Sway Control - Who Saved the Day?
Hello, folks. Been an RV'er for a little over two years, and had an experience about seven months ago that prompted me to join this forum just to get your thoughts on it. I grew up towing EVERYTHING...
Forum Discussion
LOL Ben you said what I was thinking, these complicated features work great until they don't, the complexity of vehicles is rapidly outstripping the ability of dealer techs to repair them.
My personal preference is to have the TT brakes lead the TV brakes, mainly to manage the Hensley "bump". I would agree that controllers that use a hydraulic pressure sensor to vary brake voltage are not as good as accelerometer-based units, regardless of cost.
Two scenarios: First, if I downshift the transmission to provide engine braking on a downhill grade, I only need to press the pedal lightly to wake up the P2, then it will sense I am slowing down and apply the TT brakes. I don't want to have to apply the TV brakes with enough pressure top activate the TT brakes, that's the whole reason for downshifting the transmission.
Second, if I stomp on the TV brakes on ice, I will build great line pressure but the ABS will modulate pressure to the wheels to avoid a skid. In this scenario, the TT wheels will be locked up based on the pedal pressure I am exerting.
Hopefully an OEM controller would be integrated enough to override its basic line pressure input based on ABS and transmission inputs. It would also seem to me that the OEMs that market some form of "trailer sway control" or "stability" must be using some type of accelerometer to sense lateral movement, along with input from the steering angle sensor, that would be indicative of sway and apply the TT brakes.
Interesting side conversation while we wait for the OP to check his trailer to see if he has some type of electronic sway control installed on it. I'll need to do more research on these controllers when I am ready to buy a truck, it's not a given that one would be better than P2.
My personal preference is to have the TT brakes lead the TV brakes, mainly to manage the Hensley "bump". I would agree that controllers that use a hydraulic pressure sensor to vary brake voltage are not as good as accelerometer-based units, regardless of cost.
Two scenarios: First, if I downshift the transmission to provide engine braking on a downhill grade, I only need to press the pedal lightly to wake up the P2, then it will sense I am slowing down and apply the TT brakes. I don't want to have to apply the TV brakes with enough pressure top activate the TT brakes, that's the whole reason for downshifting the transmission.
Second, if I stomp on the TV brakes on ice, I will build great line pressure but the ABS will modulate pressure to the wheels to avoid a skid. In this scenario, the TT wheels will be locked up based on the pedal pressure I am exerting.
Hopefully an OEM controller would be integrated enough to override its basic line pressure input based on ABS and transmission inputs. It would also seem to me that the OEMs that market some form of "trailer sway control" or "stability" must be using some type of accelerometer to sense lateral movement, along with input from the steering angle sensor, that would be indicative of sway and apply the TT brakes.
Interesting side conversation while we wait for the OP to check his trailer to see if he has some type of electronic sway control installed on it. I'll need to do more research on these controllers when I am ready to buy a truck, it's not a given that one would be better than P2.
4bamayoungs wrote:BurbMan wrote:
Question: did you buy your trailer new or used? The reason I ask is that if used, the previous owner may have had an electronic sway control installed. These are motion-sensing gyro devices that will activate the trailer brakes when a sway condition is detected.
Link to Dexter Sway control
Link to Hayes Electronic Sway Control
If you felt like the trailer braes activated, they very well may have. The groaning you heard would have been weight distributing hitch straightening out suddenly in response to the trailer brakes coming on.
If you bought the rig used, the previous owner may have had one of these installed and that info wasn't passed along as part of the resale to you.
Interesting. I bought it used from a dealer. The trailer is at a storage lot, but I’ll make a trip out there and look around.
