2013 new owner towing report

[cycho]

Ok it's been a few months, 2500 miles and a few trips to the Northland...

I have a GMC Sierra extended cab 4.8 (purchased new, now at ~168k miles) and this 2013 Tahoe 4X4 LTZ 5.3 with 73K on the clock.This thing is a beast! It's takes a bit to get used to but overall I should have bought a Tahoe a long time ago. In fact I still kick myself for not buying a Blazer when I bought my first new vehicle in 1978. That's when I bought a 4X4 short bed Chevy. Really enjoyed that truck but with three kids at the time, a Blazer would have been a better choice.

I don't drive the Tahoe much because we trying to keep the mileage low. We are retiring next year and it's intended to be our last vehicle. We make bimonthly trips to our retirement home which is 150 miles up into the Ponderosa Pines (on the rim as they say in AZ). There are two stretches of highway with several 6% & 7% grades to climb both ways. The longest 6% being 5 miles, the longest 7% being 3 miles. These give the Tahoe problems when towing my 20 foot enclosed trailer.

The trailer weighs about 2800 lbs dry. I figure we were pushing 4000lbs on the way up and empty coming come. Going up was at night so still about 100° in the beginning down to 65° for the last hill. Coming home was late afternoon. Most of the hilly terrain was run in the low 100° temperature. Coming into Phoenix it was 109°.

On the way up the Tahoe coolant temperature reached 235° while the trans temp reached 225° on the steepest portion of the highway. On the way home the coolant once again reached 235° but the trans temp got to 235° on the long 7% grade. This was running about 3K rpm in 2nd gear (i had more pedal but was afraid it would over heat more) . The Tahoe doesn't have an external trans cooler but this is very disappointing just the same. My old GMC pick up out pulls the Tahoe and never overheats! Both have high gear ratios.

Once in Phoenix at 60 - 65 mph on the freeway the trans temp ran 215° to 220° the rest of the way home. Out side temp was a steady 109°. Is this just too much trailer for a high geared 5.3 Tahoe in this AZ heat? By itself or pulling an 8 enclosed trailer the Hoe is awesome!

I just bought a TRU COOL MAX trans cooler but at 108 to 113 everyday it will be a while until I tackle the install. At this point I'm not sure if the transmission itself is over heating or if it's the engine coolant/radiator heating up the trans oil?

Edited Trans temps + 100°

 

[intheburbs]

So, let me get this straight, you're worried about your transmission getting up to 135°? Are you talking Fahrenheit or Celsius? I'm honestly very skeptical that your transmission stayed below 135°F in 100-degree heat pulling a 4,000-lb trailer with no trans cooler. Are you sure the previous owner didn't install an aftermarket cooler? These trucks are designed to have the transmission running at 180-190° F. My Suburban, with the factory trans cooler, generally runs 100° hotter than the outside temperature when I'm NOT towing. I see no way your transmission stayed that cool without an external cooler.

 

[CrashTestDummy]

Yeah, 135-deg F is not that bad. I'd be MUCH more concerned with the 235-deg F coolant temps. Any were you running in second? No wonder the engine got so hot.

 

[gooffeyguy]

Those trans temps seem low, especially while towing. What are they normally when not towing?

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[gpracer1]

Something is not right. Either the trans temp sensor is bad or you are talking C.

I’m in Phoenix also and with an LTZ with all the options including K5L cooling package with external trans cooler and 3.42 rear end and my trans temps are 185-195 NOT towing in the Phoenix heat at around 110 degrees. With a 21 ft 4000lbs of boat I’m about 200 degrees on the highway.
Up to the rim is more extreme for sure. I tow a 7000 lb 10ft high travel trailer and there are some beast mountains for sure. I wouldn’t do it with my Tahoe unless I had to. I did it with my heavily modded 99 Tahoe and it was at its limit but only for 1 year till I got the 2000 F350 CC Dually 7.3 with mods.

 

[cycho]

Sorry...add 100° to each of those trans temps I wrote

 

[swathdiver]

2013 Tahoe 4X4 LTZ 5.3 with 73K on the clock.This thing is a beast!

It's time to change your fluids. The radiator coolant is good for 5 years or 150K, whichever comes first, well, time came first in your case. The transmission and fluid can take the higher temps but the fluid still breaks down, wears out, faster. Change it every 36K miles or sooner with the towing you're doing.

When you put clean fluid in those differentials and transfer case, she's going to run even smoother, watch! 3.08 or 3.42 gears? Single speed transfer case?

 

[cycho]

It's time to change your fluids. The radiator coolant is good for 5 years or 150K, whichever comes first, well, time came first in your case. The transmission and fluid can take the higher temps but the fluid still breaks down, wears out, faster. Change it every 36K miles or sooner with the towing you're doing.

When you put clean fluid in those differentials and transfer case, she's going to run even smoother, watch! 3.08 or 3.42 gears? Single speed transfer case?

Hi/Low transfer case, 3.08 gears

 

[swathdiver]

Hi/Low transfer case, 3.08 gears

That's a new one for me to see, a 2-speed TC with 3.08s, interesting. I think it was in 2010 that they started pairing the MP3010s with 3.08 gears and the MP3023s with 3.42s, which was the original setup in 2009.

 

[cycho]

That's a new one for me to see, a 2-speed TC with 3.08s, interesting. I think it was in 2010 that they started pairing the MP3010s with 3.08 gears and the MP3023s with 3.42s, which was the original setup in 2009.

I'll check the gearing again tomorrow, but the 2 speed TC was a big reason for my purchase.

 

[cycho]

Yeah, 135-deg F is not that bad. I'd be MUCH more concerned with the 235-deg F coolant temps. Any were you running in second? No wonder the engine got so hot.

Yeah well I was going up a 7% grade and ran out of options in 3rd

 

[cycho]

Something is not right. Either the trans temp sensor is bad or you are talking C.

I’m in Phoenix also and with an LTZ with all the options including K5L cooling package with external trans cooler and 3.42 rear end and my trans temps are 185-195 NOT towing in the Phoenix heat at around 110 degrees. With a 21 ft 4000lbs of boat I’m about 200 degrees on the highway.
Up to the rim is more extreme for sure. I tow a 7000 lb 10ft high travel trailer and there are some beast mountains for sure. I wouldn’t do it with my Tahoe unless I had to. I did it with my heavily modded 99 Tahoe and it was at its limit but only for 1 year till I got the 2000 F350 CC Dually 7.3 with mods.

I run a little over 200 in the Phx heat. An I-17 trip from McDowell North to Peoria and I'm 215 with the 20ft trailer loaded with one Harley Trike. Back South empty is around 207. Never had a trans temp gage so I had no idea what it should be.

 

[cycho]

So, let me get this straight, you're worried about your transmission getting up to 135°? Are you talking Fahrenheit or Celsius? I'm honestly very skeptical that your transmission stayed below 135°F in 100-degree heat pulling a 4,000-lb trailer with no trans cooler. Are you sure the previous owner didn't install an aftermarket cooler? These trucks are designed to have the transmission running at 180-190° F. My Suburban, with the factory trans cooler, generally runs 100° hotter than the outside temperature when I'm NOT towing. I see no way your transmission stayed that cool without an external cooler.

Sorry make that 235°...

 

[Costal_Cat]

Hi,
I just posted this over in https://www.tahoeyukonforum.com/threads/towing-and-temperature-issues.112752/page-3#post-1359846

I'll post below for ease of reading but do as @swathdiver suggest do your fluids and then get that TruCool installed and you will be fine....

*************** SNIP****************

Just thought I would post my experiences out there based on my towing.

2012 Denali XL. I got the truck with around 80k on it I think and now have around 135k. I have posted about the temp and towing in several threads but here is a recap of what I have done over time. I like to do one thing at a time and then see how that affects the truck before moving on to the next thing.

I tow a bit mostly in the SE up and down 95 and out 40 to Tennesse and the NC mountains. I have slowly been working on the towing setup. I added bigger and better bump stops in the rear, new shocks and compressor for the rear, converted to passive vs eShocks when I did that. Replaced the trans filter and replaced the fluid. I have flushed it myself by doing the disconnect from the radiator with 3/8th tubing into a 5-gallon bucket while one daughter is filling with new and the other daughter is turning the engine on and off until it was pumping out clean. Flushed the cooling system completely and refilled with dex-cool. That is pretty much the order I approached things and each item improved either ride, handling or temps. The last big trip that ran up the temp was in May over memorial day and the temp in NC & SC got into the 90's. On the 7 hour ride back to the NC coast from our camping trip with the travel trailer the water temp and trans were just too hot IMO. The last thing in my view was to replace the trans cooler with the TruCool 40k. So this past Thursday I did that and immediately saw a huge difference in temp control.

2.5 hour trip up I40 in this crazy heat without towing middle of the day my temp was around 178 - 185, once I hit stop and go it went up to 190's
With the new cooler and no towing in this same heat and route the temp never got about 145 in stop and go and once I was on the interstate and up to speed the temperature dropped to 135 - 142 consistently. Even Friday evening with the heat, I pulled into the driveway and the temp was reading 129 which I have never seen after driving any time of the year.

Now I have not been able to tow a long distance yet but I did grab the boat and the same route from the house to the boat ramp last week the temp was in the 180's, same trip the temp stayed around 148 and only once got up to 153 and as soon as I was moving it was back under 150 in just a few minutes.

So all the things I have done I know have helped incrementally but the TruCool has been the best so far in my view for temp control....

 

[swathdiver]

I'll check the gearing again tomorrow, but the 2 speed TC was a big reason for my purchase.

Four Low has gotten us out of a few jams of our own making while playing off-road. 4LO also made some really sandy stretches of Daytona Beach easy peasy.

 

[intheburbs]

Four Low has gotten us out of a few jams of our own making while playing off-road. 4LO also made some really sandy stretches of Daytona Beach easy peasy.

4LO allowed me to pull a 20-ton garbage truck out of a ditch.

 

[cycho]

Hi,
I just posted this over in https://www.tahoeyukonforum.com/threads/towing-and-temperature-issues.112752/page-3#post-1359846

I'll post below for ease of reading but do as @swathdiver suggest do your fluids and then get that TruCool installed and you will be fine....

*************** SNIP****************

Just thought I would post my experiences out there based on my towing.

2012 Denali XL. I got the truck with around 80k on it I think and now have around 135k. I have posted about the temp and towing in several threads but here is a recap of what I have done over time. I like to do one thing at a time and then see how that affects the truck before moving on to the next thing.

I tow a bit mostly in the SE up and down 95 and out 40 to Tennesse and the NC mountains. I have slowly been working on the towing setup. I added bigger and better bump stops in the rear, new shocks and compressor for the rear, converted to passive vs eShocks when I did that. Replaced the trans filter and replaced the fluid. I have flushed it myself by doing the disconnect from the radiator with 3/8th tubing into a 5-gallon bucket while one daughter is filling with new and the other daughter is turning the engine on and off until it was pumping out clean. Flushed the cooling system completely and refilled with dex-cool. That is pretty much the order I approached things and each item improved either ride, handling or temps. The last big trip that ran up the temp was in May over memorial day and the temp in NC & SC got into the 90's. On the 7 hour ride back to the NC coast from our camping trip with the travel trailer the water temp and trans were just too hot IMO. The last thing in my view was to replace the trans cooler with the TruCool 40k. So this past Thursday I did that and immediately saw a huge difference in temp control.

2.5 hour trip up I40 in this crazy heat without towing middle of the day my temp was around 178 - 185, once I hit stop and go it went up to 190's
With the new cooler and no towing in this same heat and route the temp never got about 145 in stop and go and once I was on the interstate and up to speed the temperature dropped to 135 - 142 consistently. Even Friday evening with the heat, I pulled into the driveway and the temp was reading 129 which I have never seen after driving any time of the year.

Now I have not been able to tow a long distance yet but I did grab the boat and the same route from the house to the boat ramp last week the temp was in the 180's, same trip the temp stayed around 148 and only once got up to 153 and as soon as I was moving it was back under 150 in just a few minutes.

So all the things I have done I know have helped incrementally but the TruCool has been the best so far in my view for temp control....

Thanks, should I bypass the radiator when installing the TruCool or run them in tandem?

 

[Costal_Cat]

Thanks, should I bypass the radiator when installing the TruCool or run them in tandem?

Do you have a stock Cooler? If so just directly replace that. If not the process is a little more entailed but mine, which replaced the little stock one, does go through the radiator and I kept it that way.

 

[swathdiver]

Thanks, should I bypass the radiator when installing the TruCool or run them in tandem?

Keep the radiator cooling; install the external one so the fluid goes into the radiator BEFORE the TruCool.

Whew, I wrote that backwards, fixed now.

 

[cycho]

Do you have a stock Cooler? If so just directly replace that. If not the process is a little more entailed but mine, which replaced the little stock one, does go through the radiator and I kept it that way.

The fluid goes thru the radiator before or after the cooler?