Tranny Temp HOT!

ptvolly · 01-27-2007, 04:14 PM

Took a trip this weekend, about 300 miles one way. Had to tow my trailer (16' landscape style) and 1 ATV (Polaris 700). In other words, hardly any weight at all. Had 3 people in the truck, average about 220 lbs each. So yeah, other than us guys, hardly any weight at all.
I had the truck in overdrive (always have used it, but usually make the same trip with 4 ATV's, bed full of crap, and another guy in the truck). Big key here is, I did NOT have the tow mode on! Not sure why I didn't, guess I just forgot.
About an hour into the trip I happen to check the tranny temp gauge and to my surprise, it is RIGHT AT the "hot mark" (not pegged, but dead even with the mark just below that) Now, I've towed the loaded trailer the same route probably 15 times and never gotten the needle to rise above horizontal, the ONLY truck difference being the tow mode activated. So what did I do? I dropped the truck into 4th gear, and the gauge IMMEDIATELY dropped to below horizontal. No delay at all other than the 2-3 seconds it took the needle to drop. Left it that way for the rest of the trip.
It was surprising to me, because of the amt of weight being towed at 70 mph, in clear 29 degree weather, that overdrive would make the tranny get that hot.
What surprised me the MOST though, is how quick the gauge dropped to "normal". It wasn't like it was stuck, but seriously only took 2-3 seconds. So everyone has my endorsement to NEVER tow in overdrive, without tow/haul being activated! Just thought I'd share.

got_titan · 01-27-2007, 05:22 PM

when towing the owners manual states to drive in 4th gear...everyone that drives in 5th while towing reports the same as you......

Yahooligan · 01-27-2007, 07:02 PM

Quote:

Originally Posted by got_titan

when towing the owners manual states to drive in 4th gear...everyone that drives in 5th while towing reports the same as you......

I keep looking for the page that says that, I've yet to find it in my '05 manual or the '06 manual on nissanusa.com.

I did tow a 23' toy hauler on level ground in 5th without the trans temp heating up.

Different results for different situations, that's why the gauge is so nice to have. Simple logic, if it heats up while driving a certain way, simply don't drive that way.

I, too, was surprised as how quickly the trans temp dropped after downshifting (4th -> 3rd on a grade).

**loufish** · 01-27-2007, 08:23 PM

Quote:

What surprised me the MOST though, is how quick the gauge dropped to "normal". It wasn't like it was stuck, but seriously only took 2-3 seconds.

That sounds funny, you can't cool down a trans in 2-3 seconds...What's even funnier is that all most can find about the "tow mode" is later shift points around town, nothing else it does would account for the quick cool down other then shifting out of 5th...

Learjet · 01-27-2007, 08:31 PM

tow in 4th, tow up a large hill in 3rd. This will help your engine, torque converter and transmission in the long run.

Page 9-33 '06 owners manual...says "downshift up a hill".

Page 9-34 '06 owners manual..."do not tow in overdrive"

Yahooligan · 01-27-2007, 08:34 PM

Quote:

Originally Posted by loufish

That sounds funny, you can't cool down a trans in 2-3 seconds...

If the RPMs are low enough, the trans will be working hard and generating a fair amount of heat without enough fluid flow. The fluid going into the trans is plenty cool, so when you downshift the trans pump speed increases, as does the fluid flow, and the fluid coming out of the trans is a lot cooler in a very short amount of time.

This isn't a problem with an inadequate trans cooler, where the cooler can't keep up and the fluid going back into the trans isn't sufficiently cooled, this is a problem with low fluid flow which is unable to carry the heat away from the trans fast enough.

You can cool down the temp of the fluid coming out of the trans in 2-3 seconds...

Clint · 01-28-2007, 09:22 AM

Go get your fluid changed, the extra heat may have burned it some. I'd rather spend the $200 now rather than $3000 on a new trans. later.

Clint

AMCS · 01-28-2007, 02:14 PM

I had a similar situation occur. I was towing a snowmobile trailer with one sled uphill in "D" without tow mode on. As you did I downshifted and the temp dropped. I think there may be a connection to the low ambient temperatures. Have never had the problem since.

04 KC LE, OR, BT

ptvolly · 01-28-2007, 06:24 PM

Quote:

Originally Posted by Yahooligan

If the RPMs are low enough, the trans will be working hard and generating a fair amount of heat without enough fluid flow. The fluid going into the trans is plenty cool, so when you downshift the trans pump speed increases, as does the fluid flow, and the fluid coming out of the trans is a lot cooler in a very short amount of time.

This isn't a problem with an inadequate trans cooler, where the cooler can't keep up and the fluid going back into the trans isn't sufficiently cooled, this is a problem with low fluid flow which is unable to carry the heat away from the trans fast enough.

You can cool down the temp of the fluid coming out of the trans in 2-3 seconds...

That makes since why it would have dropped so fast then! Especially since I was going up some long gradual grades and doing what I could to not have it downshift without loosing too much speed = low rpm.
I guess I'd like to say I never tow in "5th", but usually I do, just with the tow mode activated, more weight, and no problems at all.

Shane06fl · 01-29-2007, 05:48 PM

It's never good to tow in the highest gear or over drive, even though I do it. When dragging around a 25ft tri axle trailer (3000lbs) with a 3000lb Kubota tractor I use 4th with no problems. When dragging my 18ft bass boat I use 5th, no problems. When dragging my 16ft tandem axle landscape type trailer (1500lbs) with 3 ATV's (1500lbs) a 4th ATV in the bed (400lbs) 4 people in the cab and 4 peoples worth of weekend hunting and camping gear I tow in 5th with cruise control at 70-75mph all over the place and have no problems. Even on the hills in Georgia it will down **** to 4th and back to 5th after the hill, there is no hunting for gears like in my buddies Chevy 1500HD towing less weight( did I tell that bothers him

) In the real hilly stuff I use 4th on the highway but most of the time on the highway 5th gear is doing great. Never had the tranny temp get more than half way.

John S · 01-31-2007, 05:19 PM

I've been towing my 18' open trailer with track car (gross weight 5000) and I never use the tow mode. Even in the hot summer, my tranny temp gauge never budged above a bit over the half-mark.

What's the fuel economy difference towing between the TOW MODE and without?

Wildmike · 01-31-2007, 07:20 PM

Put in reformulated Amsoil ATF ASAP. I don't think Nissan J-matic is a synthetic. Synthetics should run 100K or more in a tranny. Not 30-50K like the Titan manual says.

**loufish** · 01-31-2007, 09:07 PM

Quote:

don't think Nissan J-matic is a synthetic. Synthetics should run 100K or more in a tranny. Not 30-50K like the Titan manual says.

I'd be VERY suprised if it was NOT synthetic, all the late model trans fluids are...If you aren't towing, I agree the 30,000 mile service seems a little too soon, but towing can spank the trans fluid...

20Titan05 · 02-14-2007, 03:49 PM

Quote:

Originally Posted by Yahooligan

If the RPMs are low enough, the trans will be working hard and generating a fair amount of heat without enough fluid flow. The fluid going into the trans is plenty cool, so when you downshift the trans pump speed increases, as does the fluid flow, and the fluid coming out of the trans is a lot cooler in a very short amount of time.

While this sounds somewhat convincing, it's not correct. The temp gauge is located near the torque converter. In the towing you were doing, you were driving in 5th gear with the t/c unlocked. When you shifted to 4th, the t/c locked up. No more slipping, not more INTENSE heat, gauge drops down quickly. This indicates that the overall a/t fluid temp was not as hot as the fluid near the gauge pickup. If it were me, I'd inspect the fluid before replacing it.

StuntDriver06 · 02-14-2007, 04:23 PM

guess i can be glad i traded my 06 non-BT that i used to tow 4000lbs to florida and back at around 80-95mph on I-95, who knows how hot the tranny would have gotten....

wait i just remembered, i used a handheld infrared thermometer on the tranny and diff at fuel stops, rear end was around 165, tranny was around 172, that is case temp though... i checked it right when i stopped and before i left, only 1-2degree difference...