Observed Transmission Temperature while towing (1 Viewer)

LandCruiserPhil

Peter Pan Syndrome
Supporting Vendor
Joined
Mar 10, 2004
Messages
25,082
Location
Scottsdale Arizona
99 Land Cruiser
145K
285/75-16
In-tow #5000 boat
Outside Ambient temp 95°-100° - 0% humidity
Trans fluid 1 week old - Changed regularly
A/C running 100%
36 miles total - one way
~55min driving time

Max trans temp 201°
Min trans temp 143°
Average trans temp(towing) 175°
Max water temp 204°
Average water temp 188°


Max trans temp was reach at 55-MPH at beginning of route on long gradual grade
Used trans braking last 4 miles down steep grade to lake Max trans temp 185°
Leaving lake saw highest water temp but max trans temp was 195°
Cooler trans temp when trans torque converter was locked


90% of braking is done by transmission last 12 miles to lake
Leaving the lake the first ~4Miles is 90% 2ND gear, 50MPH, 3800RPM.
Trans temp would move quickly (up and down) from 190° to 175° during route

On my next trip I will not use OD. Im thinking the higher RPM will net lower trans temp at 55-MPH.

Lake water temp - 75°:D
Boats max speed 47MPH
2 Bald Eagles:cool:
Beer consumption :censor:
Zero bare breast:frown:It was Friday
Profile_0.jpg
2 bald eagles.JPG
 
Last edited:

spressomon

glutton
Moderator
Joined
Jan 9, 2005
Messages
13,404
Location
Northern Nevada
You are correct: 3rd/'02- or 4th/03+ will result in lower tranny temps based on my data at or around 55mph. I can't tell you where the "break even" RPM is but generally I find lower tranny temps with lower gears all things being equal.

On trails where 4H is quite acceptable, from a torque band perspective, I find significantly lower (sometimes 75 degrees lower!) when traveling in 4L instead (typically 20mph or less).

Nice Bald Eagles BTW!
 
Last edited:

Bighead

Veteran of the Psychic Wars
Joined
Nov 4, 2003
Messages
661
Location
Colorado
Just curious since I might be doing some towing with my 100 in the future. With my 4Runner I always had to keep overdrive off. Without getting in the owner's manual I was wondering if I would have to do the same with the 100.
 
Joined
Sep 15, 2004
Messages
2,170
Location
Grand Junction, CO
Phil,
How's the housing market in S'dale now...love that place. Can't wait to get back to Camelback mtn and beat my record of 45 min up and down.

Anytime you're climbing steep grades the O/D should be off. Physically, the O/D is one big clutch inside the TC. Going uphill with weight and not having the O/D off introduces slip into the O/D clutch which cause heat, which causes clutches to start to breakdown. You're pretty safe with temps of 175º.
 

LandCruiserPhil

Peter Pan Syndrome
Supporting Vendor
Joined
Mar 10, 2004
Messages
25,082
Location
Scottsdale Arizona
Phil,
How's the housing market in S'dale now...love that place. Can't wait to get back to Camelback mtn and beat my record of 45 min up and down.

Anytime you're climbing steep grades the O/D should be off. Physically, the O/D is one big clutch inside the TC. Going uphill with weight and not having the O/D off introduces slip into the O/D clutch which cause heat, which causes clutches to start to breakdown. You're pretty safe with temps of 175º.

Scottsdale housing is like every other housing market, a good time to buy.

You Mr. Cruiser Jimmy are in good shape to make CM in 45min. For others the hike is 1.25 miles with an elevation gain of ~1300' and 1.5hrs is considered a good time. At this time of the year the helo and paramedics are there 2-3 times a week because people under estimate the hike in the heat.
 

LandCruiserPhil

Peter Pan Syndrome
Supporting Vendor
Joined
Mar 10, 2004
Messages
25,082
Location
Scottsdale Arizona
I have done this same trip about 10 times since 1st posted and have had a chance to figure out what works for my set up.

Never use OD from start to finish in order to keep temps below 200°

The trans fluid temps likes high RPM better then lugging and MPG does not seem to suffer.

Using the transmission for compression braking is a good thing.

MPG ~9.5 with AC in 100° plus outside temps
 

Users who are viewing this thread

Top Bottom