Towing w/o a tow package and slightly over the limit

Hi!

I know this has been asked a number of times already and I did read most of the posts, I wanted to provide some more information specific to my setup and see if anybody has been in a similar situation.

I have a 2005 Ford Explorer with the V6 4L engine, 4WD and the 3.55 rear axle ratio. Therefore my vehicle is rated for up to 3400 lb towing. I have added a class III/IV hitch.

I am looking at a travel trailer with an unloaded vehicle weight of 3500 lb and loaded close to 4000lb. The hitch weight will be about 300 lb. We do not typically load the vehicle too much. Most of the driving will be done on flat areas I do not expect to tow up mountains but would like to take long trips.

I talked to a Ford dealer and a mechanic I trust and they both said that I should be fine as long as I have a transmission cooler and do not push the car too far.

What do you think? Should I trust them? I have another option for another trailer that I do not like as much but is about 500 lb lighter however the hitch weight is about 500 lb (it only has a single axle)

Thanks!
Vassilis

 

[MountaineerGreen]

You should be fine, but you need to watch about loading up the camper with supplies, or the cargo area of your Explorer with supplies. It's easy to get 400 lbs of junk in a camper, plus a few people riding and their junk, you've got too much. Flat ground, short trips ought to be manageable, but hills, mountains and long hauls, the heat would really build in your trans.

 

[vasos]

Thanks for the reply!

Would monitoring the trans. temp help me adjust my driving or stop? I was thinking about using one of the OBD gauges, what would a normal temperature while towing be?

 

[thebrakeman]

With the Explorer, the MAX tow rating is only available when you have nothing in the truck except a driver. If you put 500 lbs of people in your truck, you only have 2900 left for the trailer, etc, etc.

Here is the 2005 Ford towing guide. You should go thru it for anything related to the Ex:
https://www.fleet.ford.com/showroom/rv_trailer_towing/2005/2005_Towing_Guide.pdf

Another way to look at this is starting from your GCVWR (combined vehicle rating). Per the towing guide, your GCVWR is only 8000 lbs. Subtract the empty weight of your Explorer (4469 per Edmunds.com), and you are left with 3531 lbs for the loaded trailer and any people and cargo in the truck. Typical family of 4 might weight 500 lbs. Subtract from 3531 and you have 3031 lbs available for the loaded trailer and any cargo in the back of the Ex.

Most campers end up 600-800 lbs over dry weight once loaded. Remember, "cargo weight" includes anything not included as standard from the factory (battery, LP tanks, water, roof A/C unit, etc). So it's not just your personal gear. Your camper will likely be more than 4000 lbs loaded.

So, you are likely to be more than 1000 lbs overweight.

Also, 300 lbs TW is not enough for a 4000 lbs trailer. For proper stability, any source recommends 10% minimum, which would be 400 lbs or more. At 300 lbs, a gust of wind, passing semi, or emergency lane change will put you into a very dangerous sway condition. Adding a friction sway controller would help, but that should not be a substitute for proper loading.

Finally, as a brake design and test engineer, I agree with the towing guide where it says the vehicle brakes are designed for use up to the Ex's GVWR (5880), NOT the GCVWR (8000 lbs). So, as soon as your combined weight exceeds 5880 lbs (which is only 1400 lbs over empty), you need to be using trailer brakes. This will require some extra wiring on your non-tow-package Ex, upgrading the 4-pin connector to 7-pin, and using an electric brake controller to let the trailer brakes actually function.

Sorry to be a party-pooper, but I do not think you should try towing anything more than a 3000 lbs popup as long as you run with trailer brakes. Without trailer brakes, I would not tow more than a 1500 lbs utility trailer.

 

[vasos]

I was working under the impression that the brakes were identical regardless of the towing package. I was told that the only difference with and w/o the tow package is:
- transmission ratio
- transmission cooler
- class III/IV hitch

If there are more differences such as the brakes then I would definitively not take any chances, can you confirm?

Thanks again, this is very useful information.
Vassilis

 

[skeeter123]

The tow package also includes the pre-wired 7-pin connector for the trailer lights and electric brakes, but you still need to purchase/install the brake controller. I don't know if there are real hardware differences in the brakes/rotors, but I would stick with the recommended tow weights as Thebrakeman said. If you're just doing some one-time towing (like moving a boat from one slip to another) you can push the limits; but you pay attention, concentrate, and cross your fingers. Sounds like you're preparing for regular trips with a TT. Sure, you don't want to burn up a transmission, but for safety it's all about braking. Like in the rain when someone cuts you off unexpectedly, or decides NOT to run the yellow light like any normal person would have. If you tow a lot, these things will happen. To get set for regularly towing, you want plenty of margin for your safety and everyone elses.
Hope this helps.

(p.s. a quick check of RockAuto shows that rotors and calipers for the 2005 4.0 and 4.6L are the same)

 

[thebrakeman]

There are no differences in the Explorer/Mountaineer braking system with or without the factory tow package. The thing to remember is that even with the factory tow package, you need to have functioning trailer brakes if the combined weight of both vehicles exceed the GVWR of the tow vehicle (in your case, about 5900 lbs).

I have an '06 Mountaineer with V8 AWD and factory tow package:
6400 lbs GVWR
7000 lbs max tow rating
12000 lbs GCVWR

But the same goes for me:
Since my brake system is designed for the GVWR (and NOT for the GCVWR), if my combined weight of truck and trailer exceeds 6400 lbs, I have to have functional trailer brakes.

And this makes sense. You want the truck's brakes stopping the weight of the truck, and the trailer brakes sized for the weight of the trailer...and the coupler holding the 2 together.

 

[vasos]

The trailer (Jay Sport 199) has electric brakes so I am planning to install a brake controller and sway bar / weight distribution hitch.

 

[vasos]

If safety (e.g. brakes) is not as much of an issue, I would be interested to hear from people with similar setups on any issues with the transmission (e.g. overheating etc).

Thanks again to all for the detailed responses!

 

[skeeter123]

I'm in the middle of getting my 2002 Exp XLT 4.6L V8 w/tow package ready for towing a 17' TT. I'm at 160K miles; I just replaced the rotors and pads w/Raybestos hdwr. I also am concerned about the 5r55w trans; so I recently flushed/replaced the ATF, and I've mounted a trans temp gauge in the cabin. ... I'm hoping to finish the job by mounting the temp sensor this weekend (I've decided to mount it in-line with the after-market Magnefine filter which is before the factory trans cooler) I didn't want to mess with drilling a hole in the pan for it. I want to see what my trans temp is for "normal driving" before I install an additional trans cooler. It's pretty flat here in FL, so I won't be seeing any mountain hauls. I expect I'll end up installing an additional trans cooler. When I get some temp data I'll post it.

You didn't say how many miles you have, but you may want to flush/change the ATF if it hasn't been done before. The owners manual may say its "lifetime" fluid, but a lot of the posters here (in the transmissions section) recommend changing it regularly (every ~30K miles).

Hope this helps.

 

[vasos]

I am also looking at a slightly lighter trailer (Jayco Sport 17Z) with 3000 lb dry weight and about 3400 lb loaded. This brings me right on the tow limit for the gear ratio I have. The 500lb might make a difference.

 

[thebrakeman]

Is it just you in the truck? No passengers? No luggage? Just an empty Explorer?

 

[vasos]

The truck will be loaded light, it will be about 320lb of passengers and about 150lb of camping stuff.

So totals (with the light trailer) will be 3300lb (loaded trailer) + 4469lb (car) + 450lb (passengers and luggage) = 8239 lb

That is 239 lb over the limit, is this too bad if the only difference is the gear ratio?

 

[skeeter123]

Just use GoogleMaps' new routePlanner feature to plot out a roundtrip route that's downhill in both directions; you'll be OK. :

 

[thebrakeman]

The truck will be loaded light, it will be about 320lb of passengers and about 150lb of camping stuff.

So totals (with the light trailer) will be 3300lb (loaded trailer) + 4469lb (car) + 450lb (passengers and luggage) = 8239 lb

That is 239 lb over the limit, is this too bad if the only difference is the gear ratio?

No, it's not horrible. You know the vehicle structure is up to it, and you upgraded the hitch. Be sure to get the brakes working, definitely add an aux trans cooler, and keep it out of OD when towing (to compensate for the gearing).

 

[skeeter123]

So I got the temp sensor installed, and took a 45-minute drive. No hills, no headwinds, 85-deg weather, not towing anything, not on Interstate. Trans temp sensor is in the ATF line output from the transmission, and before the factory trans cooler. (BTW I eye-balled the trans cooler, it's pretty big, looks like its half the size of the radiator) Trans temp took at least 15 minutes to warm up and level off at 125deg at 50mph, OD on. Interestingly, when I turned OD off, temp would rise to ~150-deg. OD off, back down to ~130. I know they recommend turning OD off when towing to keep trans from shifting in&out of OD; but I hadn't thought about the associated temp rise. I guess its better to avoid OD probs and take the higher temp (When towing). I think I'll still wait and see when I actually tow whether I'll install and add-on trans cooler.

I haven't seen any clear definition of transmission temperatures; does anyone have a towing-specific rule of thumb for trans temps? I.E. what's nice and low, what's a little warm, when should you just slow down, when should you pull over and let it rest, when should you jump out and make a run for it?

Thanks

 

[vasos]

I have seen previous posts mentioning 175deg as the max and 200deg as risking damage but don't take my word for it.

I have also read a few posts about using an OBDII scanner to read the transmission temperature. Anybody knows if this is possible on the Explorer?

 

[skeeter123]

yeah but most cars/trucks run the ATF through the radiator (and separate trans-cooler, if there is one), and most cars/trucks run at coolant temps of ~200deg; I don't know enough about it but is the coolant in the radiator that much cooler than when its flowing by the ect-sensor? Is the radiator path actually heating up my ATF?

ps Vasos I still recommend checking the ATF fluid/filter; if its never been changed now is a good time. When they say "lifetime" fluid they mean that when it dies they say "yeah, but its still got the original fluid in it!"

 

[thebrakeman]

skeeter,
To see why they want you to stay out of OD (or at least make sure it's not "hunting"), go back out, and shift in and out of OD about every 20 seconds or so using the accelerator pedal (to get both shifts and lock/unlock the torque convertor). You will probably see the temps go higher than 150.

That's the issue: Extra drag weight on a small hill can unlock the convertor, building heat. Keep it out of OD, and the rpm is high enough to be in the higher torque band, and not need to unlock the convertor. Likewise, a moderate hill could also require a downshift out of OD anyway.

For this reason, I will often tow in OD, but I don't use cruise control, but use a steady foot on the gas. No accelerator pedal increase......no hunting. If my speed goes up and down a few mph, fine. If more than that, THEN I pull out of OD.

 

[4 wheelin Nufy]

Vasos,
I have a Starcraft 16 RB which has a dry weight of 2900lbs and a full weight of 3500. My tow vehicle is an 02 Explorer XLT with the 4.0 V6 and it origanally had the 3.55's in the diffs. After towing it from the dealer in moderately hilly terrain I realized that it was borderline to heavy for my X even though it stated a 3500lb tow rating.