Ball Loosened, Use Loctite?

[32vld]

From time to time my son or I have to tow bar
his 1946 Chevrolet 2 ton rack truck. He uses it
for his food catering business.

Being it is old it breaks down once a year. So
when booked to do a party he has to get his truck
there so it is towed with a Chevy Suburban.

Well the truck just had to have the head R&R so the
truck had to be towed a few times. This time I bought
a new draw bar and 2" ball to get the tow bar level
when towing his old truck.

The problem is that the ball came loose after a few
tows. Last year we had to tow his truck for many weeks
because his engine was at the machine shop getting
rebuilt and we never had any problems using another
draw bar and ball.

I did not have a 1.5 wrench so I went to my neighbors
house, retired mechanic. He tightened down the nut
with a long combination wrench. Then doubled up the
wrench and gave it another tug.

Any ideas why it loosened?

He used anti seize grease when tightening the ball
to the draw bar. He said incase you ever have to take
it apart. I never did that before.

Could that of caused the ball to loosen?

Is it a good idea to clean off all the threads and
apply Loctite?

Thanks for your help.

Here is a link to my son's website so you can see his
truck:

http://www.pizzarita.org/

[Community Alumni]

BenK wrote:

Here are the potential laws of physics on using an extension arm without a means of measuring the amount of force that generates torque...

For discussion purposes...assume the wrench is about 12 inches long, or one foot long

Add in that five foot long handle extension and you will have a SIX foot lever arm on the wrench head, as proxim says..."It's not hard to reach the high torque requirement"

But...what is the ball's torque specification vs what is it actually torqued to???

Add that some folks turn the shank 90*. To then stand on the wrench that may have an extension on the handle

Two scenarios here

#1...pull with your arms and body on that wrench handle/extension. Think I can pull will all my might to about 150lbs for discussion purposes.

150 lbs x 6 ft = 900 ft/lbs...well over the typical 2 5/16" dia ball's typical 450 ft/lbs. Might even over tighten enough to stretch the ball's shank past plastic and into yield. That would explain it coming loose...again and again...it no longer has the tensile strength to hold that amount of torque

#2...standing on the wrench when the shank has been turned 90*.

I weigh in at about 180 lbs...

180 lbs x 6 ft = 1,080 ft/lbs if I just stand on it...if I 'jumped' on it...there will be a multiplier and for discussion purposes...say 2 times. That would mean it now has about 2,160 ft/lbs of torque on that nut/shank.

Really not that silly. I've seen it done both on automotive and in industry and had had to repair them

If needed...borrow/rent/etc a torque wrench rated for the torque your 2" ball needs

Am of the opinion that your neighbor over tightened that nut/shank and ruined it forever. It will NOT ever hold...even with a brand new "split' lock washer...sized for that nut/shank

Here are some links to sites that list tow ball sizes and their 'typical' torque requirements


Reese Ball specifiations


Draw-Tite ball specifications


eTrailer ball specifications


eTrailer Expert site for questions and answers


{edit}...forgot to touch on what the OP is towing with this 2" dia ball...take a look as his link to his son's business and the truck/kitchen/refrig/etc it holds/carries/etc...it is NOT a small pickup...but a custom flat-bed truck. On this...think a 2" dia ball is undersized...but many will use the derogatory 'Weight Police'...of which I proudly wear...as my comments are normally on the conservative side...as I have to sleep on what I've posted/said...

http://www.pizzarita.org/_nuxt/img/truck.8664c3c.png

PPS...a VERY COOL setup and if out here in my neck of the woods...would love to hire for a party/event

http://www.pizzarita.org/

I guess I apply a bit more common sense when tightening down the nut. I use the pipe so that I don't have to pull with all of my might. I'm tightening down the thing, not trying to beat it into submission.

[BenK]

Oh...my bad if that is what Time2Roll meant and my apologies for lumping that comment in with the ones out in left field that gives me a headache...

On the crows feet thing...

ANYTHING

that changes the moment (lever arm) changes the multiplier/lever arm ratio of the 'same' force applied.

The moment is measured from the center of the fastener's axis of rotation to the point on that force is applied. The why of some torque wrenches having the handle on a pin/pivot...and/or instructions to hold it only on the 'handle' area

I've never seen any crows feet that keeps the fasteners axis of rotation in the same line as the torque wrench head's axis of rotation

Do find the humor in the discussion on torque sticks vs laws of physics...magic is how many thought of them when they first used one...

time2roll wrote:

BenK wrote:

time2roll wrote:
WHEN INSTALLING REESE HITCH BALLS:
torque all ¾" shank balls to 160 ft. lbs., all 1" to 250 ft. lbs., and 1¼" shank balls to 450 ft. lbs.

(all are virtually the same)

Guess some folks think 16 oz of beer is.....'virtually the same'......as a liter of beer... :R

I looked at all four of your links and the specs were virtually the same.
IIRC etrailer was 150# on the small one.

[mike-s]

babock wrote:

mike-s wrote:
Depends on how far the crowsfoot extends, as I've already said. A 6" extension at 90 degrees on an 18" wrench would result in an error of over 5%. 3% is a common calibration accuracy for torque wrenches, so it can make a meaningful difference.

The length of the torque wrench itself means nothing. Never seen a crows foot longer than an inch.

6" torque adapter

[Bob_Olallawa]

32vld wrote:


Well the truck just had to have the head R&R so the
truck had to be towed a few times. This time I bought
a new draw bar and 2" ball to get the tow bar level
when towing his old truck.

The problem is that the ball came loose after a few
tows. Last year we had to tow his truck for many weeks
because his engine was at the machine shop getting
rebuilt and we never had any problems using another
draw bar and ball.

I did not have a 1.5 wrench so I went to my neighbors
house, retired mechanic. He tightened down the nut
with a long combination wrench. Then doubled up the
wrench and gave it another tug.

Any ideas why it loosened?

He used anti seize grease when tightening the ball
to the draw bar. He said incase you ever have to take
it apart. I never did that before.

Well after a bunch of posts about how not to tighten the ball on the hitch, take the setup to a shop that has the proper tool for the job and pay them to tighten it up right for you.

[babock]

mike-s wrote:
Depends on how far the crowsfoot extends, as I've already said. A 6" extension at 90 degrees on an 18" wrench would result in an error of over 5%. 3% is a common calibration accuracy for torque wrenches, so it can make a meaningful difference.

The length of the torque wrench itself means nothing. Never seen a crows foot longer than an inch.

[mike-s]

babock wrote:


There is more error in the setting of the torque wrench that what there would be using a crow's foot at 90°

Depends on how far the crowsfoot extends, as I've already said. A 6" extension at 90 degrees on an 18" wrench would result in an error of over 5%. 3% is a common calibration accuracy for torque wrenches, so it can make a meaningful difference.

[babock]

There is more error in the setting of the torque wrench that what there would be using a crow's foot at 90°

[mike-s]

babock wrote:
Actually it doesn't if you set the crow's foot to 90°.

Use this calculator to prove it.

http://www.cncexpo.com/TorqueAdapter.aspx

Thing is, the math on that site is wrong, so it "proves" nothing. And, they don't show their work - I can only guess that they're naively and incorrectly using Cos(A) as a factor.

For small offset crowsfoots (feet?), it doesn't make much difference at 90 degrees, so can usually be ignored. But, if you use a longer extension, it does. The change in applied torque is related to the ratio in distance of the original effective lever length, and the actual length with extension in place. Basically, the length of the hypotenuse of the right triangle formed by the wrench and the extension.

[babock]

mike-s wrote:

babock wrote:
A crows foot extension when set at 90° to the torque wrench does not change the torque setting.

Actually, it does.

Actually it doesn't if you set the crow's foot to 90°.

Use this calculator to prove it.

http://www.cncexpo.com/TorqueAdapter.aspx

[RCMAN46]

Can not believe 4 pages about a hitch ball. If properly torqued and ball greased there should not be a problem.

Use locktite if you want but if you ever want to remove the ball heating of the nut will most likely be needed. Only use blue locktite.

[32vld]

Draw bar used last year was rated 6,000 lb.
Ball rated 7,500 lb with a 1" dia threaded shaft.
Never came loose.

New draw bar rated 7,500 lb.
Ball rated 12,000 lb, 1" threaded shaft.

Difference is that never seize grease was used,
which I never did in the past.

That I was not the one pulling on the wrench, my
neighbor did. Though it appeared that he pulled
hard.

Truck weighs less then draw bar weight rating.

[mike-s]

babock wrote:
A crows foot extension when set at 90° to the torque wrench does not change the torque setting.

Actually, it does.

[babock]

A crows foot extension when set at 90° to the torque wrench does not change the torque setting.

[time2roll]

BenK wrote:

time2roll wrote:
WHEN INSTALLING REESE HITCH BALLS:
torque all ¾" shank balls to 160 ft. lbs., all 1" to 250 ft. lbs., and 1¼" shank balls to 450 ft. lbs.

(all are virtually the same)

Guess some folks think 16 oz of beer is.....'virtually the same'......as a liter of beer... :R

I looked at all four of your links and the specs were virtually the same.
IIRC etrailer was 150# on the small one.

[mike-s]

wnjj wrote:
A torque stick may well limit the output torque and a truck suspension would work similarly, but ONLY if you get the rear wheels off the ground. Then and only then will you no longer be able to apply a higher torque...All the suspension of the truck does is cause you to have to travel the wrench handle further to build the needed torque.

Yep. Unless you're deforming (twisting) the torque stick so much that the wrench won't click. If the wrench clicks, the torque is right. The "springiness" of torque sticks can make it harder to get the torque precisely - same as with a beam type torque wrench - but the solution is just a matter of applying force smoothly.

Extensions are another matter. In relation to torque wrenches, common socket extensions (i.e. axial ones, like torque sticks) don't change anything. A "crow's foot" type extension does make a difference.