I took advantage of lockdown to work on the tow plate for the Suburban. Now, my Winnebago View ideally should not tow something this heavy. That’s what I bought the Smart for, which I have written up a couple of times already. Stopping is the more important concern than pulling the weight. I have seen C Class RV’s, built on a Ford or Chevy van chassis, pulling full size pickups and the like. I recently passed a View like mine, on a Sprinter chassis, flat towing a Tahoe.
If you are willing to take it easy, you can stay safe. I’m one of those annoying people that generally stays in the right lane at 62 mph or so in the RV (or when pulling a camper or the boat), even if the speed limit is higher. It’s safe and stable at that speed, and you can get stopped relatively quickly.
But, when I bought the View from my parents, they gave me all the flat tow equipment they had. The setup would be $2,500.00 or more. Since I had all that equipment given to me, all I needed was a “tow plate” for the Suburban, which was less than $400.00. This is what would enable you to tow it with any RV. So, I figured I would go ahead and set it up, for that price. Maybe I won’t use it unless I have a bigger RV someday. I also wanted to try out my installation skills on the Suburban before I tackled the tighter confines of the Smart.
I think towing with the View on a flat trip would be fine, such as the Atlantic Coast or Florida, from where I live. My house is about 800 feet above sea level, so the beaches are a gentle 250 miles to the East. I would not head 35 minutes north of my house to the Eastern Continental Divide, trying to pull the Suburban with the View. That point along the ECD is about 4,000 feet, so that’s a pretty strenuous drive.
When you flat tow, you are not putting any weight or “vertical load” on the RV hitch. The towed vehicle is sitting on its own wheels on the ground, and just being yanked around. This makes a big difference in tow vehicle capability. In Europe, you see lots of C-Classes pulling 26 foot campers, that we Yanks would reserve for the Power Stroke dually F350’s. The difference is, they load the trailers differently so there is little vertical load, and they go slow, typically 45 mph or less.
With the optional Chevy “Max Tow” package I have, you get a different transfer case with 2WD, Auto, 4H, 4L, and neutral settings. You cannot flat tow any of the big GM SUV’s without this transfer case. You put it in Neutral by holding the switch all the way clockwise, until the faint “N” you see here lights up.
The tow package also adds in the integrated trailer brake controller seen to the right of the selector knob, an air leveling rear suspension, full size spare, and heavy duty cooling and alternator from the Tahoe police package. A good deal at $500.00.
The transfer case mounts to the output on the transmission, which enables it to serve as a disconnect to both the front and rear driveshafts. Once you go through the steps to ensure the case is in neutral, you actually leave the transmission selector in “P” to then flat tow the Suburban, all four wheels on the ground.
You can also flat tow any manual transmission car, front or rear wheel drive, by simply leaving it in “N”.
First step was to remove the “nose”. It’s all one piece, held on with a dozen push/pull pins, and about 30 small bolts and washers. The red rags are to keep the painted corners from scraping the concrete.
And this is what you are left with. I spent a long time just examining all the newly exposed inner workings. You see the powered louvers here, which close when engine cooling demands allow for it, for better fuel mileage. I had heard they were there, but you couldn’t see them before.
There’s a half dozen stickers on the naked front pieces that simply say “CHEVY”. Especially before the headlights are mounted, I imagine the Arlington line workers can’t be sure what they are looking at. The Tahoe, Suburban, Yukon variations and Escalade twins are all built side by side, at that one plant, for the world.
The paint on the driveway is courtesy of my two teen boys, who wanted to paint a Charlotte Hornets colored court under the goal. Prior to the lockdown, I would have maybe vetoed that, but hey why not. Just trying to keep everyone entertained.
The tow plate itself is pretty hefty, and simple. It bolts to the end of the frame rails, using a combination of factory holes you have to enlarge, and new holes you have to drill. I was dreading the drilling, but with a sharp new 9/16 bit rated for metal, it went fine. All the hardware comes with the plate, and you provide the red threadlocker. Getting it installed is a two person job for sure; my 18 year old got under there and held it up, until I could get a bolt hole drilled out and installed on each side (he wore safety glasses of course).
When you want to connect the vehicle to the tow bar, you insert and twist these locking pins. They remove for a cleaner look, and to be safer for the shins. The other connection eyes lower down, are for the safety chains between the RV and the towed vehicle.
The looped black wire is for the disconnect switch. Required by U.S. and Canadian law, if the towed vehicle comes disconnected from the RV, a light duty coiled cable connected to the RV hitch, will pull the pin out of the disconnect switch. You see it there with a zip tie on it. The looped black wire will be routed into the driver floor area, where the brake attendant machine will reside. If the pin is pulled, the safety switch will tell the brake attendant to apply full brakes and stop the runaway Suburban.
I was happy enough with the cutting on the bumper. That was not the hardest part, but the part I was the most nervous about. It is all a very tight fit back there on vehicle with radar cruise control and dynamic braking, both of which I have. I could not drill the holes in the bumper any more towards the center of the car, due to a structural member. On cars without the two radar features, the pins would be several inches towards the outside edge of the bumper, and you would not have that interference issue.
I decided a neat, uniform round hole with a hole saw, would be a better look than trying to cut a smaller hole, say with a Dremel tool. And the black area of the bumper can be removed from the rest of the painted bumper, if I decide I want to redo it someday.
That was the end of the first day. It took about 6 hours of nonstop work, but it was my first attempt. I’m sure someone who does these for a living could do it in half the time, or less.
Next up, I need to plan the wiring. You need power for the brake attendant off a cigarette lighter outlet, which uses its own compressed air pump to operate the regular brake pedal. However, you don’t want to run the car battery down by the brake attendant cycling on and off a lot, which can be a problem on long trips.
Also, the Suburban tow instructions require you to disconnect the battery, to keep the electronic steering wheel lock inactive, so the car can follow the RV. So, I can’t use the Suburban’s battery to power the cigarette lighter outlet, anyway.
There are ways around all this.
1. You can hack into the car wiring to get a charge coming in off the 7 pin connector on the RV, to effectively trickle charge the towed car as you go down the road. This would not help if you have to disconnect the battery, like I do.
2. You can also take a compressed air feed off the RV, if you have a large RV with air brakes (I don’t), to feed the brake attendant with compressed air.
3. Or, you can leave the brake attendant set to only come on in “emergency” braking, which is what my parents did. They were pulling a 2011 Subaru Forester, though, so they just dawdled along and counted on the View brakes doing most of the work. The attendant came on only in a “panic” stop, so it didn’t run the Subaru battery down. Also, they had a key ignition, so you just left the key in the correct position to unlock the steering wheel.
The Forester weighs more than I thought it did (3,400 pounds), but the Suburban of course weighs quite a bit more (5,791 pounds at the factory door, according to a shipping manifest I found under the seat). I need the attendant to come on regularly and help out, so it will cycle on a lot. I’ll actually probably set it to “bite”, meaning it comes on with enough force to help the RV stop, instead of the other way around. Suburban brakes are cheaper than Sprinter brakes.
My solution was to take advantage of the second, unused battery tray under the hood. Since the Tahoe and Suburban have law enforcement applications, they have a second tray for a “house” battery to help run radios and related equipment. The versions of this vehicle equipped with the 6.2 liter engine do not have this tray, such as the Denali and Escalade. Other under hood equipment is placed there with the 6.2, to the great disappointment of Denali and Escalade owners on RV chat groups.
On the Advance Auto website, I found a chart of the battery sizes, and measured the unused battery tray.
A Group Size 24 deep cycle battery would fit about perfect. The deep cycle batteries have the usual automotive posts like you would use in a boat or RV application, but also the threaded studs for more connection options. I then wondered what made a deep cycle battery different, and went down a Wikipedia rabbit hole on that topic:
https://en.wikipedia.org/wiki/Deep-cycle_battery
So you can read up if you like! The battery I bought is a cheap, old tech “flooded” lead acid battery for $89. You can spend three times that for the newer types, and maybe they are worth it for a more important application (like medical equipment) or a more constant duty cycle. As it is, I’m not planning on this battery being put to work running the brake attendant, more than a handful of weeks a year.
I also bought a battery tie down strap intended for a boat or RV battery, since there is a tray under the hood, but no tie down provision.
My plan was to install a deep cycle battery there, and run a standard connection into the driver footwell area with the red and black wire you see here. You could then use the same connection for a 12 volt outlet to run the brake attendant (which has a cigarette lighter power plug), OR, connect a charger occasionally when parked to charge the deep cycle battery. This would enable you to disconnect the factory “chassis” battery when towing, as the owners manual states, but still have power for the brake attendant.
To disconnect the factory battery, I would rather not have to open the hood and actually remove (or replace) the negative cable from the chassis battery, every time I hitch up or unhitch. For that function, I found a remote control battery disconnect switch, intended for boats. With a click of the remote fob, the chassis battery can be connected or disconnected. I have not installed this yet, as the poorly translated instructions are less than clear to me. May need a little experimenting with this, but if it works it would be pretty slick.
Here is the deep cycle battery installed and hooked up in the extra tray. There is a 15 amp fuse right near the positive connection, to protect the new circuit.
Then, with the help of my 17 year old, we fished the power lead into the cabin by going through the inner fender, into the driver door jamb,
and then through a factory hole and grommet under the driver door hinge, which is apparently there (along with several other unused grommets) for police upfitting.
This brings the battery connection into the driver footwell. The brake attendant will sit here during a tow, and operate the brake pedal. It will get power from the deep cycle battery, and we can use the same lead to connect a charger to the deep cycle battery as needed, when at your destination. The other black wire is the connection to the breakaway switch beneath the front bumper.
When these wires aren’t in use, they just tuck under the floor mat or the carpet itself. I used zip ties to route them and keep them clear of the foot parking brake. I finished off by cutting a notch in the factory grommet to allow room for the wires, and then covered the reinstalled grommet with a generous helping of clear silicone caulk for waterproofing.
Brake lights for the towed vehicle are imperative, of course. There are multiple ways to address this need.
1. You can hack into the towed vehicle’s wiring and use the signal from the 7 pin connector on the RV to activate the tail, stop, and turn light just like it was any trailer. This is what my parents did on the Subaru.
2. You can use magnetic tail, stop and turn combination lights which have a long cable to plug into the 7 pin connector on the RV. This would be similar to what you see used on towed, disabled cars sometimes.
3. With the magic of Bluetooth, there are now wireless options.
I settled on these lights, which are magnetic and use Bluetooth to communicate with the controller you see here, plugged into the 7 pin connector on the RV. They have tail, stop, and turn modes according to the signal from the RV connector. The controller gets its power from the RV 7 pin jack, it does not need charging.
The lights use a standard USB charger, and claim to have 100 hours of “standby” time. The hours they will last illuminating of course varies, but the instructions say you should bring them inside and plug them in each night when travelling, just to be sure they remain sufficiently charged. They have an LED power meter that illuminates when you turn them on, to indicate the percentage of charge.
We are going out West in October for 3 or 4 weeks. Though I wasn’t planning on towing the Suburban much (or at all), my youngest son is deferring his college acceptance for one year, due to the COVID mess. So, he’s going to go with us, and our oldest (now living in California) wants to fly to meet us. So, we can use the space to tour the four of us around. And, my son likes the idea of driving the Suburban some, so he can follow (or lead the way) if the Suburban is too big of a toad in the hillier parts of the trip.
We’ll takes some pics along the way and file a report!
If you pass through Colorado, feel free to look me up! We have a similar set up on our Wrangler, it was towed some before we bought it, but since I don’t have the RV half of the set up (or an RV for that matter), I should probably just remove it, it’s likely a fair amount of weight on the front.
It’s be a tossup if I’d want to do all that work myself to install this on the Suburban or pay someone to do it but then have to hope they don’t screw up the bumper! Although I guess Covid helps in making that decision as with many others, better to avoid people in general for non-essential stuff. Great write-up!
The tow plate itself is probably 75ish pounds, so maybe not worth the trouble to remove. They should have used red Loctite, so it might be a chore……the Wrangler is a very popular toad, so having that setup on there might even help at resale or trade-in time.
Why would you ever assume that we would ever sell it? 🙂 🙂 🙂
I actually didn’t think of that but you are probably correct. So stay on it shall! Thank you.
I think you have this all backwards; you should be towing the RV with the Suburban. 🙂
I know you’re a careful and conservative driver. But having a Sprinter, which already had to have auxiliary suspension components added to deal with its overweight issues pulling a 6,000 lb Suburban sounds a bit much. But then I’m hardly one to talk, given that I used to tow 7,000+ lbs of excavator and trailer with my ’66 F100 six cylinder and drum brakes.
Seriously, it sounds like it’s a bit much, but I guess it’s all within the realms of doable.
And yes, a cheap lead acid deep cycle battery was the right call for this application. I suspect the actual drain will be quite modest.
So how does the brake controller work with those Bluetooth lights? Does it have a device to put in the passenger compartment with a brake feed based on the brake signal in the 7 pin connector. Or do you have to make a Y connector to break out the brake feed?
That battery disconnect seems like it may not be up to the task. Does it have a stated amp rating? What size are the negative wires? From the picture they don’t look much larger than the voltage sense wire. That installation warning in red makes me think it can’t handle a lot of current, at least for a extended period of time. Of course with a modern car it isn’t like the starter runs for more than a second or two. At least it uses the standard manual disconnect so it can be connected that way if needed.
I’m also surprised that there isn’t a threaded hole for the factory clamp style hold down in the second battery tray. You will want to put it on that charger-maintainer from time to time in the off-season, or maybe consider an automatic charging relay so it is kept charged when you run the vehicle.
The cutting the hole in the bumper would be the scary part to me, but at least it is in a separate unpainted panel so it could be replaced separately if it didn’t turn out to your satisfaction.
Agreed. The battery disconnect does look pretty chincy. a heavier duty manual disconnect would be a better choice. A battery isolator between the primary and secondary battery will allow the alternator to keep both charged up in the off season. A ground wire from the -ve post of the second battery to the chassis is required for this.
I don’t like that disconnect either….I appreciate you all weighing in that it looks substandard. Backs up my suspicions, but I don’t have technical knowledge.
Well the brass portion is more or less the industry standard quick disconnect. Unscrew the green knob to break the circuit, though in this case it seems as though they have added an additional insulator so tightening the knob doesn’t make the circuit.
You can buy them with many different brands but they all seem to come from the same factory. Here it is at Harbor Freight.
https://www.harborfreight.com/battery-disconnect-switch-97853.html
Personally I’ve given up on the traditional diode based battery isolator. Today’s automatic charging relays are not much more expensive. They are a much easier install since it eliminates the voltage drop of the diodes so it works properly with modern charging systems.
I just installed a Blue Sea unit in my friend’s wheelchair lift equipped van that I put a second battery in. It connects the two large terminals if the system voltage rises over 13.6v for 30sec, or 13.0v for 2 minutes and disconnects if voltage drops below 12.35v for 10sec or 12.75v for 30sec. It also has a over voltage cutoff that separates the batteries if it detects overcharging to at least spare one of the batteries.
The Bluetooth lights are simply taking their cue from the 7 pin connector on the RV. So if the RV brake lights go on, the magnetic lights on the toad go on, and so forth.
The “Brake Buddy” sits in the floor of the driver seat, and has an arm that clamps to the brake pedal. It has an internal pendulum that activates the braking on the toad. You can adjust it for how much/how quickly it stomps the toad brakes in reaction to sensing that the Suburban is stopping (due to the RV braking).
So, neither the factory brake controller in the Suburban or the brake controller I installed in the RV have any role to play in this particular toad arrangement.
I didn’t expect the brake controller in the Sub to be involved but I sort of thought the one in the Sprinter would be. Is there a remote so you can apply only the towed vehicle’s brakes if you want to straighten the rig out.
Personally with big trailers I use the boost feature on my controller so the trailer leads the braking slightly. Normally I’ll use low setting for 3-5,000 towed weight and the high setting for larger loads.
I always like to see a clean installation of electrical accessories. I like to follow and secure to the factory harness rather than hide it away which makes it easier for someone else to trace if the need arises. It keeps the wires secure so they don’t rub on anything. An id tag at the power source to identify what it is always helps. One thing concerns me though is where the power wire passes through the metal holes such as behind the door hinge. What else could it be rubbing on inside the inner fender? Vibration will eventually wear through the insulation and hopefully blow the fuse rather than drain the battery or worse, heat up the wire and possibly cause a fire. Either way the brake attendant will lose power and you may not even know.
It’s good to see people taking on projects like this. The world needs more diy.
The Eastern Continental Divide swayed my decision to not purchase a Skoolie in NC to bring north to my part of VA. It had a 4 speed auto without a locking torque converter. If I didn’t burn up the trans on the ascent, I’d probably killed the brakes, and myself, on the descent. Combined with an unknown maintenance history, it was an estate sale and seller had no knowledge of vehicle history, I think I did right.
Even if you don’t use the tow set up now, this gives you options in the future.
You don’t want to flat tow any manual transmission unless you have a transfer case that has a neutral position. The problem is the transmission input shaft and the counter shaft are not turning and the counter shaft is what throws the lube around in the trans to keep everything lubricated. The main shaft will be spinning like crazy but all the gears are stationary because the counter shaft is held stationary thru the input shaft by the engine. The most vulnerable piece is the bearings or bushings that the tip of the mainshaft rides in at the rear if the input shaft. No lubrication, input shaft is stationary and at road speed the main shaft is probably spinning 2000 rpm at a minimum.
Last piece of advice, a battery isolator is a bad idea, you usually lose about 1 volt thru it. Can cause your secondary battery to be undercharged or depending on how things are wired it can cause your alternator to over charge your primary battery. You can accomplish the same thing using a high amperage continuous duty relay/solenoid and probably do it a lot cheaper.
Thanks for the information! I don’t know that I will install the battery isolator I purchased online. I don’t think it is a quality product. I’m leering of installing it in a pretty new/under warranty vehicle.
What you pictured above is a disconnect, not an isolator. An isolator is used to have the vehicle charge two batteries but keep their drains isolated. IE using something powered by the house battery won’t drain the vehicle battery or vice versa.
Yeah the old school diode based isolators don’t really work with modern rigs, you often can’t relocate the alternator’s voltage sensing location to after the isolator so both batteries end up undercharged, or the computer gets angry.
Automatic charging relays are the way to charge additional batteries, they have come down dramatically in price are really easy to install and are friendly with modern charging systems.
I should add, the old Ranger 4×4 MT that I had had instructions for flat towing in the owner’s manual. For it you were supposed to leave the transmission in a gear, put the transfer case in Neutral and lock the front hubs so that the front output which is below the oil level can sling the oil up to the rear output which was above the oil level.
Works as an isolator if it is wired properly.
Since I’m catching up on CC, I’ll note that the second battery tray dates back to the 87-99 GM-T400 platform where the second battery supplies 24V for diesel applications. my son’s 96 Suburban has a 350 V8 so there is a factory issue plastic storage box in place of battery #2.