My transmission temperature raises when I drive a trail in 4HI slower than ~15mph. I have to use manual transmission mode or 4LO. In this case temperature stays in the middle of the gauge. To me this feels weird.
Transmission Overheating - anyone else?
- Thread starter fuzznuts
- Start date
My transmission temperature raises when I drive a trail in 4HI slower than ~15mph. I have to use manual transmission mode or 4LO. In this case temperature stays in the middle of the gauge. To me this feels weird.
I have around 8400 miles on a 1958 model and it has 3 oil changes on it never a overheating issue
This is because the transmission is anticipating a gear change. The anticipation cause clutch and torque converter slippage which increases tranny temperature.
The 4lo just keeps the LC going slower with higher RPM. The LC isn’t anticipating as many gear changes which in turn keeps the tranny cooler.
Today we drove a fairly steep trail up to Cerro Gordo, about 4600 ft in a little under 8 miles. Lots of washboard and twists, but mostly just steep. In 4 Low the transmission temp gauge stayed right in the middle of the range. In 4 High it would trend up a little but never got to 3/4th of the scale. I mostly used 4 Low. On the way down I used mostly 4 High and hill descent control, nothing that had a gauge got very hot. I wondered about the brakes...
When its in 4LO, and you're driving parts of the trail that don't need it - do you leave it in 4LO? The RPMs shoot to the higher end, seems like that would overheat things no?
Anyplace that felt like I should be going over 15 MPH I used 4 High, but that wasn’t very much of the road. Nothing appeared to be overheating in 4 Low.
Hello y'all. New to the Toyota World. Been offorading on Jeeps for a while and it was always a normal thing to either run in 4hi or even 2wd through must easy to moderate trails, and never had a tranny temp issue. With that said, just exchanged the Jeep for a LC250 and to my surprise, the fisrt run to an easy trail the tranny overheated in regular drive. Did an overlanding Trip as well and evrytime a constant uphil (maybe 9 to 15 degree incline) the tranny will start sgooting up. So it seems I am having the same issue. Though if I change to manual and just shift between 1st and 2nd it does ok. Have not contacted the dealership yet. Is this normal for Toyotas? Please help as I am starting to now doubt the whole reason I changed to Toyota.
Jeep had a JeepCares in all Forums that will respond to issues like this, does Toyota have anything similar?
Jeep had a JeepCares in all Forums that will respond to issues like this, does Toyota have anything similar?
- Moderator
- #109
Welcome to the Jungle!
Welcome to the asylum.
Most likely torque convertor is slipping, which causes overheating. I believe there is a mechanical lockup in the TC that engages to prevent this, but it doesn't engage because the truck shift to way high of a gear and cannot lock TC due to speed difference between two ends (aka slip).Manually keep it in 1 or 2, or use 4L and it will lock, and wont overheat.
No Toyota does not respond to forum posts.
Thank you for your response. So, is this normal for this vehicles?, or is it a defect? It only has 750 miles. Non of my offroad vehicles ever did anything like this.
Has anyone confirmed if tow haul mode locks the TC?
I THINK that tow haul mode just changes the shifting chacteristics when towing a trailer, ie ‘later’ upshifts, but I could be wrong.
I have a 99 lx470 for off road use. I keep it in 1st or 2nd for off road. I have kept it in D before and tranny temp crept up a bit. I believe it’s just natural behavior of the transmission anticipating a gear change so it slips the clutches and torque converter. When I put transmission selection in 1st or 2nd on lx470 the temperature fell quick.
Yes it is normal, as in, it is designed to "gear hunt" for maximize comfort. But this gear hunting causes transmission fluid to heat up under conditions you describe, as it is constantly preparing for a gearshift and/or uses a gear too high for grade/speed.
In many instances, Toyota expects drivers to use tools available on the vehicle for "non-standard" conditions. In this case, either using manual shifting or using 4L. Perhaps tow/haul mode may also help, as it may limit gear hunting.
- Moderator
- #118
Be advised......... When I asked the Dealer about installing a Toyota branded Xmsn cooler by a Toyota Dealer, I was told emphatically that it would void the Xmsn warranty (even if it was a Toyota cooler, installed by them).
I did use the tow/haul function....It did NOTHING at ALL!!!
I am taking to dealer on Monday (Kearny Mesa Toyota - Penske- San Diego). When I contacted them, they sais it is not normal. Will keep y'all updated.
I am taking to dealer on Monday (Kearny Mesa Toyota - Penske- San Diego). When I contacted them, they sais it is not normal. Will keep y'all updated.
I know that some of the folks that were towing with the new Tundra's were pinning the Thermostat open and it was helping, others were adding and external cooler. You can search more on www.tundras.com
www.tundras.com
Is it safe to pin open Transmission thermostat?
I might take you up on that thermostat. I honestly haven’t crawled underneath yet to look for the warming puck. I was mulling things over last night...
www.tundras.com
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