Setting the right gain value in Trailer Brake Controller (TBC)

[kavm]

I am completely new to towing. Will be pulling a 21' fifth wheel camper on Monday. I know where the Trailer Brake Controller is and how to adjust the value.... But, I am not sure how to determine what value I need to set. Can anyone share a link or other helpful insight...

I understand that the trailer brakes should come on just a fraction before the truck brakes but how to find the gain value that will do that. I was looking the YouTube videos that explain stuff, but did not find any...

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[Bryan Simon]

That trailer probably has some weight to it, so this is what I would do.
set it in the middle and go from there.
You don’t really want it dragging you to a stop before you’re ready to stop, but kinda needs to bring you down safely without locking up.

I have not yet bothered to do anything with mine yet as it has recently been installed (supposed to come with the truck).

in my older trucks, I would set it so I could feel it helping, but not taking over..
I don’t tow as much as I used to, but wanted the controller just in case I do have to drag something around.

another method is to locate a large empty lot and experiment with it there with the trailer hooked up.

It may come down to a personal preference.

 

[Sundancer330]

Go through trailer settings on the dash to pick the type of trailer you have then follow these steps from the manual, a large parking lot at a school or church works.

1. Hook up the trailer and make the electrical connections according to the trailer manufacturer's instructions.

Note: Select default mode if the trailer has surge brakes, or no brakes at all. The system has no effect on the braking performance of the trailer in either of these cases.
Note: If a trailer is connected by a four-pin connector, the trailer braking function will not be supported.

1. When you plug in a trailer with electric or electric-over-hydraulic brakes, a message confirming connection appears in the information display.

1. Use the gain adjustment to find the desired starting point. A gain setting of 6.0 is a good starting point for heavier loads.

Note: Use the following steps to adjust the gain setting whenever road, weather and trailer, or vehicle loading conditions, change from when you initially set the gain.

1. In a traffic-free environment, tow the trailer on a dry, level surface and squeeze the manual control lever completely.

1. If the trailer wheels lock up, indicated by squealing tires, reduce the gain setting. If the trailer wheels turn freely, increase the gain setting. Repeat Steps 5 and 6 until the gain setting is at a point just below trailer wheel lock-up. If towing a heavier trailer, trailer wheel lock-up may not be attainable even with the maximum gain setting of 10.

Note: Only perform this procedure at speeds of approximately 20–25 mph (30–40 km/h).
Note: The trailer brake controller reduces output at vehicle speeds below 11 mph (18 km/h) so that trailer and vehicle braking is not jerky or harsh. This feature is only available when applying the brakes using your vehicle's brake pedal, not the controller.
Note: Your vehicle's brake system and the trailer brake system work independently of each other. Changing the gain setting on the controller does not affect the operation of your vehicle's brakes whether you attach a trailer or not.
Note: With the proper electrical connection, pressing your vehicle brake pedal or using the manual control lever illuminates both trailer and vehicle brake lamps.
Note: When you switch the engine off, the controller output is disabled and the display and module shut down. The controller module and display turn on when you switch the ignition on.
Adjusting the Trailer Brake Gain

A Increase or decrease the amount of gain in set increments. B Slide the control to engage the trailer brakes.

Note: Adjust gain setting before using the trailer brake controller for the first time.
Note: The gain should be set to provide the maximum trailer braking assistance while making sure the trailer wheels do not lock when using the brakes. Locked trailer wheels may lead to trailer instability.
Note: Setting adjustments are saved when a trailer profile is selected.

 

[kavm]

Thank you so so much! Very helpful.

 

[daemonic3]

My original dealer said for a Ford start the first guess as GVWR/1000 for gain, and then adjust from there (I have no idea if this was good advice but I had no other experience). So for a 7995# GVWR start with 8.0 and adjust from there. My last trailer felt fine, I tried adjusting it a little both ways and didn't notice much difference so I left it 8.0 for 3 years.

New trailer is 7495# GVWR so I started with 7.5 and drove off. First few stops at lights felt a little wonky/jerky so I bumped it down. Bumped it down one more time to 6.5 and it feels smooth, went all the way down 7.2k feet of summit to sea level with that setting and nothing burnt so I'm keeping it.

Point is, each trailer may vary but pick a decent first guess and do the adjustments in a safe area your first time using that above procedure in previous post.

Have fun!

 

[chrisp993]

Sundancer330 gave an excellent overview, I'd only add that you'll need to change (reduce) the gain in slippery/rainy conditions since my experience is that the trailer tires will have a tendency to lock up (no ABS!) if you keep the gain at the same level as dry roads ...

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