overheating tranny on tow vehicle

[Duncan]

We tow with a 2009 Nissan Armada LX 4WD with tow package.

On steep grades, like at most core lakes (Lake Norris, Lake Norfork), the tranny cooler temp will almost immediately peg on HOT (tranny temp gauge). This occurs in 2WD, 4WD HI, and 4WD LO, with or without two mode engaged. The temp has also pegged pulling up a steep grade (but it was very steep coming up out of Lake Norfork).


Temp does not peg on normal roads or the interstate (but steepest grades have been around Lake Norris, TN).

Tranny fluid is not low.

Any ideas?

[kerlee]

we used to pull our rz2 with a escalade esv and would have the same issue, as soon as we put a strain on the engine going up a hill, the temp would just jump up there. this happened only in the real hot months (ie. when we use the boat most). Talked to my mechanic and he called the transmission shop where he sends all his work out to and they said about the only thing we could do was add an additional transmission cooler to the existing transmission cooler. Looks like your vehicle as well as our old escalade had the towing capacity but the transmission coolers are not big enough like the bigger trucks. I ended up upgrading to a 3/4 ton diesel truck for that reason and a couple of other reasons, no problems now going up hills now

[zany]

I have a temp gauge on my Denali, What is max temp you should let you tranny get to before you should start to worry?

[Duncan]

I have a temp gauge on my Denali, What is max temp you should let you tranny get to before you should start to worry?

For me, I started to worry when the gauge was pegged all the way to hot

[ajholt7]

Trade me your RZ for my 20v. Problem solved. Or get a 3/4 truck. I will never own another 1/2 ton after owning my diesel.

[G-MONEY]

Do you have a trans cooler? If not you need to get one or up grade to a bigger one. Also check your fan clutch make sure it is changing speeds when your temp is starting to get hot. What kind of RPM's/MPH's are you doing when pulling the hills? Are you dropping your truck in to second gear or are you keeping it in drive / overdrive?

[Duncan]

Do you have a trans cooler? If not you need to get one or up grade to a bigger one. Also check your fan clutch make sure it is changing speeds when your temp is starting to get hot. What kind of RPM's/MPH's are you doing when pulling the hills? Are you dropping your truck in to second gear or are you keeping it in drive / overdrive?

Yes re trans cooler.

MPH up hills was low (5-10 mph). I tried both drive and dropping down to lower gear and both had the same heat up.

The dealer this afternoon said it looks like one temp sensor shows normal temp and the second temp sensor shows high temp. So the problem might be sensor-related. Here's hoping.

[kerlee]

here is a link to transmission temp and transmission failure.

http://www.txchange.com/heatchrt.htm

If you don't have numbers on the gauge, then it would be hard to figure out what the red zone meant.

[samw]

I have a temp gauge on my Denali, What is max temp you should let you tranny get to before you should start to worry?

Zany, I just got rid of my 02 Denali XL. What I was told under normal towing IE-interstate/Hwy driving normal sort of hills it should run no hotter then what your engine temp is running. My Denali always ran right with my engine temp, a tad hotter if it was 90 plus out side and running more hills.

I now have a 07 Escalade ESV, I hope for no tranny temp issues.

[Duncan]

The dealer spoke to corp Nissan and was told everything on the heat dial is "normal operating conditions" and software will shut down the tranny if it starts getting to hot. This happened once when pulling up an incredibly steep and long switchback out of Norfork.

Corp Nissan refused to say we needed an aftermarket additional tranny cooler. But the dealer suggests that is what is needed. And I agree.

Anyone have suggestions as to a favorite brand or model of tranny cooler?

Thanks for all the feedback.

[bwrag]

I would get a transcoller and gears

[boatwakes]

Get a B&M in the LARGEST size you can get (i.e. 26,000lbs rating or more) or check out summit racing online, they have large coolers with thermostatic fans. It's just a matter of mounting capability/available area but go as big as you can. Good luck

[Fast1911]

I will never own another 1/2 ton after owning my diesel.

Diesel Power Baby