HEAVY TOWING - SAFELY
By: John Holmes`

It seems that each year the motorhomes get larger and heavier. Along with that, the "dinghies" grow in size. This all adds up to something approaching an 18-wheeler in length and weight. If you're towing a heavy SUV or pickup behind your rig you want to be sure you're doing it safely.

The first thing to check is that you aren't exceeding the Gross Combined Weight Rating (GCWR) of your coach.... the loaded weight of the towing vehicle combined with the loaded weight of the towed vehicle. Check your towing vehicle and chassis manufacturers recommendations for towing, hitch load and braking capacities. Once you know that you're not exceeding the manufacturer's parameters, the next thing you need to examine is the tow bar/hitch system.

I guess I fall into that category of "bigger is better" when it comes to motorhomes and the stuff that follows them down the road. When we bought our rig we specified that it be capable of towing our show cars in an enclosed trailer. This means our 40' coach at times drags a 10,000 pound, 24' car hauler behind it. We also go to diesel truck shows and wanted to be able to flat tow, not only our SUV, but also our truck. (Whoever said we try to get away from it all just didn't understand...we take it all with us!)

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` Flat towing the truck gets us into the heavy duty category when it comes to tow bars, hitches, safety cables/chains, base plates and towed vehicle supplemental braking systems. Our little Jeep isn't too bad, but our Dodge diesel truck weighs over 7100 lbs empty. We wanted something that could safely yank our pickup down the road when the occasion arose.

Blue Ox is the only company that has a 10,000 lb rated system. We selected their Aventa II, which is a Class IV tow bar for use on vehicles up to 10,000 lbs. That matches the rating of the hitch on our motorhome. The Aventa II is an easy fold-away tow bar that mounts and stores on the back of the RV. It's self-aligning with quick disconnect hookup pins. The bar is heavy duty steel and comes with a limited lifetime warranty. The same goes for the Blue Ox base plates.

Once we had all of the necessary pieces and parts, it was installation time. I'll describe setting up our Jeep as a dinghy since an SUV is more typical of what you see dutifully following RVs down the highway.

Remember, tow only those vehicles that are designed to be flat-towed. Check your owner's manual for recreational towing procedures. For example, Blue Ox's instructions said," The transmission should be placed in neutral when towing". That's not always the case. Many four wheel drives specify that the transmission should be in Park, with the transfer case in neutral, when towing. That's why we use our old Jeep because, like most four wheel drives, it has a transfer case that allows you to completely disconnect the driveline from the engine/transmission. No worries about cooking expensive components.

My first step was to measure the height from the ground to the RV's hitch and then from the ground to just below the Jeep's bumper where the Blue Ox base plate would connect to the tow bar. This is CRITICAL! You only have a four inch swing between absolute level to the maximum drop the tow bar can be below the RV's hitch level and the point of connection with the towed vehicle's base plate. NEVER operate your rig with the towed vehicle connection ABOVE the level of the hitch on the motorhome. Do that and you'll pole-vault that puppy right into the back of your pusher!

OK, now that I know everything is compatible, it's on to the installation of the base plate on the Jeep. The instructions were good and all of the parts fit. There was a good exploded view/diagram of the base plate and associated components. There were also some good pictures that help so much when you launch into a project like this. I like seeing what it's supposed to look like when you get all through...as you sit there with pieces, parts, nuts and bolts scattered all around you.

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` In addition to some differences in various models, there's lots of options that you or many not need to deal with like fog lights, tow hooks, etc., but basically you have to remove the front bumper and a few other minor things to get to the frame where the base plate will be attached. Our Jeep had a front skid plate that had to come off and which we decided not to put back on since modifications were necessary for re-attachment (this Cherokee no longer scouts out pioneer trails). It's very important that you install a permanent chain/cable between the convenience links on the base plate and the dinghy's frame, unless your safety cables/chains are going to be hooked directly to the frame. I only recommend that if you enjoy turning yourself upside down and getting greasy each time you hook up.

OK, now it's time to check out the hook-up between the tower and the towee. The Aventa II slipped right into the coach's receiver. Again, the instructions were good with lots of illustrations. I used the first of the two holes to pin the hitch so that I would have the maximum distance between the coach and the Jeep for clearance in tight turns. It also gives you a little more room between the RV and the tow bar when its folded in the storage position. By the way, I suggest you install a locking pin on this great unit instead of the regular hitch pin arrangement that comes with the kit. This way it won't grow legs while you're parked.

Now move the vehicle to be towed, in a straight line and on a level surface, up behind the towing RV. I found it was easy to judge the hookup distance by letting the tow bar ends rest on the ground (do NOT extend the legs) straight out behind the motorhome and then drive your dinghy up to within a few inches of the tow bar. Be sure to set the brake so you don't run over yourself! Now you can easily extend each leg to attach them to the tabs on the base plate. Be sure to correctly lock the quick pin assembly in the ends of the attachment pins (tow bar to base plate tabs) by rotating the ring towards the nose of the pin .

You'll note that the Aventa II has spring loaded locking handles. When they're up they're locked...down they're unlocked. It's recommended that you either move the dinghy or the RV enough to extend and lock the two legs in the locked towing position. Be sure to check that both locking handles are in the up position. Driving off and letting the handles lock is very hard on the towing system and could be hazardous if one of the legs doesn't lock correctly.

Now we get to the safety cables/chains, that are required by law, between the motorhome and the dinghy. Remember the old saying about the "weakest link in the chain". You've got a class IV, 10,000 lb tow bar, so you've got to have at least that capacity on all other components related to the towing system.

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` Of course, the main function of the safety cable is to prevent your dinghy from wiping out a small shopping mall should the tow bar become disconnected. Be sure to cross the cables under the receiver area! That'll prevent the tow bar from dropping to the pavement in the event of a failure. Don't let the cables drag on the ground and don't wrap them around the tow bar leg's rubber boots (it'll chew'em up). However, you should wrap each cable, once or twice, around their respective tow bar leg. The cable kit comes with a really good illustration on how it all should go together.

Blue Ox has 5000 lb and 10,000 lb safety cable kits in five and six foot lengths. Be sure to get the 10,000 lb model if you're towing a heavy vehicle. As a side note, their hooks have a rubber keeper to prevent accidental disconnect....different. I was used to spring clips, but they work great. Let me say again, you should have permanent chains/cables connecting the convenience loops on the base plate to the vehicle's frame.

Also required by law are lights on the vehicle being towed. You can either use the popular magnetic add-on light kits or wire into the towed vehicle's lighting system. I used a 7 pin to 4 pin adapter/plug that came with our trucks to connect the magnetic light wiring harness' 4 pin plug to the 7 pin trailer socket on the coach. These accessories can be found at most RV/auto parts stores if you need them.

Caution: If you decide to tap into the towed vehicles wiring to operate the rear lights, be sure to use the proper diode/wiring kits for your specific dinghy. Modern cars and motorhomes use lots of solid-state devices that will commit suicide in a heartbeat if subjected to stray unwanted voltages. Electrical isolation of various circuits is essential, not only between your coach and the dinghy, but also within each vehicle. Blue Ox can also help you with these goodies.

Now that we've got everything hooked together we're almost ready to get on down the road. Just remember, NEVER BACK UP! Your towed dinghy isn't a trailer. It's got front wheels that turn, which means that you can have your RV and the dinghy at 90 degree angles of one another almost instantly.

One more thing. Some states require that the towed vehicle have a braking system that operates in conjunction with the towing vehicle. These regulations originated from trailer requirements, but can be interpreted to mean anything towed. Even if you don't drive in those states, it's a good idea to use such a device for your own safety and to reduce the wear and tear on your RV. Blue Ox just happens to make such a gadget. It's called the Apollo Braking System.

Your coach's brakes were designed to stop your unit safely, but when the weight of a towed vehicle is added, brakes can become overburdened. Blue Ox developed the Apollo to fill this very important need for the safe operation of an RV and a towed vehicle. The Apollo is light weight, very easy to operate and can quickly be transferred from one vehicle to another. It installs in about three minutes and requires no electrical connections, mechanical connections or alterations to the motorhome. It even avoids unwanted braking on bumpy roads, bridges and railroad tracks.

Installation of the Apollo is fairly simple, but this is the one area I felt the instructions could have been better. You know that old expression, "Some assembly required". A picture/diagram of the correct setup in a vehicle would have been nice. Also there were a couple of pieces in the kit that weren't addressed or identified on the instruction sheet, although it was fairly evident how they should be used.

Our old Jeep, unlike modern models, didn't have a 12 volt power receptacle that remained on with the ignition key in the off position (just a cigarette lighter that worked only with the switch on). A quick trip to Wal-Mart's auto accessories section produced an accessory receptacle kit complete with wiring and under-dash mounting bracket. It took only a few minutes to mount the unit and tap into a "battery" (not switched) connection on the fuse panel.

Be sure to take the time to set up the Apollo so it functions correctly. Sensitivity and air pressure are easily adjusted to individual needs. The design affords a wide range of adjustment for the seat-to-brake pedal distance as well as conforming to various seat mounting configurations. You want the system to brake the dinghy when necessary, but you sure don't want it to cause the brakes to drag while you're heading for your favorite camping spot.

An important accessory for the Apollo is the break-away kit. If your dinghy should ever come loose from the RV, it could ruin your whole day! A recent letter to the editor of a popular motorhome magazine told of an incident exactly like that. Panic set in when the driver saw the towed vehicle missing. However, after driving back a couple of miles back down the road just traveled, there sat the dinghy, on the shoulder, with the brakes firmly applied. There was no damage and nobody hurt.

This kit is a simple pull switch just like the ones on trailers, but instead of applying battery voltage to the trailer brakes, this signals the Apollo to slam on the dinghy's brakes. Again, I felt the instructions/illustrations could have been a little better. I think the company assumes that an experienced installer is always going to do this when in reality it's often the RV owner. I strongly recommend the kit, it's inexpensive insurance.

Blue Ox has also come out with a really neat gadget called the Wireless Remote Dash Light Indicator. That's a big name for a tiny device that lets you know if the Apollo is operating your dinghy's brakes correctly. When the brakes lights on the towed vehicle go on, it lights a red indicator on the dash of the towing vehicle. The little transmitter plugs into the 12 volt accessory receptacle in the dinghy and has one wire that attaches to the cold side of the brake light switch. In the coach, you just plug in the receiver. Each unit can be mounted in a convenient location with adhesive hook and loop pieces furnished with the kit.

The instructions were good, accompanied by appropriate diagrams, with one exception. I disagree with the installation step that states: "...crimp the male adapter onto the brake signal wire and crimp the female adapter onto the transmitter signal wire." Using the bullet connectors in the kit allows you to disconnect the transmitter from the towed vehicle when it isn't being used as an RV dinghy. It also gives you the flexibility of using the device in multiple vehicles.

My problem with that statement is that if the male adapter/connector is on the brake light wire it'll be "hot" whenever you're stepping on the brake. This provides the possibility of shorting the tip of the male connector to ground on surrounding metal. If you reverse this and crimp the female on the brake light lead there's no exposed tip that could blow a fuse. Just a suggestion.

We've pretty well covered the getting going....how about coming to a stop and unhooking? First, park in a straight line on a level spot, then set your parking brake. Next unplug the Apollo and drain its air system. This is EXTREMELY IMPORTANT. Failure to do so may cause damage to your vehicle or it could give you a sub orbital ride into the next county. Now you can remove the Apollo from the front floor of the dinghy and store it in the trunk area.

Next comes the tow bar. Unplug the lighting and safety cables. Then disengage each leg of the tow bar by pulling the quick pins that hold them to the base plate. This may require releasing tension by pushing down on the locking handles. After completely disconnecting the tow bar, compress each leg to the detent position. With the legs together, swing them up and into the locked, stowed position. You'll find that, when stored, the Aventa II extends only slightly farther behind your coach than the rear ladder. This Blue Ox System is really slick looking plus it provides a heavy duty towing package for anything just short of a Sherman tank.

Just after getting everything installed, we took off on a trip of about 1000 miles. The Jeep towed like a dream...no sway...no problems. Hooking and unhooking was a snap. The Apollo worked perfectly. I didn't change the factory settings and those seemed to be right on the money for that vehicle. The instructions talked about feeling the "tug" at the motorhome when it was working correctly. Well, our 32,000 diesel pusher is a bit much for our little Cherokee "tug", but at slow speeds when the transmission retarder isn't working, and you're just using the air brakes, you could tell the two vehicles were braking together in a coordinated fashion. It's much like the way you set trailer brakes to work together with your truck.