Torque Wrench for WD Hitch nylock nuts

[dolfinwriter]

Is this the right thread for this, first of all?

I'm trying to install a weight distribution hitch to haul my trailer of stuff from east county San Diego California to Kansas. It's a 7' x 14' cargo trailer and about 6500 lbs GTW, and I didn't need much convincing of the need for a WD and sway reduction/prevention hitch.

Here's my problem: I need a torque wrench capable of 380 ft-lbs to torque two nylock nuts. NO ONE has a torque wrench that will go above 250 ft-lbs. I've tried Autozone, Pep Boys, O'reilly, Trailer supply stores, RV dealers, tire shops, Harbor Freight, pawn shops, Lowe's, Home Depot...

How does ANYONE do this? Or is everyone who uses a hitch like this blowing off the torque spec? The BALL is supposed to be torqued to 360 ft-lbs., and LOTS of places sell hitches and balls, but NO ONE has a torque wrench capable of properly torquing it, neither to rent nor to buy or loan.

How does ANYONE do this properly if you can't get this one tool needed to do it right?

What am I missing?

I would greatly appreciate any help in this area.

[CharlesinGA]

Way late here, but the instructions the OP posted said a torque wrench capable of 380 lb/ft. They didn't say the bolts were supposed to be torqued to that, just that the tool needed to go that far. Typical torque on the two 3/4 thru bolts on most hitches is 260 lb/ft, some may go a little higher, but 380 is pretty high for the bolt, I think someone pointed out that was the max on a grade 8 bolt, most hitches come with grade 5. Thats all Blue Ox specifies, but grade 8 won't hurt anything. I have looked at the instructions for Equalizer, Blue Ox and a couple of others, they all specified 260 or close to that number.

The guy at a semi shop won't mind doing something like that. I am sure they prefer you to do it right than to have it fall apart on the road. I have a torque wrench big enough to do the ball nut, generally 450 lb/ft.

Charles

[JRscooby]

BenK wrote:
Me too...didn't know they made them that big and wonder if they provide enough "locking" force

Think a split-ring should be added

Super_Dave wrote:
360 ft-lbs and nylock nuts made me laugh.

I'm not real found of split washers on big stuff that is real critical to stay tight. Have found to many cracked. If the pieces fall out...
I prefer a piece that has tabs that bend to the flat, or wire thru fastener.
On things like hitch or lugnuts, where I will be checking to be sure not backing off, I often use paint mark where fastener meets part so I can tell at a glance if moved in relation to each other.

[dolfinwriter]

The trailer and its contents are in Kansas now, and I am back in SoCal finishing packing, purging and working on my house. I'm thankful for the sway preventing hitch after driving though some beastly crosswinds in the mountains of I-8 east of San Diego, and in Arizona and New Mexico east of Flagstaff. Mine tracked straight and smooth the entire way.

Saw an 18-wheeler on its side yesterday I believe near Winslow. I wondered if it was the same one I saw earlier in the day with the rear of its trailer crabbing sideways as much as 2 feet in the crosswinds. I saw a lot of RV trailers swaying a lot as well. Some of those were 5th wheel.

On the way to Kansas, I stopped for gas at a Love's, and I happened to park next to someone pulling a camper trailer using the same hitch I have. I asked him how he torqued it and he said he guessed. He had two small boys in the back seat of his tow vehicle, and he's guessing at things like this. He also had the trunnion bars upside-down, so he doesn't follow instructions well.

[dolfinwriter]

BenK wrote:
Me too...didn't know they made them that big and wonder if they provide enough "locking" force

Think a split-ring should be added

Super_Dave wrote:
360 ft-lbs and nylock nuts made me laugh.

There is also a flat washer and a split ring lock washer.

FWIW, the nuts that hold together some sea water components in nuclear submarines that have to withstand submergence pressure use nylock nuts on bolts that are at least two inches in diameter. These and all fasteners and software for systems that are exposed to submergence pressure are also QA'ed to the nth degree because of the Subsafe program implemented after we lost submarine Thresher. The only numbers I can state are what's been declassified at >800 ft depth, and 44#/100 ft of depth. That's 352 psi. Doesn't sound like a huge amount, but think of containing that kind of pressure in components the size of a pickup. Force = Pressure X Area.

So yeah, they do make them much larger than this.

I said before that I don't torque spec every single thing I work on, but on this hitch, it seems kind of important to have it tight enough but not overtight. One of the reviewers for this hitch said that he used what we called a "calibrated elbow" approach, and it came loose on him down the road and started swaying when trucks passed. He was smart enough to check it and had tools to tighten it, but would it have come loose at all if he had done it right?

[BenK]

Me too...didn't know they made them that big and wonder if they provide enough "locking" force

Think a split-ring should be added

Super_Dave wrote:
360 ft-lbs and nylock nuts made me laugh.

[Super_Dave]

360 ft-lbs and nylock nuts made me laugh.

[mkirsch]

dolfinwriter wrote:

mkirsch wrote:

dolfinwriter wrote:
What amazes me is the most common response I have gotten is to take it to a semi or big rig maintenance facility and bother them to borrow a proper torque wrench for this. Is that really what most people who are doctors, lawyers, cybersecurity professionals, carpenters, electricians, teachers, bankers, police officers... do? I doubt most people even know where to find one.

Most people pay the RV dealer to install the hitch.

Not sure how they can do it if they don't have a torque wrench either.

They do it, all the time. Probably with an impact gun. They probably don't even count the ugga-duggas. They've done enough of them to know what tight feels like without a torque wrench.

Folks have to keep in mind we're not building a Formula 1 race engine here. We're assembling a weight distributing hitch with big beefy castings and large bolts. Close enough is close enough, and there are ways to get close enough without having a torque wrench.

If you want to fret about having all the bolts tightened to laboratory accuracy that's your prerogative, but again, close enough is close enough.

[dolfinwriter]

I decided to just grind off the one weld bead in the middle and pry the tube away from the frame so I can slip the bracket between the frame and the tube. That leaves just one weld bead at each end of the three feet long tubes. I may slip a hose clamp or something over it to make sure it doesn't pop off, and I may eventually just cut the wires and remove these tubes, and then solder splice the wires and use plastic corrugate or something like that.

[JIMNLIN]

At that particular time we were still McDonnell/Douglas however musta' been ok...USAF inspectors bought it off. I do know this site was considered a field operation...not a manufacturing operation.

[dolfinwriter]

JIMNLIN wrote:
I used my 24" adjustable wrench and a four foot 1 1/2" sch 40 pipe...then jumped on it with my 220 lbs.
Working at the C-17 Tulsa mod center in '97. One big mil spec bolt into the wing spar had a 3400 ft lb torque. It took three 6' plus husky guys with a six foot 2" pipe on a torque multiplier to get'r done. The bolt could only be reached on top of the wing out on the very leading edge. Luckily I wasn't 6' tall.

I won't give numbers, but the torque required for head bolts on a submarine nuclear reactor cannot be reached without thermal changes, and normally only done in a shipyard.

Boeing didn't provide appropriate tools to do this wing job?

[JIMNLIN]

I used my 24" adjustable wrench and a four foot 1 1/2" sch 40 pipe...then jumped on it with my 220 lbs.
Working at the C-17 Tulsa mod center in '97. One big mil spec bolt into the wing spar had a 3400 ft lb torque. It took three 6' plus husky guys with a six foot 2" pipe on a torque multiplier to get'r done. The bolt could only be reached on top of the wing out on the very leading edge. Luckily I wasn't 6' tall.

[dolfinwriter]

mkirsch wrote:

dolfinwriter wrote:
What amazes me is the most common response I have gotten is to take it to a semi or big rig maintenance facility and bother them to borrow a proper torque wrench for this. Is that really what most people who are doctors, lawyers, cybersecurity professionals, carpenters, electricians, teachers, bankers, police officers... do? I doubt most people even know where to find one.

Most people pay the RV dealer to install the hitch.

Not sure how they can do it if they don't have a torque wrench either.

[mkirsch]

dolfinwriter wrote:
I'm also really curious how the wiring is routed on other trailers from the body of the trailer to the coupler and umbilical connector.

On any of mine, the wiring is just held to the frame by clamps.

[mkirsch]

dolfinwriter wrote:
What amazes me is the most common response I have gotten is to take it to a semi or big rig maintenance facility and bother them to borrow a proper torque wrench for this. Is that really what most people who are doctors, lawyers, cybersecurity professionals, carpenters, electricians, teachers, bankers, police officers... do? I doubt most people even know where to find one.

Most people pay the RV dealer to install the hitch.