Check your lug nut torque!

[Tony_In_Lake_Elsinore]

Sent: 5/8/2005 11:03 AM

I had a very close call last weekend.  Drove 130 miles.  Exited the freeway -- only 8 miles to go.  Heard a thump, thump, thump -- once per revolution of the wheels.

Stopped.  Looked everything over.  Couldn't find anything wrong.  Took off again.

Thump, thump, thump.  Stopped again.  Couldn't find anything...

I would have sworn the sound was coming from the right rear.

Anyway, I proceded to my campsite.  I blocked the front wheels, jacked up the right side, put it in neutral, released the brake and turned the wheel.  It was smooth as silk.  No aparent problem.  Hmmm....  So, just in case, I jacked up the left side.

Then I noticed the problem.  A lug nut was missing.  In fact, a bolt had sheared.  Upon further inspection, I noticed that ALL the lug nuts were LOOSE!!!

I tightened the remaining nuts and made it home just fine.  This was a very dangerous situation.  I've learned an extremely valuable lesson.  CHECK YOUR LUG NUTS BEFORE YOU LEAVE!!!  Also, because it "sounds" like it's on one side, it could certainly be the other!

Can you imagine going down the freeway at 60mph and losing both wheels on one side?

[Cooneytoones]

Sent: 5/8/2005 11:41 AM

Tony...Thank goodness you found it in time and no more damage was caused....to you your passengers and your rig....Yes I know from first hand experiance what it's like to loose a set of duals..not on my Winnie, but on an International 28ft box truck..with a max load...Not fun...not to mention extremely expensive.......Have your bearings checked when you replace the stud....My mishap was caused by the inner wheel being flat, (paasenger side) and then driving about 50 miles... causing the tire to wobble enough and put enough pressure on one wheel to destroy the bearing, and bye bye both rear wheels, (on one side) and the axel......I was lucky there was no one beside me and the truck made it to the shoulder of the interstate without flipping over...When ever you leave for a trip double check your lugs, and tire pressure...The rigs with the square inner wheel lug, that lug has to be tight 1st....before tightening the outside 1 1/2 inch nut....so I will always, loosen the outer wheel, jack it up, tighten the inner lugs, then tighten the outer lugs....then (very important....check the lugs agin within 40 to 50 miles of driving.....Lugs loosening up (all by their lonesome) is also one of the reasons lubricating the lugs is not
recommended......Keep safe....Check Your Lugs...add that to your pre trip check list....Before you take a trip..within the first 50 miles....and before you leave on the return trip. There's no such thing as being too safe with your tires........
Timmy

[HeavyHaulTrucker]

Sent: 5/8/2005 8:07 PM

This is a subject that most RV'ers know very little about -- wheel lug nut torque.

If your Winnie uses Budd wheels (identified by a square-headed inner "spool" holding the inside tire, and a larger lug nut holding the outter wheel), your inner torque has to be 275 - 300 ft/ lbs; the outter torque is between 325 and 350 ft/ lbs.  IF YOU ARE USING A REGULAR LUG NUT WRENCH, YOU CANNOT TORQUE THEM PROPERLY!!!!

If your Winnie uses a single lug nut to hold both wheels, these are called "Pilot Hub" wheels.  The torque on each lug nut has to be around 300 - 350 ft/ lbs.  Again, you are not going to be able to torque them properly.  The Budd wheels use 450-500 ft/ lbs for both the Budd nut and the lug nut.

If you must remove your lug nuts, torque them as tight as you can with your lug nut wrench, then drive slowly to a truck stop or truck tire shop and have them re-torqued to specs.  Failure to do so will eventually result in the situation that happened to Tony.

John

[bboat101]

Sent: 5/9/2005 3:47 PM

I thought my manual (for a '69) says to torque the wheels to around 250 lbs.
brian

[HeavyHaulTrucker]

Sent: 5/9/2005 3:58 PM

Brian, on yours that is probably right.  In the 1970's era chassis, I believe they switched to heavier axles with stronger lugs.  The numbers I quoted are from a 1978/ 1979 manual, but would also apply if your wheel studs have been replaced with newer ones of HSLA steel.

John

[Froggy1936]

Sent: 9/4/2005 11:32 PM

As per my owners maual, after installing wheels or new tires, nuts should be retorqued @
100 mi then again @ 1000 mi then every 3000mi there after.  Then rotated @ 6000mi & start all over again.
Froggy.

[Easybago]

Sent: 11/25/2007 8:40 PM

Bumping this up to remind everyone to check those lug nuts!

When leaving the race track this morning, I heard a thump, thump, thump that seemed to be getting worse. I finally found a place on the side of the road large enough to pull over. I did a visual of the drive train but couldn't see any problems. I called my friend, who was only a couple of miles in front of me with his RV and he turned around and came back to help out. We got the wives into his RV and proceeded to do a short test drive with mine as he stood in the rear of the coach listening to see what side the thump was coming from. He determined the thumping was coming from the rear driver's side. We eased back to his RV where we inspected things closer and that's when I found a broken wheel stud and all lug nuts were loose. Thank God the large lug wrench was in the storage area! We tightened all lug nuts all the way around as tight as we could by hand and that did the trick good enough to get us home with no more thumping.

This could have been a lot worse!

Check those lug nuts!!!

[denisondc]

Sent: 11/26/2007 10:30 AM

I like to check my lug nut torque about once a year - but I do it by loosening them first, then retightening; one at a time.  I use the 'audio' method.  When a clean dry lug nut screeches loudly on a clean dry stud and a clean dry mounting surface on the wheel - then I figure its tight enough.  This normally happens when I stand on the end of the steel bar that is extended at right angles from the lug nut wrench, and most of my weight (190#) is about 3 ft out on the bar.   I dont jump on it.  That is needed when I got to loosen them a year later. 
   If your lug nuts go for several years without being moved - it might take a large impact wrench to loosen them, or even careful heating with an oxy-acetylene torch.
   
While we are on the subject of -checking-; I check the hose clamps on my cooling system, fuel system, and transmission cooler lines about once a year also.

[Lefty]

Sent: 11/26/2007 5:17 PM

I'd like to mention an often overlooked fact. Each wheel stud on a Budd 5-lug wheel is designed to carry 1/5th. or, 20% of the total load. When you lose one stud or nut, each remaining one must now carry 1/4th. or, 25% of the load. Lose two, and the remaining each carry 1/3rd. or 33% of the load. So you can see how important it is to ensure that you are using all five lugs.
Example;
Rig weight is 12,500lbs.
You have 8,000lbs on the rear axle, and 4,500lbs on the front.
Each rear stud carries 800lbs. (10 studs/8000=800)
Each front carries 450lbs. (10 studs/4,500=450)

Now, say you break a rear stud.
You had 8,000lbs, or 4,000 per side. Before they carried 800lbs each, but now the studs on that side are carrying 1,000lbs each. (4 X 1,000=4,000)
Break another, and each one is carrying a whopping 1,333lbs. (3 X 1,333=4,000)

At that rate, you can easily overload the remaining wheel studs and cause a total failure of the studs. resulting in a lost tire/wheel.

[Slantsixness]

Sent: 11/30/2007 9:29 AM

Check wheel lug torque every trip. It only takes a few minutes, and I do it when I check tire pressure.

Checking this torque is ok when the wheels are on the ground, but it even one is loose, you have to jack the weight off the wheel(s) before tightening, or you can (and will) break studs. The added weight of the motor home will not allow you to draw the wheel back in properly, and sometimes not at all. If your lug nuts are loose, or come loose, REMOVE THE AFFECTED WHEEL(S) and INSPECT THE STUDS. it only takes 1 second at highway speeds (about 50 wheel rotations) with loose lugs to damage the wheel studs, and damage them to the point of shearing or fracturing. To hear of someone driving at even low speeds with the tell-tale thumping makes me cringe. If I saw that one stud actually broke off, would concern me even more about the remaining studs and their condition.

Frightening. (but I would attempt drive it home like that, at greatly reduced speed)
 
I don't loosen the lug nuts every trip, but once a year, I remove the entire wheels and either rotate the tires, check the brakes and repack the rear bearings. I'll let the front bearings go for two or 3 years, but I check the play in them and how smooth they turn.

[HandyDan]

Now I'm totally confused.  I thought the torque for 5 stud front wheels and 10 stud rear wheels was 180 ft/lbs.  But you are saying that I need to be at least double that.  How in the world do you tighten them to 300-350 ft/lbs and wouldn't that be harmful to the studs?  I would like to see that in a manual somewhere.

[ClydesdaleKevin]

LOL Dan!  They are talking about the old Dodge chassis Budd wheels...on your Holiday Rambler with the Chevy chassis, you are safe just tightening them as tight as you can with a 4 way lug wrench.

Kev

[Oz]

I can tell you it is in the Dodge manual.  Couldn't believe it myself.  At only 170lbs myself, I used a long breaker bar and a long cheater bar to torque mine and to get them off again. 

[DaveVA78Chieftain]

 A torque wrench is calibarated at a distance of 12".
100lbs of torque = 100lbs of force (weight) applied 12" distance from the center of the bolt.

If you double the distance (ie 24") then that same 100lbs of weight at 24" applies 200lbs of force at the bolt center.  At 36", 100lbs of force = 300lbs at the bolt.  etc., etc.

I weigh 150lbs, so if a sit on a breaker bar (galvanizd pipe) 36" distance from the stud center, I am appling 450lbs of torque to the lug nut.  I use a 48" bar so I do not have to apply as much force.  I also use a 3/4 drive socket set to ensure I am not stressing the socket set to much.

For the Chevy P30:
5 lug 9/16" stud single wheel torque =  120 Ft lbs
8 lug 9/16" stud dual wheel torque =  140 Ft lbs
10 lug 5/8" stud dual wheel torque =  200 Ft lbs

For Dodge:
M300 (Coned nut; 1969-1971) 5/8-20 stud = 175-200 Ft lbs
M300 (1971-1973), RM300, RM350 [M400] (Flanged Nut) 5/8-20 Stud = 300-350 Ft lbs
M375, RM400 [M500] (Double Lock nut) = 400-450 Ft lbs

Inch pounds
1 ft lb = 12 inch pounds (12 x 1) so 48 inch lbs = 4ft lbs (48 / 12 = 4)

School is now out and it is time to go camping

Dave

[Rickf1985]

I want to add something in here since it just happened to me. I just got new tires and when I came home I had to pull the rear tires to put on brakes. 6 of the 10 lug nuts on either side were loose!!! I am talking no9t a whole lot tighter than hand tight. NEVER think that just because it is a tire store that the lugs will be tightened correctly. I called them about it and you can guess what they told me. "They were all tight when it left here, they do sometimes loosen up when driving." Really? in ten miles? 12 out of 20 nuts? Not likely. That was just the rear. The fronts were not as bad but not tightened to 200 ft. lbs..

[M & J]

I just put simulators on ours and I had to use a 6' pipe on the breaker bar to loosen them. I then tightened the nuts using the same bar.

[legomybago]

Once more...a reminder NOT to go to the tire store Rick went to!!