Trailer hitch disengaged from ball

Kevin@7

I've owned my tab400 for a bit more than 4 years now and I never had the hitch come off the ball until recently.  Everything was hooked up as required and I was going into the storage yard which has a steep entry way which I hit at just the right speed and it found the right frequency.  That was enough to disengage where it activated my e-brake and fell on the chains.  Other than bending the chain car attachment and some minor scratches everything was ok.  I was lucky there wasn't more damage and it wasn't too much work to get it back on.   I was also fortunate that it happened with no traffic behind me.

Just a reinforcement to pass along that there is a very good reason for all the safety features when towing and nothing should be bypassed....even for short distances.  It could have been much worse lets say I was going fast or on a hill.  If you hit just the right frequency on some of these roads that may be just enough to have that happen.  I hate to think of this happening on the highway when your e-brake actuates and by the time you figure out what's happening you're trailer is locked up.  Makes it hard to get over to the shoulder.  As an FYI the e-brake cable release is keyed so don't try to jam it thinking it needs special tools to re-engage.  It can be done with hand force but you need to orient it right.  A bit of a blind operation.

I've been towing trailers for a number of years and there have been many of these minor things that keep you from taking it completely for granted.  I've been thankful that nothing has been severe but it could have been in at least 2 cases (non tab related).  Learn all the recommendations from the experts and realize they are all there for good reason.  Ie...Follow the guidelines for tow vehicle size, tongue weight, trailer weight distribution and positioning, use the right trailer tires, don't go too fast, etc.

ScottG

Interesting. Another owner reported a similar incident just a few months ago.

Marceline

First, I'm glad to hear that you and the T@B are OK.

I really don't think that it's possible for the coupler to disengage unless the coupler wasn't engaged properly in the first place or there was no safety pin. I don't think that it's possible for the coupler to open just because you were going the "right speed and it found the right frequency"

I say this as someone who's had the misfortune of dropping a loaded boat trailer on a multilane freeway going through a major metro area. In that case, it was an older trailer, and it turned out that there was enough corrosion in the coupler that the fork didn't drop when I opened the coupler, so when I closed and pinned the latch the fork was above the ball. Miraculously, I escaped pretty much unscathed, but it was a real wake up call. 

Ever since then, I physically check to be sure that the coupler is properly engaged. I use my hand, which I know is stupid, but it's probably better to use a mirror or crank the jack back up until you're lifting your bumper. I hitch up, drive 1/4-1/2 mile, stop, then walk around the trailer again. 

I've seen a fair amount of comments here and on other T@B forums from people who have been using a claw hammer to open or close the latch on their coupler. I suspect that people are damaging the coupler mechanism. (not saying that @Kevin@7 has been doing that, but mentioning it here since I've seen a lot of it over the years)

Kevin@7

I guess there is always the possibility it wasn't fully engaged but the pin and latch were fully seated when I observed post event.  There is that feature that prevents the latch from fully engaging unless it is seated correctly.  I'll check if anything was possibly damaged....maybe worn.  I'm always careful in those situations where you can't get the latch disengaged due to that all too familiar situation when you end up on un-even ground at a campsite.  Frustrating but I'll only lightly tap with a hammer and then resort to finding ways of easing the pressure by locking the trailer wheels and moving the tow vehicle just a bit.  That usually does the trick and much better than hard blows to the hitch which I've seen some do.

Kevin@7

Thanks @ScottG for the similar incident link.  As I was reading it could be the exact same situation as I was going up an driveway type incline which could have been enough to hit the tongue jack.  It was cranked up but I can imagine at some point it could still hit.  I did notice a big bounce which on the down stroke could have hit the tongue jack and put some serious force on the connection.

qhumberd

Wondering if with use the locking mechanism could loosen. Does this system have any adjustment range? Also, can a hitch ball become worn enough to reduce its diameter and allow for a strong upward force to pop it off?

CharlieRN

Sorry to learn of your experience @Kevin@7 - I understand what you went through as I was the one who reported a similar incident earlier this year. It's great that we were both fortunate in the sense that there was little physical damage, though in my case at least, the same is not true for the psychological impact.

The cause is still somewhat of mystery to me, with the only factor that can be completely ruled out being wear and tear of either the ball or the hitch (neither has seen much use and both have been well maintained). While at first, I too thought that the impact of the bottom of the tongue jack with the crest of a small hill was the cause, that seems likely not to be the case either. There is no doubt that the jack impacted the pavement: I heard and felt it, and was even able to see the point of impact in the asphalt afterward. Yet in post-accident testing, I was unable to get the coupling to detach even when i jacked up the trailer enough to significantly raise the height of the TV. That seems to indicate that even though the impact was real, the actual proximate cause was user error in hitching.

I'm pretty scrupulous in my hitching routine, and (even in this case) stop to double-check everything after towing a short distance. That said, there's really nothing else that can plausibly explain what happened. This in turn has dramatically raised my anxiety level over potentially repeating and overlooking a similar hitching error, and I am no longer able to comfortably tow my T@B.

DaveAnna

Maybe swap for bulldog hitch. Pretty bullet proof

Kevin@7

@CharlieRN, As I felt a big bounce and hard hit I'm thinking the sudden impact exerted forces much greater than you get by just jacking it up so that experiment will not likely reproduce the amount of force.  It's basically like taking a 400+ lb jack hammer to the connection.  I'm sure the pin and the rest of the steel might under very high and quick impact, flex to where added with some wear and tear reproduce the issue.  I too have tried to jack it up and it seems to be a very robust connection.

Mickerly

The coupler should latch or unlatch without any excessive force. If it takes too much force to latch, the ball is not above the coupler fork. When you get the handle closed by force, you are actually not coupled. When you can't get the handle open or the ball won't release, the ball is too far back in the socket to clear the fork. Push the trailer back some. The ball must enter and leave from the front of the socket to operate properly.

I stick my fingers in there too. I do make sure nothing has a possibility of moving before I check the fork under the ball. And I agree completely. All those safety protocols are present for a reason.

CharlieRN

My routine is to position the TV and hitch so that coupler on the trailer has to slide forward just a bit, down and over the ball. It's rare that I'm unable to latch quite easily on the first try using this method. It also has the advantage of providing a visual and audible confirmation that the coupler is positioned properly.

It's possible however that I missed it this time and the coupler itself was just resting on top of the ball. This would have allowed the handle to appear to latch properly (and the safety pin to be inserted.) It also would have meant that even though the coupler was resting on top of the ball, it was snug enough to give the appearance of being fully seated, and enough to actually allow the camper to be towed. My routine is to pull over after towing a short distance for one last check, which as previously noted, I did this time as well. It would seem that I also managed to overlook the misaligned coupler during this second check, something that may be unlikely but is still possible, particularly for those us of us who've reached a certain age.

edit: correct typos

Marceline

Kevin@7 said:

@CharlieRN, As I felt a big bounce and hard hit I'm thinking the sudden impact exerted forces much greater than you get by just jacking it up so that experiment will not likely reproduce the amount of force.  It's basically like taking a 400+ lb jack hammer to the connection.  I'm sure the pin and the rest of the steel might under very high and quick impact, flex to where added with some wear and tear reproduce the issue.  I too have tried to jack it up and it seems to be a very robust connection.

I think that if the coupler was properly engaged, and some kind of massive force yanked the coupler off the ball without opening the coupler, there would be signs of stress (scrape marks, deformation) on the ball and on the inside of the coupler. I don’t see how a properly engaged coupler can be yanked off the ball without causing damage. Have you closely examined the ball and the inside of the coupler? The only other possibility would be the wrong size ball (1 7/8” rather than 2”). 

Kevin@7

Not really knowing how much engagement there really is, I can't be completely sure how much deformation is needed to disengage.  Maybe I'll take a better look at my evidence inside.  Steel does have a range of deflection before permanent deformation.

I may never know what really happened but the main lesson here is always use all the backups just incase.

Binghi

I always thought that if the safety pin engaged freely that meant the coupler fork was properly positioned on the underside of the ball. Whenever the pin does not engage easily, I pull the TV forward and that seems to do the trick. Based on this thread, I think I’ll do a visual confirmation of fork placement with each hookup.

bergger

@Binghi that's what we do.  If my wife makes the connection I'll visually verify it and vice versa.  Also for people who have had it pop off.  Just make sure you actually have a 2" ball and not a 1 7/8" ball.  They are very close in size.  Also you may need to adjust your coupler.  Usually this is not necessary but it might be possible that it's just be too loose.  Most can be adjusted by tightening or loosening the nut under the latch.

StepheninDen

Wife hooked up our cargo trailer a couple of years ago because my back was out. She closed the coupler and inserted the pin but didn’t realize it was sitting on top of the ball and not attached. I was watching her and didn’t notice the difference. Trailer didn’t bounce off until we were on the highway going 60. Luckily the trailer was empty and managed to skid safely behind us on the chains until I was able to pull over. So, as others have said, you can definitely close the coupler above the ball and insert the pin if you’re not careful.

atlasb

I also used to jack the tongue up until it lifted the truck and bumper to make sure it was engaged.  I started to think about the excessive strain on the latch and stopped that practice.  I now use a small mirror to place under the latch to make sure it is indeed properly latched.  I also sometimes manually feel to make sure it is properly latched.

Also, looking at the top of the ball at the specified weight capacity of your Hitch Ball. There are several capacities of the balls and just because it is a 2 inch ball, it can have different capacities.  I use a 7000 lb ball for our 400.  

AnOldUR

atlasb said:

I started to think about the excessive strain on the latch and stopped that practice.

We all have to do what we're comfortable with, but this is actually why I continue to use this practice. If the static strain put on the coupler by simply lifting up on the ball could cause a problem, bouncing down the road would be disastrous.

Horigan

We end up effectively testing the hitch connection every time we connect the weight distribution bars.  Need to jack up the connection a fair bit to get the bars to swing into place on the trailer frame.  Agree with @AnOldUR that the system should handle this and it would highlight any worn/yielded components.

tomtek

I have some info to share not sure if it is directly related but it seems it could be.

The tab that the latch connects to appears to have a stress crack or was bent somehow.  

The tab that extends above the horseshoe was bent ever so slightly forward(1/16-3/32 as a guess) somehow and prevented the mechanism from positive locking.  The pin could be inserted but the whole thing was loose and not as locking tight as it once was.   It took so little of a bend to change the once solid latching.   Seems like the steel is probably a very mild steel that stress cracked easily.

I don't recall any specific physical situation that would have damaged it. 

The love taps you see on each side was what it took to get the hitch latch bent back into correct position to be able to use and get on the road but I am fairly certain its strength is compromised and needs replaced before next outing.  

Basil48192

I just had a similar experience with my 2021 320S!  I was heading home from the Manistee River in Michigan...about a 250 mile trip.  I hooked up, made sure the latch pin was in place and headed for home.  Everything seemed fine until I stopped at a cider mill about halfway home. 
The road out of the place was very uneven and put my rig through some contortions...but I don't think it ever bottomed out.  After that, I started noticing a slight 'clunking' noise when I would apply the brakes.  I assumed the gain setting on by brake controller needed tweaking...but nothing made a difference.  I found a convenient place to stop and I checked my hitch.  At first glance, everything seemed ok.  But, after lifting and bouncing the tongue, it actually came uncoupled with the locking pin still in place.
I reseated everything and replaced the pin and it was fine the rest of the way home.  However, I'm still confused about what happened. 
When I got home, I removed the ball from my TV and clamped it into the hitch.  It seems to be secure front-to-back and side-to-side.  However, it would move up and down...about 1/8"...which doesn't seem right.  My coupler has no adjustment mechanism that I can see and, to replace it, it seems you would have to grind off a large rivet pin.
Just thought I'd add to the discussion!

jamesdn1948

I noticed the same thing on my 2023 320S. Vertical play on the ball and no adjustment on the coupler mechanism. Not a good design. 

Maple_Geek

Silly question but have you confirmed that you have a 2" ball? 1-7/8" balls do exist and would be a bit too small for the T@B coupler.
On my 2022 T@B 320S  there is a large sticker stating that a 2" ball is required.
I do not see any up/down play on my setup.

Basil48192

@Maple_Geek.  Mine is definitely a 2" ball.  I even measured it with calipers to determine if it was mismarked.  I have contacted Nucamp for advice.  I will check my manuals to see if it calls out the manufacturer and model number of the hitch.