WTF?? Hub nut keeps getting loose.....

[87BrnRsd]

Ok, whats the deal with the hub nuts that like to loosen up on our trucks? My brothers 79 K5 with 10B front loosens up the inner front hub nut about once every couple of months. By the time any symptons are noticeable (the wheel moving from side to side), it has already started on the wheel bearings which then need to be replaced.
I rotated the tires on my 87K5 on saturday to find that my wheel wobbled in and out. I figured it was the wheel bearings. I got into the hub, and found that the hub bolts (the ones that require the special 4 prong hub socket) were about 4 turns loose. I had to replace the bearings and races and re-assembled the hub. I did make sure to tighten the inner nut down until it couldnt get any tighter without making the wheel unable to turn, then I tightened the outer nut the same way.
Yesterday, 3 days after I did the hub, the hub nuts had already loosened up again. WTF!!! Now it probably needs new bearings and possibly races again. Its not that big of a pita to do, but it requires money, of which I dont have a lot. So have any of you guys ever noticed this problem before? Does anyone know what causes it? Thanks.
-Harrison

 

[6.2Blazer]

Are you putting the lock rings on???? With the lock rings installed correctly it's pretty much impossible for the nut to loosen.

The next issue may be that if you tighten the inner nut too much, than you are burning up the bearings................trashed bearings will also get play in them and have similiar characteristics to a loose hub nut.

 

[sweetk30]

i have found lots of cheap nut sockets out there that when used actuly brake off the inner nut lock pin. then when you think its locked in it realy isnt.

and you need to get the specs for this. i think there is a spec for the outer nut to the inner nut with washer inbetween.

what size tires? you might be eating up bearings with to big a tire on axle.

 

[HarryH3]

The torque spec for the outer nut is around 160 ft/lbs for the later rigs with auto-locking hubs.

There also should be some endplay in the bearings when properly installed. Check the service manual for specs. I think it's something in the .008-.015 range.

 

[spincast375]

I have the same problem. A buddy who has had a Blazer much longer than I, tells me with the oversize tires he always had the problem. We just routinely check the lugs: once a week when mine is driven daily.

 

[Jonny-K5]

how much are you torquing down the outer nut?if installed properly w/ lockring, it should never come loose. ive never had a problem with mine , could also be causs your running 37s on there, componding improper setup.

 

[79Beast]

Several things. It sounds like you are putting way too much preload on the bearings. The hub should spin easily. Next, you didn't mention the lockplate. Try 2 new spindle nuts and a new lockplate. If you put just enough preload on the inner spindle nut to eliminate all in and out play but still have the hub spin freely then make minor adjustments to it so that the tit on the inner nut lines up with a hole in the lockplate while at the same time the tab on the lockplate is in the groove on the spindle, then torque the outer spindle nut to 150 ft/lbs you shouldn't have a problem. Running huge tires on any axle will wear the bearings faster, but 3 weeks shouldn't be long enough to notice.

 

[HarryH3]

It sounds like you are putting way too much preload on the bearings.... If you put just enough preload on the inner spindle nut to eliminate all in and out play but still have the hub spin freely

There should be NO preload on wheel bearings. None, zero, zip, zilch, nada! Check the factory service manual and you'll find that there is an endplay spec. There is supposed to be just a little bit of slop there when the bearings are cold.

 

[CyberSniper]

Well, are you putting it together with the lock washer then torquing down the jam nut?

I only put the jam nut on at about 70ftlbs (about half what most people do) and have never had one come loose.

 

[87BrnRsd]

The next issue may be that if you tighten the inner nut too much, than you are burning up the bearings................trashed bearings will also get play in them and have similiar characteristics to a loose hub nut.

This isnt the case. The bearings are fine and so are the races. I got it in time that the loosened nut and play in the hub didnt kill the bearings. But I am pputting new bearings in anyways.
-Harrison

 

[1-ton]

He still has not responded to the most important piont in the thread (whether they are using a locking ring or not).

 

[87BrnRsd]

Yes, I did put the lock ring on and it was installed correctly. I just finished putting the new bearings in and got it all back together. I guess I will find out how long it works for this time.
-Harrison

 

[bigred81]

Check the inner nut to see if it still has the little metal piece that locks the lock ring to the inner nut. I have had some come in the shop with this metal piece broke off and the wheel was still tight. If it happens again I bet that is your problem.


bigred81

 

[BlueBlazer]

You are tightening the bearings too tight, probably not lining up the pin in the inner nut with the lock ring, and probably not tightening the outer nut tight enough. Get a manual and learn to do it right before you kill somebody.

 

[87BrnRsd]

Great advice..............NOT
I believe I figured out what the problem was. I changed the wheel bearings 2 years ago, and the hub nuts just loosened up last sunday. When I put everything back together and it only lasted till wednesday, I figured there was something wrong with the nuts. I put it back together today and I thought it was fine. Then I realized that the nipple on the inner nut was not quite long enough to go through the hole on the lockwasher. It looked like it went through, but upon closer inspection I could see that it broke off. So I took it apart again and bought a new nut, and whalla. Good as new.

I have spent many hours working on my truck by myself. I have put a lift in, re-done axle gears, hubs, put in more than one engine, installed a few trannys and t-cases, and done pretty much everything else to my truck myself. Your advice doesnt help when you say look at a manual and do it right....I know how to do the damn job.....Keep your advice to yourself....
-Harrison

 

[BlueBlazer]

Well if you are so damn good then why do you need to ask us for advice? Ill keep my advice to myself if you keep your questions to yourself.

I did make sure to tighten the inner nut down until it couldnt get any tighter without making the wheel unable to turn

Judging from this statement you DO need to read a manual.

 

[BadDog]

Lets keep it civil guys. Particularly you 87Brn. You asked for advice, you got advice, whether you choose to accept it or believe it is up to you. But there is no need to talk in such a manner to someone who is trying to help you.

 

[87BrnRsd]

Well if you are so damn good then why do you need to ask us for advice? Ill keep my advice to myself if you keep your questions to yourself.



Judging from this statement you DO need to read a manual.

I asked for your advice before I tore down the hub for the second time. I asked because I figured it was a common problem because my brothers hub does the same thing. Once I realized that the nipple was broken off of the inner nut, it became very apparent that it wasnt my fault it came apart. Your advice about getting a shop manual and doing it right obviouslt did not help one bit. I did it right, but I couldnt see the first time that the nipple wasnt completley connecting through the hole on the lockwasher. When I took it apart the second time, a closer inspection (to find the cause of the problem) revealed that. Therefore, your advice was not helpful one bit.

As far as how I tightend the inner nut, how do you recommend I tighten it? You said get a shop manual because I wasnt doing it right. From what everyone on here has said, and from my previous experiences with hub nuts, you tighten the inner nut as tight as possible, without making the hub hard to turn. I have always done it this way and it has always worked fine. I put this hub together over 2 years ago and it only came apart when the nipple broke off. I put it back together without realizing this, and it came apart in 3 days. I bought a new nut, and I am willing to bet it will hold untill either the nipple breaks off again, or I take it apart to change a shaft. This also explains why my brothers does the same thing. He has had to do this several times as I mentioned before, but he has never bought a new inner nut. That should solve his problem.
-Harrison

 

[87BrnRsd]

I may have overreacted when I made my first statement to you. But, when your advice is "get a shop manual before you kill somebody" I was highly offended. First of all, I own 3 manuals. Chiltons, Haynes, and the very rare and very complete gm factory service manual. Second, it is physically impossible for the hub to just fall off while driving due to the inner nut being loose. Before that happens, the inner bearings would seize, which would destroy the spindle, which would be impossible not to notice while you are driving. I spend a lot of time on my truck to make sure it is completley safe to drive. I drive it daily to school, work, and anywhere else I need to go. If there was anything I did on my truck that I was unsure of, I would make absolutely sure it was done the right way before taking it back on the road, becasue the person I would kill would most likely be myself. So, when I asked for your advice, I wanted your advice. What I didnt want was someone telling me I was going to kill somebody because I didnt know jack **** about working on trucks. Thanks.
-Harrison

 

[BadDog]

I think his point about the manual was that there is a actual measured procedure for tightening those nuts, and it's not "tighten till it does not want to turn". Although "kill someone" was a stretch, incorrect adjustment *could* lead to a seized hub and loss of control, therefore injury/accident.

Thank you for restating in a civil manner. Nothing wrong with stating your mind about the perceived quality of help/advice, just keep it civil. I find that often times I am glad that I temper my responses when I eventually realize that the initial poster had more to offer than I first realized, even if not stated in an ideal fashion...