Do you recall how hot your transmission has run?

On the FJCruisers forum, I found codes to monitor two transmission sensors in the FJ, and programmed the Scan Gauge accordingly with a TF1 and TF2 readout.

The auto transmission in my FJ has gears designated D, 4, 3, 2 and 1, and Toyota recommends keeping in 4th while towing. I found that non-towing (driving in D) in relatively flat terrain in summer type weather, the transmission fluid temperatures after continuous driving were typically in the range of about 165 to 180°F. While towing (in 4th gear) on relatively flat terrain in summer, the transmission temps typically stayed between about 175 to 200°F. I did notice really early that the transmission temperatures are about 10-20° hotter if I forgot to use 4th gear while towing and left the transmission in D.

Of the two temperature sensors on my transmission, one of them is much more sensitive to temp changes than the other, and tends to climb rapidly when the transmission is working hard. From posts by others on the FJ forum, it seems that this sensor may be located right at the outlet from the torque converter.

My highest recorded transmission fluid temperatures occurred while towing on a couple of very high mountain passes in Utah. While climbing up these steep mountain roads to near 9000 ft elevation, the transmission fluid temperatures would climb to the 220-230°F range. However, on one section of one pass in Utah, the TF temperature rose to nearly 250°F, which was beginning to worry me. Good news was that the temperatures always stayed high for only a few moments and dropped off very quickly when the transmission load was reduced.

The Scan Gauge has been a very useful tool in monitoring the TF temperatures and towing performance, and has helped me to understand much better how my rig is operating. Given that 99% of my towing has not involved going up-down high mountain passes in extremely hot weather, I did not see a need to buy a secondary TF cooler for the FJ, and I think that I will continue as things are now set up.

[Telescopist]

Originally Posted by Dave Walter

On the FJCruisers forum, I found codes to monitor two transmission sensors in the FJ, and programmed the Scan Gauge accordingly with a TF1 and TF2 readout.

The auto transmission in my FJ has gears designated D, 4, 3, 2 and 1, and Toyota recommends keeping in 4th while towing. I found that non-towing (driving in D) in relatively flat terrain in summer type weather, the transmission fluid temperatures after continuous driving were typically in the range of about 165 to 180°F. While towing (in 4th gear) on relatively flat terrain in summer, the transmission temps typically stayed between about 175 to 200°F. I did notice really early that the transmission temperatures are about 10-20° hotter if I forgot to use 4th gear while towing and left the transmission in D.

Of the two temperature sensors on my transmission, one of them is much more sensitive to temp changes than the other, and tends to climb rapidly when the transmission is working hard. From posts by others on the FJ forum, it seems that this sensor may be located right at the outlet from the torque converter.

My highest recorded transmission fluid temperatures occurred while towing on a couple of very high mountain passes in Utah. While climbing up these steep mountain roads to near 9000 ft elevation, the transmission fluid temperatures would climb to the 220-230°F range. However, on one section of one pass in Utah, the TF temperature rose to nearly 250°F, which was beginning to worry me. Good news was that the temperatures always stayed high for only a few moments and dropped off very quickly when the transmission load was reduced.

The Scan Gauge has been a very useful tool in monitoring the TF temperatures and towing performance, and has helped me to understand much better how my rig is operating. Given that 99% of my towing has not involved going up-down high mountain passes in extremely hot weather, I did not see a need to buy a secondary TF cooler for the FJ, and I think that I will continue as things are now set up.

Very useful information and I appreciate it. Your conclusion that an auxiliary cooler is not warranted is interesting. How it will effect my decision about whether to install one or not is still in the air...

I just had a fairly lengthy (15 minutes) conversation with the head of the service department at my local Toyota dealership. Basically he said that the warranty is not voided by adding an auxiliary cooler UNLESS it is found that the cooler was the cause of the failure. What they would do is some sort of forensic (my word) examination of the transmission, the cooler, and anything in between. Then they would contact the Toyota Technical Experience Center and consult with them. The TTEC has the final word of course.

He did say that they rarely run into situations where the transmissions on these vehicles actually fail. He seemed to be saying that the transmission is pretty reliable and robust.

[jeffrow]

Thank you for the detailed response.

This duplicates both my driving habits and temperature swings. I hit low 240 ish on a long 6% grade with a 25 mph headwind a few weeks ago. Thats probably my high water mark since getting the scanguage. I suspect pulling my previous Casita I at least duplicated that going in and out of Death Valley in 90 degree weather though.

I have read some scare stories about trans temperature that described some scary stuff at 240-260 regarding damage to fluid and transmissions. This may be old school out of date info afaik given the synthetic modern fluids.

I'm considering installing an additional cooler with a thermostatically controlled fan so I don't stress about this too much.

Thanks again.

[jeffrow]

Originally Posted by Telescopist

Very useful information and I appreciate it. Your conclusion that an auxiliary cooler is not warranted is interesting. How it will effect my decision about whether to install one or not is still in the air...

I just had a fairly lengthy (15 minutes) conversation with the head of the service department at my local Toyota dealership. Basically he said that the warranty is not voided by adding an auxiliary cooler UNLESS it is found that the cooler was the cause of the failure. What they would do is some sort of forensic (my word) examination of the transmission, the cooler, and anything in between. Then they would contact the Toyota Technical Experience Center and consult with them. The TTEC has the final word of course.

He did say that they rarely run into situations where the transmissions on these vehicles actually fail. He seemed to be saying that the transmission is pretty reliable and robust.

If you don't have an external cooler stock, I would highly recommend one. Or at least have some way to monitor the trans temp.

[Telescopist]

Originally Posted by jeffrow

If you don't have an external cooler stock, I would highly recommend one. Or at least have some way to monitor the trans temp.

Understood. I agree. Dave information about the Scan Gauge and what he reported is helpful information. I may have bit off more than I can chew by going with the 21 instead of the 19. But then this guy who lives near me in York talked me into getting the 21.

I'm looking at this one from e-Trailer.