Parts Required To Flat Tow A 2019 GMC 2500HD

Question:

Can you list the items I would need to flat tow my 2019 GMC 2500HD Denali with the Duramax diesel engine. I read one answer but it was toward a gas engine, and on the battery disconnect you mentioned specifically if you dont get a diesel or dual battery vehicle. But you did not expand on the diesel requirements.

asked by: Terry D

Expert Reply:

For flat towing the 2019 GMC 2500HD Denali Duramax 6.6L V8 diesel engine model Sierra you need to follow the prescribed towing procedures outlined in your Owner's Manual.

Only four-wheel drive vehicles with a two-speed transfer case that has a Neutral and a 4-low setting can be towed four wheels down. The negative battery cable must be disconnected and not touch the terminals. Also use of a shield mounted in front of vehicle grille could restrict airflow and cause damage to the transmission.

Parts you need include a base plate kit, a tow bar, safety cables, a lighting solution, a supplemental braking system, and most likely a high-low adapter.

For base plates, I recommend the Roadmaster Direct-Connect Base Plate Kit - Fixed Arms # RM-3180-2. These are designed specifically for heavy-duty applications and direct-connect brackets install onto your Ram 2500's frame to provide fixed attachment points for a motor-home-mounted tow bar.

The Roadmaster Nighthawk All Terrain, Non-Binding Tow Bar w/ LED Lights - RV Mount - 8K Item # RM-676 is an excellent, non-binding tow bar that features a self-aligning design, extra-long telescoping arms for better maneuverability, and integrated LED lights that illuminate with your RV tail lights for greater visibility. .

I do recommend adding the Tow Bar Cover # RM-055-3. This helps keep the unit free of dirt and road grime to ensure smooth operation as your trips start to add up.

A lighting solution that pairs well with the Nighthawk is the # RM-152. This diode kit connects your towed vehicle's turn signals, running lights and brake signals to your motorhome's. Diodes prevent electrical feedback and protect both vehicles’ electrical systems. After installing the diodes and the 6-Way connector included with Nighthawk's kit to your Denali, your motor home's 7-Way will connect right to it.

For a supplemental braking system, I recommend the SMI Air Force One Supplemental Braking System for Motor Homes with Air Brakes # SM99243. This is great proportional system that activates the Sierra's brakes at the same time and with the same intensity that you apply to them in your RV. The Stop Light Switch # RM-751463 is also needed to ensure proper operation of the system.

For diesel engines like your Duramax, we can't use a battery disconnect. That means you will have to disconnect the battery manually. While that may be inconvenient, using a battery disconnect could cause your vehicle damage and potentially be a vehicle fire risk. Diesel engine starters require a lot more power than gas engines and the higher current could damage a battery disconnect, your engine starter, and the potential for fire.