Parts Needed to Tow a 5000-lbs Trailer with 2009 Lexus GX 470
Question:
Hi - I am looking to install a setup on my 2009 Lexus GX470 to tow a car trailer that will weigh up to 5000 lbs. My GX has the factory tow package on it, but not a receiver, so I need to add one. It also has the factory air suspension. It has about 140,000 miles on it. The suspension is in good shape and the truck has been well maintained. That being said, the rear air bags are original, so I plan to install new ones prior to towing. I think I want a sway-control hitch due to the relatively short wheelbase, but beyond that I do not know what I need to install on the truck to safely and comfortably tow up to 5,000 lbs. Can you point me in the right direction as to what products I need to install. Is there any additional maintenance or additions that should be made to the rear suspension? Thanks,
asked by: Sean M
Expert Reply:
It sounds like you've already got a wiring harness installed potentially, so starting with a hitch I recommend using the Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # 13445, which is a confirmed fit on your 2009 Lexus GX 470. In my experience, Curt hitches have a thicker powder coating that helps protect the hitch from scratches and dings, so it's going to be less susceptible to corrosion over the long run. If your Lexus GX 470 doesn't have a wiring harness but has the tow package wiring present then you can simply add the Hopkins # HM43374 to give you both 4 way and 7 way plugs for your trailer wiring harness.
If your trailer has brakes on it, you'll need a brake controller; for that I recommend using the Tekonsha Prodigy P2 # 90885 and plug in adapter # 3040-P. The Prodigy P2 provides you with proportional braking for your trailer that is simple to use, and Tekonsha controllers are extremely reliable, so this is a great choice. The plug in adapter # 3040-P allows you to install the controller easily using the factory installed plug under the dash, so it's the best way to install a brake controller.
Since you've already got a factory air suspension system, adding another suspension enhancement might be a bit overkill. I'll also add that there isn't an aftermarket air bag system available for your vehicle so you would be limited to a jounce style enhancement like the Timbren # TTORSEQ, which would be the only option available. This is a progressive compression type system, so it gets stiffer as more weight is loaded on it and will do a good job of helping absorb road shock and reduce body roll when cornering.
When it comes to weight distribution with sway control, we typically recommend that any time your trailer weighs more than 50% of the weight of the vehicle and you'll want to choose the best weight distribution system based off of the tongue weight of the trailer. Since you've got a 5000-lbs GVWR trailer, your likely tongue weight will be between 500-lbs and 750-lbs, based off the recommended 10-15% of the GVWR. You can get weight distribution and sway control built into one weight distribution system with the Curt TruTrack Weight Distribution System w/ Sway Control - Trunnion - 8,000 lbs GTW, 800 lbs TW # C17499, which would be my recommendation for a flatbed style car trailer and this will do a great job for you.
The last thing you would need is a ball mount and hitch ball; the size of the hitch ball you'll need depends on the size of the trailer coupler. I would also recommend measuring to determine if you'll need a rise/drop ball mount, and I've linked a helpful article that outlines how you can do that. You might be able to get away with a complete kit like the etrailer Ball Mount Kit # 989900, which comes with 2 ball mounts with varying rise/drop, 2 hitch balls (1-7/8" and 2"), hitch pin, clip and carrying bag. I've also linked our entire selection of ball mounts and hitch balls that you can look through to pick something specifically for your setup.
There isn't any additional maintenance that you'd need to do that you wouldn't already be doing to the vehicle, and it sounds like you've kept this rig well maintained, so I think you'll be in good shape there.
In addition to the above mentioned linked, there are also some review and installation videos of the parts I've mentioned that you can have a look at, as well .

Products Referenced in This Question
Tekonsha Plug-In Wiring Adapter for Electric Brake Controllers - Toyota and Lexus
- Accessories and Parts
- Trailer Brake Controller
- Wiring Adapter
- Plugs into Brake Controller
- Vehicle Specific
- Tekonsha
more information >
Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Electric over Hydraulic
- Splice-In
- Under-Dash Box
- Under-Dash
- Up to 4 Axles
- LED Display
- Single Trailer Only
- Tekonsha
more information >
etrailer Ball Mount Kit for 2" Hitches - 7,500 lbs
- Trailer Hitch Ball Mount
- Fixed Ball Mount
- Two Balls
- 1-7/8 Inch Ball
- 2 Inch Ball
- Steel Shank - Gloss Black
- Drop - 2 Inch
- Drop - 4 Inch
- Rise - 1 Inch
- Rise - 3 Inch
- Fits 2 Inch Hitch
- 7500 lbs GTW
- etrailer
more information >
Curt TruTrack Weight Distribution System w/ Sway Control - Trunnion - 8,000 lbs GTW, 800 lbs TW
- Weight Distribution Hitch
- WD With Sway Control
- Some Sway
- Includes Shank
- Electric Brake Compatible
- Surge Brake Compatible
- Fits 2 Inch Hitch
- Allows Backing Up
- 600 lbs
- 700 lbs
- CURT
more information >
Hopkins Plug-In Simple Vehicle Wiring Harness for Factory Tow Package - 7-Way and 4-Flat Connectors
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- Factory Tow Package
- 7 Round - Blade
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- Hopkins
more information >
Timbren Rear Suspension Enhancement System
- Vehicle Suspension
- Towing/Load Leveling
- Bump Stops
- Extra Heavy Duty
- Rear Axle Suspension Enhancement
- Timbren
more information >
Product Page this Question was Asked From
Curt Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Trailer Hitch
- Custom Fit Hitch
- Class III
- 500 lbs TW
- 5000 lbs GTW
- 5500 lbs WD GTW
- 2 Inch Hitch
- 500 lbs WD TW
- Visible Cross Tube
- CURT
more information >
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