RV Tire Safety: Lug nut torque – Part 2: Are your lug nuts tight enough?

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with RV tire expert Roger Marble

This is Part 2 of how to ensure your lug nuts are tight enough, but not too tight. The first part covered the science and engineering behind the basics, as I am expecting that there will be a number of people who will say something along the lines of, “Roger, you are all wet. I’ve done it THIS way for years and never had a problem.”

You are certainly welcome to ignore my advice and continue with the methods you have used for years. My target audience is those who are still new to the RV life and do not have years of automotive or mechanical background or training, and those that want to ensure they do not end up with a wheel coming off their RV or breaking a wheel stud. OK, let’s jump in.

I am confident that no one wants a wheel of their car, RV, trailer or dolly to come off while traveling down the road as seen in THIS video. Or maybe even worse, to cause someone personal injury as seen HERE (Caution: graphic). (The man suffered a fractured skull and chest injuries.)

So what do we all need to do to prevent a wheel coming off one of our vehicles? It’s easy. Just make sure all of your lugs nuts are properly tightened and that the wheel or nuts or studs have not been previously damaged. Sounds simple enough but how do we do that?

First, you need to know how tight the nuts are supposed to be. This information should be in your Owner’s Manual.

You can check out this YouTube video, “How To Torque / Retorque Lug Nuts – For the DIY Beginner.” Note: I covered the sequence for setting or checking the torque depending on how many lugs you have on your vehicle in THIS blog post. One important point to consider: If you had service on your brakes or tires and someone else tightened the lug nuts, how do you know they did the job correctly? Many of us have heard about or experienced an over-tight lug nut, so I recommend you set the torque yourself, as seen in the video.

Then, when you are doing the recommended “torque check” at 50, 100 and 150 miles, you will know that you don’t have a nut that is significantly over-tight. Note: If your owner’s manual has different mileage for torque check, follow that. If you find a nut that turns after the 2nd check, keep an eye on it in the 3rd check, and if still turning, you need service as something is wrong.

Let’s review the tools you will need and which were seen in the video.

Remember this info is aimed at owners of RVs with tires smaller than 19.5″. So if you are in a Class-A you can read to understand what is happening to your “baby” when you call the service truck.

Tools: Torque wrench, 6-point socket of the correct size for your nuts, 2′ “breaker bar”, 12″ long 1/2″ drive extension to allow you to get to your dual wheel nuts. Note: Trailer owners may not need this tool.

You will probably not need to use these tools too often, so top-quality (expensive) is not needed. In those cases I head for Harbor Freight for low-cost tools.

Check these links:

1/2″ drive torque wrench. Harbor Freight or Lowe’s or Amazon.com

1/2″ drive extension. Harbor Freight or Lowe’s or Amazon.com

6-point “impact”-rated socket – I recommend you not use a “12 point” socket as they are more likely to spin off or round off your nuts. You do not need to buy a set. You might want to confirm the size by borrowing a socket from a friend or fellow RV owner. Example: 13/16″ Lowe’s or Amazon.com

Note: It might be better to go to Lowe’s or similar as you do not need a set, but be sure to get the correct size, not something “close enough” or you can damage the lug nuts. Here is a 3/4″ socket from Lowe’s or Amazon.com.

Now, how do you get the tight nut off? A 2′ long breaker bar will make the job easier. This is what I use (from Harbor Freight), and I can easily generate 200 Ft-Lb. Here is a selection at Amazon.com.

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OK, so with all the tools you may need now collected, how do you set your clicker torque wrench to the spec for your vehicle?

Here is a YouTube video to help those who have never used a torque wrench. And you can check out this “entertaining” YouTube video from a guy in Australia on “How to Tighten Your Wheel Nuts – The Right Way.”

We hope this helps, and if these couple of posts help a few RV owners avoid problems we will be happy.

 

Read more from Roger Marble on his blog at RVtiresafety.net or on RVtravel.com.

 ##RVT950

 

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Ed Lacrouts
3 months ago

Roger. How to use a “torque” multiplier to get a required 200 lbft on my trailer tires?

Roger Marble
3 months ago
Reply to  Ed Lacrouts

Sorry but don’t the instructions tell you this? I think there are more than one brand. BUT I think they are primarily intended for removing tight nuts and not for accurate setting of initial torque. If your spec is 200 Ft-Lb then you need to get a standard torque wrench that can go to 250 Ft-lbs.

Snayte
3 months ago

Interesting. I had no idea when re-torquing after 50 miles etc. That you are supposed to back off the nut and re-tighten. I was also unaware that this should be done when the wheel was cool. My tire installer did this wrong when I brought my truck back in for the 50 mile torque check.

Roger Marble
3 months ago
Reply to  Snayte

I would not back-off and re-tighten. I will review my post to confirm it doesn’t say to do that. If you set the torque correctly initially you only need to confirm the click of the torque wrench. Only reason to back-off and tighten is if you don’t trust or know the torque was set correctly the first time.

Wayne
3 months ago

I have seen conflicting information regarding lubricating the threads. The majority say clean unlubricated threads as lube can result in over torqued lug nuts. I’m not an expert, just pointing out the contradiction.

Roger Marble
3 months ago
Reply to  Wayne

Yes “Clean and dry” or unlubricated is the stated “correct” way to go. I agree that oil and wheel bearing grease is not the way to go even though some say that is OK. Once you study the science of torque and bolt stretch/strength you learn that the closer you can be to “Clean and dry” the better as that will be closer to the desired bolt/stud stretch. I will admit to using WD-40 myself but I also tend to tighten to 90% of torque spec. Follow your owner’s Manual instructions

Wayne
3 months ago
Reply to  Roger Marble

Thanks Roger. It was the very confident Aussie video stating axle grease on the threads is “essential” that made me wonder.

Roger Marble
3 months ago
Reply to  Wayne

Yes Clean and dry is the best. The guy from Australia and some others claim grease is OK but you will not be setting the torque correctly. I am setting up a test to get measurements so i can post some data. Keep watching over next few weeks.

Thomas
3 months ago

took my truck into the dealer for free rotation. When I got home I wanted to check if they torqued them right. I could not budge them. My tourqe wrench goes to 250 pounds feet. I could not break them loose.Back to the dealer, I was pi$$ed. Chev says 140 ft #,s they did not even apologize. What would have happened out on the road when I couldn’t remove the tire. I can change my own tire

Roger Marble
3 months ago
Reply to  Thomas

That is why I suggest you set the torque yourself. Your Service manager needs to explain how he knows he has not over stretched any of the studs. Ask to see his information in writing (he will not have any). Ask if he will guarantee no broken studs in the future? (he will not) Then ask why you should have the dealership do service in the future. I had this happen to me once and I demanded the store owner remove the nuts with the stock lug nut wrench. He could not so he got the message.

Stan Wutka
3 months ago

Also, make sure the socket you have will fit the wheel. 2 years ago bought a new trailer with fancy aluminum wheels. (Old trailer had steel wheels). Went to check the torque of the lug nuts and the socket I carried in my truck would not fit the in the opening of the wheel for the lug nut. It was an impact socket, thick wall. Had to a get thin wall socket to fit and carry with me. Glad I checked it before I had a flat tire .

Roger Marble
3 months ago
Reply to  Stan Wutka

Yes you should always confirm the socket, extension, braker bar and Torque wrench ALL fit properly.