Can I Upgrade from 6,000 lbs Axles to 8,000 lbs Axles on 5th Wheel Toy Hauler?

Question:

I’m considering upgrading axles from Dexter 6k torsion to 8k on a 5th wheel toy hauler. I’m not interested in doing this to load the trailer heavier, only hoping to increase braking capacity and safety. When loaded I’m barely below the rating of the current axles and for example, I believe it would be safer if when loaded I were 7k below the limit of my axles vs 1k. Thanks for your time.

asked by: Mark M

Expert Reply:

As someone who has knowingly overloaded a trailer out of necessity, I completely understand your thought process here, but I think I have a better option for you that will save you both time and money in upgrading to electric-over-hydraulic discs brakes on your existing 6K axles.

I wouldn't install 8K axles for two reasons, suspension stiffness and drum size. The suspension on an 8K axle will be significantly stiffer than a 6K axle and this will create more jarring and a rougher ride for your trailer and all of the components in your trailer. Your appliances, cabinets and electronics will not appreciate this. Also, the 8K drums are bigger and may create some clearance issues in your wheel wells. We experienced this personally at our shop on a flatbed trailer. The 8K hubs pushed the tires out almost 1-1/2 inch further on each side causing them to hit the outer edge of the fender.

We've done several electric to electric-over-hydraulic disc brake conversions on 5th wheel trailers and they dramatically improve the braking capacity/response and create a safer feel when towing. Disc brakes are much more efficient at braking than drum brakes.

To do this, I highly recommend installing the HydraStar Disc Brake Actuator Kit, # HBA16-252-82, which comes with everything you will need for this installation including the electric-over-hydraulic actuator, brake lines and hardware.

For disc brakes, I recommend either the Kodiak Disc Brake Kit, # K2HR526D, if you want to keep your 6 bolt lug nut pattern, but if you want to upgrade to the 8 bolt pattern, then I'd actually go with the HydraStar Complete Disc Brake Conversion Kit, # HSE7K-T1. The only real advantage to moving up in bolt pattern is the ability to use larger wheels with higher capacity trailer tires.

I attached a few installation videos for the Hydrastar actuator kit and a disc brake installation video.

Finally, if you want to pick up some bearing grease while you are at it, I'd go with marine grease, # L54FR, because it does a better job of minimizing the impact of water that might find its way in from a bad grease seal or missing dust cap.