Confused - T@B hitch height different from what Nucamp says it should be

JamesK

I'm the new owner of a 2018 T@B 320S Boondock.

I'm confused by the difference between what I'm being told and what I'm seeing in terms of the correct hitch height for my T@B.

The previous owner measured the "B" dimension and found 16".  When I measure it, I get around 16.5" for the "B" dimension and about 18.5" to the top of ball in the T@B's coupler mechanism. The chamber for the ball is about 2" so this all makes sense to me and is roughly consistent.

When I called Nucamp (twice) they were adamant that the top of the ball on the 2018 T@B 320S Boondock is around 20".  I verified they were not talking the top of the coupler, but specifically the distance from ground to the top of the ball holder.

As an aside, I know there are a few too many threads on hitch heights.  I did spend a number of hours reading everything I could find on the forum about this.  My take away is that 16" for "B" is what many see and is consistent with the only chart I could find.

At the end of the day I will pick a height that makes the tongue of the T@B ride level on my 2021 Grand Jeep Cherokee.  But I feel like I'm missing something here and I'm hoping someone can point that out to me.  Or maybe Nucamp is wrong?


Thanks!

 

MuttonChops

@JamesK ;  Welcome to the T@B Family.
                   You have purchased a wonderful, great, little travel trailer.

IMHO the person at NüCamp is in error.  I created the Typical Hitch Height Table you referenced back in 2018 based on input from 2016 to 2018 model year owners and NüCamp literature.  Then as now there was mass confusion on what the " B " dimension is from the factory.

My 2018 320S with 'Boondock' axle & wheel/tires (when level) has  " B " at 16-inches.

BTW, if you cannot get a Tow Vehicle Drop/Rise to create a level TV & T@B general rule-of-thumb is to have T@B tongue slightly down to increase tongue weight a bit and help control sway.

JamesK

@MuttonChops, very appreciated. The measurement OCD engineer in me likes things like this to sanity check.  So that was confusing me. 

I've also noticed that once you calculate drop/rise height and then buy a ball holder with that drop, it isn't exactly as states. A 4" drop, for example, can be 1/2" different, depending on manufacturer.

So my car's receiver height is 21", my tab is 16". So 5" drop. Easy.  Closest I can find is a 5.75" drop. I slide it in and the shank where ball mounts sits is at 14.5".  I would expect 21-5.75=15.25", not 14.5"

So I'm guessing this whole area of hitch height has some black magic that takes experience to understand.

MuttonChops

@JamesK;  LOL fully understand the Engineer mindset.
                 You just need to reset your mind to 1950's when tolerance
                  of everything was in whole inches

Side Note:
    TV rear will sag some when tongue weight is added.
    Honda is one of few manufacturers that provides an estimate 'sag'
    value in their Owners Manual.
    My Colorado when empty is not level (rear about 1.5 inches high)
    so the T@B tongue weight sags the rear so the Colorado sits level
    - - - thought GM was smart to do that - - - while lots of Colorado
    owners always run empty and install leveling kits
   . . . Just use the truck as a Truck is my solution

JamesK

@MuttonChops LOL. Yep.  On my Grand Cherokee it comes with load leveling suspension so it is supposed to pretty much remove that variable from the height question.

Denny16

The Jeep load leveler system re-levels the Jeep GC based on the tongue weight being applied.  It does not adjust to make the trailer level.  You need a hitch drop in the rough ballpark of the height difference. 

cheers

JamesK

@Denny16, Yep.  Understood. It works to keep the GJC at a consistent receiver height only. 

dlb

Load leveler systems on vehicles require real world assessment.  Hitch it up, go look at it and measure.  Been doing this for years with boats and now out Tab on multiple vehicles.  Even a kayak trailer (light weight for sure) causes the suspension to load level….

All my pre delivery planning and calculating gets me into the ball park but it rarely is how I end up with the final tow set up.  As a result I have quite the collection of draw bars.

Tyreaus

@dlb Regarding this hitch height issue. I am about to take delivery of a Tab 400 BD and I also own a 2020 Audi SQ5 purchased with towing this trailer in mind. I understood that the air suspension is an optional item and did not include it on my vehicle consequently I expect some sag. I don't yet have the hitch ball but would appreciate any guidance on what I'm looking at. Also would enjoy your general commentary/advice on towing this trailer with the SQ5.

dlb

@Tyreaus I think I have a 6 inch rise for my hitch.  As for towing with the SQ5, all is good. Acceleration is very good, the trailer tracks well and braking is true.  You will need to get a dealer installed brake controller since it needs to interact with all the safety sensors.  This keeps your warranty in place as well.  Your MPG will decline by about half depending on speed and terrain.  I did install a rear view camera on my Tab and like it a lot.  

DenverJaguar

dlb said:

@Tyreaus I think I have a 6 inch rise for my hitch.  As for towing with the SQ5, all is good. Acceleration is very good, the trailer tracks well and braking is true.  You will need to get a dealer installed brake controller since it needs to interact with all the safety sensors.  This keeps your warranty in place as well.  Your MPG will decline by about half depending on speed and terrain.  I did install a rear view camera on my Tab and like it a lot.  

Why would the dealer need to install a brake controller? I'm going to have the Autowbrake controller installed directly on the tongue; there's no need for the dealer to do anything and none of the sensors on my Volvo XC90 need any involvement. 

dlb

You have a Volvo.  This is specifically for an Audi.

SLJ

I was told by the dealer when I bought my Boondock that the 2021 T@B 320 S top of ball height is 19"
2021 T@B 320 S Boondock is 21". My receiver ball top is at 19" and there's a slight tilt down.

CharlieRN

Why would the dealer need to install a brake controller? I'm going to have the Autowbrake controller installed directly on the tongue; there's no need for the dealer to do anything and none of the sensors on my Volvo XC90 need any involvement. 

I don't want to hijack this thread since it's really about tow ball height, but did want to suggest to @SLJ to double-check with a Volvo dealer or good indie shop regarding adding a hard-wired brake controller. Adjustment/updating to the car's software through VIDA is often required when it detects a new, unfamiliar system, though I admit my experience is with older Volvos. It was part of the reason that I went with the Prodigy RF on my 2008 XC-90 rather than the Redarc I'd been considering.

CharlieRN

Tyreaus said:

@dlb Regarding this hitch height issue. I am about to take delivery of a Tab 400 BD and I also own a 2020 Audi SQ5 purchased with towing this trailer in mind. I understood that the air suspension is an optional item and did not include it on my vehicle consequently I expect some sag. I don't yet have the hitch ball but would appreciate any guidance on what I'm looking at. Also would enjoy your general commentary/advice on towing this trailer with the SQ5.

There is always the option of an adjustable hitch. It eliminates the guesswork on height but does have some other drawbacks.