Torque your Nuts!

[MTPockets]

Picked up our new Big Horn 3055RL on October 31st .... I re-torked the wheel nuts to spec right away and found all of them were loose. In late November, I re-checked wheels and all we OK. I also checked the pin box mounting nuts and found two were below spec.

Today, I had some time and decided to re-check the wheels - All O.K.
King Pin Bolts - "FIVE" loose bolts, well below spec.
Axle U-Bolts - "ALL" 16 nuts were well below spec
Axle hanger bolts - All O.K.
"ALSO" Got in garage behind panel to look at the maze of water lines and electric cables, etc..... Found a small water leak which was an easy fix by tightening a nut - also found five other water line nuts that were very loose .....

I was a bit surprised to find so many loose nuts, but the maintenance guidelines tell you to check these things often - Fortunately, we've only travelled about 500 miles since new - Made me a believer..

FYI

 

[dfk009]

Thanks for the advice on your lesson. Better check our 2012 ElkRidge. I'm wondering how many dealers check these items during their pre-delivery service? If it's like car dealers, they worry more about the looks, than checking the vehicle from front to rear. After 31 years at a dealership, I've seen it all. Again, thanks for the warning!

Don

 

[jmgratz]

Bouncing down the road will have a tendency to loosen everything. We check our often also and have found things loose more than once.

 

[Westwind]

Thanks for the reminder - Had to get a new socket for my Torque Wrench so that I could tighten up the lug nuts on our new Bighorn, our TT had regular lug nuts but the new one had to have a 7/8 deep socket.

 

[jmgratz]

I check my nuts regularly and keep them torqued.

 

[PeternLiane]

Where does one find all of the torque ratings for all of the bolts?

 

[jnbhobe]

Peter; you can use this chart http://raskcycle.com/techtip/webdoc14.html There are many more,your probably looking at 90 to 120 ft lbs.

 

[Birchwood]

Don't rely on power(pneumatic) wrenches to torque them properly.Torque them
with a hand torque wrench.The Heartland manual that comes with the RV has the values
for torque.

 

[Westwind]

I have always torqued mine the day before we left and stopped at a coffee stop about an hour into our trip and torqued them again which was more a effort in exercise for me which doesn't hurt.

 

[CactusTwo]

Like they say " A torque wrench in hand is better than you too off the road and into the bush"...or something like that! Everyone travel safe
Len

 

[KENNY COCHRAN]

With alum. Rims you need to torque a new rv, (or when you change a flat!!) every 50 miles for the 1st 250 miles. Then every now and then. Don't forget to torque them after you change a flat. (experience, mine came off and rolled right past us).

 

[57chevyconvt]

Threads (nuts or studs - fine or coarse) when tightened are in effect sliding on each of the metal surfaces. When threads are not lubricated can have a high coefficient of friction. This is especially true on new threads. All machine cut threads are subject to the quality of the machines cutting tool. This is one reason that re-torquing of lug nuts is recommended. As the pressure of one metal surface is place on the other surface, the metal will yield and the threads (nut and stud) will loosen. I have a practice on all of my lug/nut applications of removing the nut, clean the very fine metal particles and lubricate the stud with an assembly paste. The assembly paste contains molycote and is made by Dow Corning. When the threads are cleaned and lubricate the coefficient of friction is greatly reduced and the clamping force of the threaded fastener is increased as much as 30% when properly torqued. Think of the stud or bolt as a spring, as the spring is stretched, the clamping force are increased, as the clamping force is decreased by lack of proper torque or gaulded/non-lubricated threads the threaded joint becomes loose and Kenny's experience factor becomes a reality. So my recommendation is to clean, lubricate, and torque the lugs/nut.

 

[KENNY COCHRAN]

You talking about loctite or similar product for the threads or what?

 

[57chevyconvt]

The "assembly paste" that I made reference to is not a Loctite product. It doesn't lock the threads, but lubricates. The paste is a lubricant that is formulated for assembly of fastener threads. I will post the Dow Corning product number in a few days, after I return home.

 

[MTPockets]

I not familiar with "Assembly paste" - Torque values change when threads are lubricated.

As a rule, when a bolt is installed, the nut(over a washer) should be turned and not the bolt's head. Unless a torquewrench is used the tendency is to undertighten large bolts and overtighten small ones. Suggested torques are available on-line. These suggestions do not apply if the bolt or nut has been specially lubricated unless specifically states the torques are for lubricated threads. In all cases, the specifications of the manufacturer of the equipmentshould be preferred to tables of approximations like these.
If a lubricant is used (for example,oil, grease, anti-sieze, Loc-Tite, etc.) a table for
lubricated bolts must be used since any product that provides lubrication allows for more bolt stretch at a given torque setting, and may result in over-stretching or breaking the bolt.

 

[jpajax]

BOLT TORQUE FACTORS
LUBRICANT OR PLATING TORQUE CHANGES
Oil Reduce torque 15% to 25%
Dry Film (Teflon or moly based) Reduce torque 50%
Dry Wax (Cetyl alcohol) Reduce torque 50%
Chrome plating No change
Cadmium plating Reduce torque 25%
Zinc plating Reduce torque 15%

 

[57chevyconvt]

The assembly paste that I made reference to is Dow Corning Molycote G-n assembly paste, see Dow Cornings website for technical specification and application. Yes, it is a lubricant and yes it will allow, via lubrication, to increase the bolt tension/stretch of the stud at the torque value recommended by Heartland and Lippert/Dexter. There are many factors that enter into the equation when it comes into designing a bolted joint. Strength of bolt/stud is only one, lubrication of threads, amount of applied torque are others. In my previous post, I was not trying and hopefully did not convince anyone to do something that they are uncomfortable with and that is applying lubrication to a stud and nut combination on your trailer wheel hubs. That being said, I do not allow the folks at the local tire shop to remove or install the lug nuts on my car, truck, or trailer with an air impact wrench unless the lug bolts have be properly clean and lubricated with the 'assembly paste'. I have had tire shops to gall nuts on studs that have to be removed by excessive force which destroyed the stud/nut. I just don't relish this experience when changing a flat in 'no mans land.' When thread gall does occur, very little clamping force is applied by bolt tensioning and that is the result of torquing. I do appreciate the comments and additions to thougths and intents that I tried to express in the way of added thoughts and knowledge of what takes place when we apply proper tensioning or torque to the lug bolts on our vehicles and trailers. The way I view this venue is to let the knowledge flow, please.

 

[PeternLiane]

Peter; you can use this chart http://raskcycle.com/techtip/webdoc14.html There are many more,your probably looking at 90 to 120 ft lbs.

Thank you, Looks like I'll have to get my self a nice torque wrench.

 

[57chevyconvt]

Peter,
FYI - Torque wrenches are not all the same. I bought a 1/2" drive torque wrench to keep in the truck from Harbor Freight for the sole purpose of having it available while on the road. Little did I know that the calibration and resulting torque value of a given setting was way low. The most accurate are the wrenches with the dial read-out, but they are much more expensive. I use my Snap-on dial indicator torque wrench to calibrate the ratchet type wrenches.