Towing a Travel Trailer Question

thewhitestallion · June 26, 2019

Ok, let me preface this by saying that I have towed in the past with this truck plenty of times, mostly just my atv (light) and my 02 Camaro (about 6k w/trailer) and it pulls those just fine. I am not new to towing trailers, just travel trailers. Also I am going to try and put a picture in here but since photobucket is all jacked up now I don't know if I will be able to. Just in case, the day this picture was taken was the day I picked up the trailer so the WD hitch is not set up properly so my truck is squatting a little too much and the trailer is not completely level. I plan on taking the time to set it up properly and also get air bags.

When I bought the trailer the 7-way plug was messed up and was wired so poorly that the brakes were not working due to terrible wiring methods. So I rewired it and took it on a test drive the other night to make sure all lights and brakes work as they are supposed to.

I live in Houston and it was night time about 85* with probably 100% humidity with a good amount of side wind, maybe 15 mph or so. I was driving on a flat freeway (like not one hill or overpass for MILES) doing about 60 - 65 mph at about 2800 rpm's in 4th gear and my trans temp was steady around 194 - 198 so I was good there. However, I noticed that my coolant temp was just a hair past the 210 mark which I thought was odd. The truck still had plenty of power and I could have easily gained speed if I wanted to. I figured maybe it is because it was locked in 4th and, relatively speaking, running at high RPM's for about 30 minutes or so. So I let off the throttle a hair so it shifted into 5th gear and tried to keep it in 5th but the temp either didn't move or lowered just a hair to where it was on the verge of being past the 210 mark (I'm talking a very small difference here). While doing this the truck did not want to stay in 5th gear and really wanted to be in 4th at that speed.

My question is, should I expect this every time I pull this trailer? The trailer is a 2005 Jayco Jay Flight 27bh and the manufacturer says it weights about 5k dry but my weigh safe hitch put the tongue weight of the trailer around 600 - 650, so It probably is weight closer to 6k lbs right now (I plan on hitting the scales soon). I just feel like this really is not that much weight for the trucks towing ratings which is just over 9k. So I feel like the truck should be able to pull it easily without the coolant temps rising ESPECIALLY at night. I plan on pulling it through the Texas hill country which I do expect the temps to rise a little on steep grade.

Anyone have some personal experience they could chime in with? Is that temp normal? Is that speed vs gearing normal? My truck is a CCSB 5.3 z71 4x4 w/ 3.42's with 122k miles. All the maintenance has been done myself except I had the dealer to the trans flush. I use mobil 1 every 7k miles, new filters when they get dirty and the maintenance mentioned below.

My theory is my coolant mixture is not exactly 50/50. I did some preventative maintenance about 2 months ago, I changed all three belts, water pump, upper and lower radiator hoses, thermostat and new coolant (water pump is AC Delco and so is the thermostat, belts and hoses are gates for what it's worth). I premixed the coolant myself by "eye balling" the 50/50 mixture. So maybe I have 60 coolant and 40 water (who knows) which would make it harder to cool the vehicle because the coolant does not dissipate heat like water. So I do plan on draining the coolant and buying the premixed 50/50 to be100% sure it is mixed correctly. As soon as I stopped the coolant temp lowered to normal about 200 - 210. So I know my cooling system is working properly.

thewhitestallion · June 26, 2019

Here is a picture of my gauges as I am driving. Sorry that it is kinda blurry as well, I was driving.

Capt Bob · June 26, 2019

Sounds almost identical to my bone stock 2018 pulling my 5000 lb. boat and trailer in 94 degree heat on flat ground. I'm guessing until I change out the T-Stat, it will be the same.

2kwik4u · June 26, 2019

Sounds about normal to me. I just finished a 600mi tow with a little lighter load (4k boat/trailer with 4 people and gear for a week). Temps spiked a few times, but came down quickly when back to flat ground. I wasn't pulling nearly the "sail" that you are, so I spent more time in 5th than 4th. Any of the hills between Lexington, KY and Knoxville, TN that required a drop to 4th would spike the temp. Once on the back side and going downhill they would relax a bit back to "normal".

I monitored the coolant temp via the Torque Pro App, and BlueTooth OBD2 adapter. Never saw above 218, and ran around 205-207 most of the time. Ambient temps were in the mid 80's with like 90% humidity. Elevation ranged from 500-1,000 ft asl. Had the cruise set on 70 most of the way after monitoring bearing and tire temps for the first 60 miles or so.

There was a thread around here not to long ago from a guy who was testing the fan settings for towing. He was able to show a marked improvement on long pulls up steep grades by turning the fan on earlier, and running a slightly cooler thermostat. I can't find the thread to save my butt this morning, but it was a very interesting read. If you're concerned about temps while towing I would find that thread, and implement his changes (if possible).

*edit* Appears my Google-Fu just needed some coffee. Here's the thread:

Edited June 26, 2019 by 2kwik4u

thewhitestallion · June 27, 2019

That is good info and makes me wonder if I should tune my truck at get the 180* thermostat. I don't plan on towing this trailer all that much but when I do, I would like to feel little more confident that I am not going to bake my drivetrain.

kenny_r · June 27, 2019

Pulling decent grades in warm temps my 2011 5.3 and 3.42’s would read around 215-220 coolant and 230 trans. That’s pulling roughly same weight as you. Basically 3rd and 4th gear for an extended period of time.