Yesterday I had the coach at the shop getting some helper springs installed on the brakes among other things. The shop foreman called me and ask me to come by to look at something. Some of the wheel studs had pulled away from the hub as seen in the pic below. One is out about 1/4 inch but the others have a very small gap and some have no gap. I ask if we could just knock them back in and tighten the backing but, the shop foreman recommended replacing them. Knocking them back in and tightening them worked but the foreman still said it would probably be better to replace them, all 20(10 per side). Has anyone had this issue to deal with? I don't want to if it is not really necessary. The mothership only has 3 at $45 a piece. Meritor has some that are $55 but are emergency stock meaning I really need them and the must be overnighted , for 10 the overnight fee is $150 so you can see that if it not absolutely necessary and unsafe I don't want to replace them for economic reasons. Open to any and all opinions or suggestions.
Thanks in advance
Keith
Wow those are expensive! It looks to me like they have been over torqued to many times, and stretched. My opinion, torque them to what its supposed to be torqued and check them often.
Replace only the ones that pulled through, but have a couple of spares in case during the torquing another one pulls through.
Studs are (or should have been) pressed in, doesn't look like these were ever bottomed out. Could be they were and the backing nuts were never tightened originally???
Get the studs bottomed out (I would prefer a press over "knocking them in"), tighten the backing nuts and you should be good to go. Make sure those backing nuts are TIGHT and keep an eye on them for a while.
You won't stretch studs like that by over torquing them.
Ralph
96 U270
When I replaced a couple of mine last year I used the backing nuts to pull them through and seat them.
Agree with Ralph,they were either not tightened all the way or possibly the wrong ones,the threads look good,put some penetrating
oil on them and tighten them,there's no way they would stretch that much,the threads would give out.Do you have a part number for them,if so search for a better price.
I had the same problem back In February. I think MOT charged about $100 each to replace the stretched studs on my front end.
Damaged lug bolts (https://www.foreforums.com/index.php?topic=36164.msg342112#msg342112)
As I mentioned in the post, the front tires had been replaced a year earlier and the dealer accepted responsibility for over-torquing the lug nuts. They paid the entire charge which was close to $1000. Now I always watch how the lug nuts are torqued. See attached.
George
I'm at work now but yes I have a part number at home. No truck part place around here has them. One place I talked to said the came up as vintage, but they didn't have them. MOT didn't have any FOT only had 3, meritor was on back order except for the "emergency " stock
Keith
George, Herman Power put tires on my coach 2 years ago when I bought it but I had an issue on the road with one of then and replaced the steer tires this year, that is when one lug was noticed. So I'm sure Herman power would now say it wasn't their fault.
Keith
Keith... It might be worth a try. When I talked to them I was not even asked for proof that the tires were bought there. And it was the previous owner that bought them. I got the feeling that I was not the only person to bring this problem to their attention.
George
I would tighten the nut on the backside and pull the studs in and then get a depth gauge and determine whether the studs have stretched or not
The studs and matching backing nuts are proprietary to Meritor. I visited a big truck supply house in Knoxville, TN last year and looked through an entire Euclid catalog of wheel studs and never found anything with the same dimensions as the Meritors. And I later found out that Meritor owns Euclid, whose catalog I read.
As I recall there was a big selection of nuts, but I went with the matching Meritors as they looked better made than what was pictured.
The studs are becoming unobtanium!
Go to a local diesel rig tire shop and beat the crap out of prices quoted you.. I buy them by the box and don't have access to the last tiicket but I can promise that if they had of been that much each I would remember it.. True I buy a lot of tires from my vendor but I don't get that much discount..
Ok after reading traveling man post maybe these are "special".. I buy them for semi trucks and trailers so I will shut up until I have to buy any for the coach then you can bet I will be heard from again. I would be darn sure I couldn't buy them cheaper before paying these prices quoted crap that's robbery.
How do we prevent this from happening in the future?
I hate to pay for six new tires plus extras and then have to get out my torque multiplier to torque all the wheel nuts properly............in public.
The price quoted to me from meritor was 95.17 per pack of 2 and said I could get them cheaper going thru a truck parts house buying them from them. They gave some dealers local to me to do this. Their price was 55 but I didn't ask if that was each or the pack of 2. They were $80 or so at the mothership for a pack of 2 before my motorcade discount but they only had 3.
Keith
Have a look at the threads sticking out of the nuts on the backside. If the ones that are good have more thread than the bad ones sticking out, tighten the nuts as mentioned before in this post. If they tighten up then they would be good to go.
The amount of the stud protruding from the nut seems to be Different lengths . I would drive in the stud and re torque the nut . If the stud was stretched it certainly would not show on the backside of the nut .
Only 2 ways to prevent it Travlin' Man.. Stand and watch the kid torque the studs or torque them ourself.. Dam shame with the cost a man can't get proper work done..
It looks to me the nuts that pull them in have backed off just tighten them up and you should good to go.
The reason in my reply that they must tighten up to be good, comes from previous posts where the pulling force from the larger diameter lug nut actually pulled the threads out of the inner nut or inside threads of the stud. The stud's in question are all in a row and must be addressed. Your original posts states that the inner nuts tightened up, but because he knocked them back in I would make sure they are not stripped by torquing them.
Somehow, maybe by checking a new replacement stud, find the overall length of a new stud. Then measure the overall length of your studs. If your studs are longer than they used to be, bin them and replace them with new. Once you stretch the studs, you are into a no-man's land of guesswork, where the only thing certain is that the studs no longer have the strength they originally had.
On torque to yield bolts, when measuring the length, a micrometer is used. When that can't be done, so many degrees of rotation after an initial torque value is reached. Either way, torque to yield fasteners are one time only fasteners.
From other posts these studs strip the studs or nuts on the inside of the hub, before stretching.
Maybe loctite some new retainer nuts. For some odd reason, it seems as tho the tq value for the outer nut is higher then the inner retainer nut.
If the outer is over torqued then they will pull out.
Also ** if your bus has left hand threads , make sure that the tech knows that fact...
Maybe someone mentioned this, but my stretched studs were discovered when they could not torque them to 450 foot-pounds.
George
George, were they stretched, or did they pull through the nuts?
Don't forget the splines.
Craneman... good question and I really don't know the answer. I remember they are not easy to get out, that is for sure. Does the photo of the stud in my post show anything? When looking at that pic keep in mind that some damage may have been done in the process of removing the damaged stud.
George
hdff,
Pardon my French, but there's no way in hell the stud, top left, in the OP pic stretched that much. The back nut and/or stud are stripped, the stud is broken (unlikely), or the nut backed off. Take the nuts off the proud studs and inspect the threads of the nuts and studs. If the nuts are stripped, but studs are good, replace the nuts. If the studs are stripped or broken, get out your wallet. Either way, torque the back nuts to the proper spec. Watch "mechanic" like a hawk or, better yet, do it yourself. JMO
Whatever it takes to make it right. This is not an area to do a questionable "fix" on.
Your picture shows the stud stripped.
The inner nuts are 250#, the wheel nuts are 350 -400 or a little less greased. 450 or more with a nasty impact should pull the inner threads,every time. IMHO. 400# with a torque wrench should be the upper limit .
The splines only reduce the turning of the stud.
The splines are a manufacturing "cheat." Precision is expensive and both sides, the hole and the stud are less expensive to manufacture using splines to insure a press fit.
In this case, the shank of the stud has a straight knurl. Somewhat similar in appearance to splines. Splines are (normally) machined and/or ground. Knurling is a forming process (metal displacement), used for a variety of reasons. In the case of our wheel studs, the reasons given in the 2 previous post are correct, except that the knurl is intended to prevent the stud from rotating.