When braking how much trailer weight transfers to TV ?

[SilverCabin]

When setting up a WD Hitch, most vehicle manufacturers recommend only bringing the TV steer axle back to 50% of where it was before applying the hitch weight. This is so that in an emergency stop, the forward weight transfer doesn't break the TV drive axle free causing a jackknife. Keep this in mind when setting up your hitch.

Randy

[BayouBiker]

The 50% guidance is to reduce risk of a jackknife but it is due to oversteer from rear tire slip in hard cornering. Hard braking and even sudden deceleration while cornering and on steep downgrades increases the effect. However, the 50% guidance applies when the vehicle is towing near trailer weight and especially tongue weight limits. If your combination is well below both limits additional load return is often optimal for ride and handling quality, and sway damping.

[ROBERT CROSS]

Originally Posted by SilverCabin

When setting up a WD Hitch, most vehicle manufacturers recommend only bringing the TV steer axle back to 50% of where it was before applying the hitch weight. This is so that in an emergency stop, the forward weight transfer doesn't break the TV drive axle free causing a jackknife. Keep this in mind when setting up your hitch.

Randy

"Most"?
If that's true what has changed? Are P/U's all that different?
Is it the design or the capability of the TV?
How does a lighter steering axle 'improve' towing stability?
I'm 100lb light under most loading, if I add 75lb I can definitely notice the difference, is it unsafe? I'm not willing to test it. I'll stay at the FAL I'm at.
WMMV

Oh BTW...under braking is it the added 'weight' or the added force caused by the weight that's worrying folks?
Seems proper lash-up and a working brake system would mediate any concerns there.

Bob
🇺🇸

[Collyn]

Are some not overlooking that sequence was in Australia - where our gravity is upside down?

Re: Oh BTW...under braking is it the added 'weight' or the added force caused by the weight that's worrying folks?

Weight is a force!
Collyn

[BayouBiker]

I think many people have heard that since the trailer has its own brakes and they are applied proportionately with the controller, you don't need to worry about the vehicle brake size and capacity. But they notice stopping distances are extended and they hear stories of vehicle brakes overheating on steep grades and something doesn't meet the smell test.

Well, once again Newton does not steer you wrong, the physics can't be cheated, and indeed the vehicle handles a significant percentage of required trailer stopping force, generally 15-30% depending on controller gain and trailer loading.

If you just use the trailer brakes manually alone to slow the combination, you just move the issue as the trailer brakes now heat up excessively and are at risk of fade. Best is to distribute the load so all brakes can dissipate the heat energy and apply them intermittently to give them a chance to cool some. If your brakes are marginal for the job and you find yourself in an unfortunate situation where you must use the brakes more than 20-25% of the time, slow down to reduce the energy load, at least then they will not overheat.

If your vehicle brakes are close to capacity, get some heavy duty towing and hauling brake pads rated for 700 degrees vs. the standard 450 degrees. These can handle over twice the energy dissipation rate without fade.

As a tip, if your brakes are very hot, when you stop, don't stay still with the brakes firmly depressed, instead edge forward slowly to allow heat to dissipate from the rotor evenly. Uneven heat will harden parts of the rotors and they will wear unevenly. Soon the brakes will stop unevenly as if they are warped.

[SYC2Vette]

Originally Posted by BayouBiker

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If your vehicle brakes are close to capacity, get some heavy duty towing and hauling brake pads rated for 700 degrees vs. the standard 450 degrees. These can handle over twice the energy dissipation rate without fade.

As a tip, if your brakes are very hot, when you stop, don't stay still with the brakes firmly depressed, instead edge forward slowly to allow heat to dissipate from the rotor evenly. Uneven heat will harden parts of the rotors and they will wear unevenly. Soon the brakes will stop unevenly as if they are warped.

Excellent information/advice. Before I changed out my connector and receptacle, we had an incident in Colorado on our first trip where without realizing it, we had no trailer braking and after a very long descent with multiple switchbacks, we had seriously overheated our TV brakes and faded to the point where I had difficulty coming to a stop at a turnout. Took about 20 minutes to cool down, no apparent long term affect on braking. Yes, before anyone says it, a 3/4T truck would have likely not faded the brakes with our 5,000 lb trailer.