Death wobble!

[BradleyDP]

I experienced last night at a 2 am ride - the Death wobble!
How to check for what caused this. Like to hear what you have to say on inspecting and repair.

[rocketeer]

In addition to the information displayed below you should consider tire balance, worn steering parts such as idler arm, drag link, tie rods, poorly adjusted sector shaft play, and weak shocks.



Larry

[aboyandhisdog]

Well, I've read and tried about everything around this affliction.  I have new shocks, replaced all of the steering components from the steering gear forward, and all front end bearings appear to be well lubed and adjusted.  My own take is that the "brinelling" is a RESULT of the death wobble and not the cause, however I understand this is not Willy's take on the situation.  This said, I do think that a "snug" adjustment of the drag link helps the situation, and of course, proper allignment is necessary.  The last time this happened I decided to try one more thing - I purchased a steering stabilizer from Rugged Ridge (through JC Whitney, as I recall) and I have not had the problem since (last spring).  My feeling is that the steering set up is just plain a poor design that allows front end vibrations to do bad things.  It shouldn't be this way, but it is.  I have heard that there is a one-piece tie rod set up available but I have not seen it.  I have heard that it works better.

[rocketeer]

The brinelling has been discussed before. It's caused by the pounding the upper bearing takes caused by the fixed kingpin design, not by the "death" wobble. A steering stabilizer is a bandaid that masks the problem, it does not fix it. I have never experienced the wobble on my CJ3A but then I rebuilt everything to factory specs. I've never come across a wobble that couldn't be fixed in all the years I've been at it. One of the biggest offenders is tires. Balancing often helps and becomes more critical when tires that were never meant for these jeeps are installed. Toe-in is very important as is tire pressure. Believe it or not worn spring shackles can add to the problem.

No such thing as a one piece tie rod setup for factory original steering. The idler arm pivoting on the crossmember precludes that.

Larry

[Frank]

Well, I've read and tried about everything around this affliction. �I have new shocks, replaced all of the steering components from the steering gear forward, and all front end bearings appear to be well lubed and adjusted. �My own take is that the "brinelling" is a RESULT of the death wobble and not the cause, however I understand this is not Willy's take on the situation. �This said, I do think that a "snug" adjustment of the drag link helps the situation, and of course, proper allignment is necessary. �The last time this happened I decided to try one more thing - I purchased a steering stabilizer from Rugged Ridge (through JC Whitney, as I recall) and I have not had the problem since (last spring). �My feeling is that the steering set up is just plain a poor design that allows front end vibrations to do bad things. �It shouldn't be this way, but it is. �I have heard that there is a one-piece tie rod set up available but I have not seen it. �I have heard that it works better.

My feeling is that the steering set up is just plain a poor design that allows front end vibrations to do bad things.  It shouldn't be this way, but it is.

It is not, something is worn or loose, or incorrect, Start @ the steering wheel and work your way down to the tire, and everything in between, and anything that it is hooked to,

Your will find wear, looseness at some point,, If you read the manual the steering information is quite in depth, over my head, but it is not the design of the vehicle, as mentioned if you set it up to factory spes  it will not wobble,

[Frank]

In addition to the information displayed below you should consider tire balance, worn steering parts such as idler arm, drag link, tie rods, poorly adjusted sector shaft play, and weak shocks.



Larry

Neat lil piece of propaganda there, �but it is just that, �There is a third element needed to cause brinnelling,,,

First off you may ask yourself how the looseness occurred in the first place ?? Did the shims shrink ?  No

 Brinnelling can occur with a properly adjusted bearing, caused by shock and vibration under load, �We used to see this on brand new trucks that where tied down to tight on transport,
The term we had for this type of bearing race wear was "Rail Roading"

So loaded shock load,, bearing under load, not moving for a period of time with shock and vibration, = brinneling,

Now if you have a bearing race that just has marks on it but cant really feel any indentation, there is another term for this, and it is caused by different foreign metal material, cant think of the name right now but has the same look as brinneling,



Frank

[Frank]

Fretting or False brinelling,

From here

http://frettingwear.com/2010/false-brinelling-is-fretting-occuring-in-bearings/




False brinelling is fretting occurring in bearings

When fretting wear occurs in bearings, it is referred to as false brinelling.  A bearing will experience false brinelling when it is not turning but subjected to vibrations of some sort.  Because the bearing is not turning, the grease or oil will be gradually removed from the ball or roller contacts ending in metal to metal contact.  Next wear takes place and the damage will cause the bearing to fail sooner after start up.

False brinelling is different from true brinelling.  Brinelling is caused by a large impact on a bearing which causes the rolling elements to leave large dents in the raceway.  False brinneling leaves a very similar wear scar, but it comes from a series of small impacts instead of one large impact.  False brinelling marks are usually wider than brinelling marks and there may be two marks for each roller because of the slip zones occurring on either side of the roller.

Bearings often experience false brinelling damage in an assembled machine in storage.  Only very small vibrations are needed for false brinelling to take place and usually vibration is not considered while deciding upon where to leave a machine.  If a machine it stored near where it will be used, it is very likely that there will be vibrations present from the machine it will replace.

False brinelling caused one of the most famous cases of fretting.  Automobiles in the 1930s were being shipped from Detroit to the west coast on trains.  During shipment, their storage location�a train car�experienced vibration leading to the failure of wheel bearings.  Unfortunately, similar mistakes have been be made many times since.

False brinelling causes bearings to fail because the rolling element and raceway come into metal-on-metal contact.  When the asperities touch one another both wear and oxidation take place.  This is bad on for several reasons:

[Frank]

True or False, ? Do these trunnion bearings have True or false brinelling ?


I am leaning towards False,

[rocketeer]

No brinnelling can occur with a properly adjusted bearing

Frank

That is complete and utter nonsense and shows a total lack of understanding of the leveraged pressures applied to an upper kingpin bearing. Even a properly adjusted bearing will experience that pounding and it will eventually lead to brinneling, period. The last thing this forum needs is someone throwing out misinformation when they really don't know what they're talking about.

Larry

[Gunslinger]

False brinelleing or True brinnelling, it doesn't really matter, you have to replace the bearings and the cups either way.  And Larry is right about shocks, steering set up, drag link setting, steering gears , it all matters and it all has to be right or the thing is going to give you some kind of trouble.  Start at the top and make sure its all right.  I just fixed one of those "just plain poor designs'.  It wandered all over the road and almost shook me out of the jeep, then I replaced the shocks and it was sweet music.
Todd

[Frank]

No, brinnelling can occur with a properly adjusted bearing

Frank

That is complete and utter nonsense and shows a total lack of understanding of the leveraged pressures applied to an upper kingpin bearing. Even a properly adjusted bearing will experience that pounding and it will eventually lead to brinneling, period. The last thing this forum needs is someone throwing out misinformation when they really don't know what they're talking about.

Larry

Egads Larry That is what I am saying !!!! "Even a properly adjusted bearing will experience that pounding and it will eventually lead to brinneling, period."

I should have put in a comma, sorry

What is described in your neat lil piece of propaganda is not accurate, like you say even a properly adjusted one will brinnel, So we are on the same page and it doesnt look like you agree with the neat lil piece of propaganda you posted either,,

Easy now Larry,,  Okay I fixed the post,

[Frank]

False brinelleing or True brinnelling, it doesn't really matter, you have to replace the bearings and the cups either way. �And Larry is right about shocks, steering set up, drag link setting, steering gears , it all matters and it all has to be right or the thing is going to give you some kind of trouble. �Start at the top and make sure its all right. �I just fixed one of those "just plain poor designs'. �It wandered all over the road and almost shook me out of the jeep, then I replaced the shocks and it was sweet music.
Todd

Well I am a scrounge if it is "False Brinnelling" and just leaves a visible mark, but you cannot feel any indentation, I run em, your new race will be false brinneled in no time as well,,

As Larry points out, So I dont get to excited about false brinnelling and re use them,

And I am not sure if I am buying into that neat lil piece of propaganda you posted about the steering knuckle oil seal acting as a vibration dampener,,, I dont know have to ponder that one,,,

But being that this trunnion bearing is a very slow speed bearing, the False Brinneling, No big deal, Run them , re use them, never had any problems, as long as there is no indentation you can actually feel,,

Complete and udder nonsense,, I like that, and that is what is in your lil piece of propaganda Larry, and you to agree with that, looseness does not need to be present to cause brinneling,,

[Frank]

No brinnelling can occur with a properly adjusted bearing

Frank

That is complete and utter nonsense and shows a total lack of understanding of the leveraged pressures applied to an upper kingpin bearing. Even a properly adjusted bearing will experience that pounding and it will eventually lead to brinneling, period. The last thing this forum needs is someone throwing out misinformation when they really don't know what they're talking about.

Larry

The last thing this forum needs is posting neat little propaganda posters that are inaccurate, by your own definition,

[F Bill]

Lets all be civil here, guys...please.

[Frank]

Lets all be civil here, guys...please.

Yes Bill, Sorry,

Sorry Larry, Your little cartoon got me thinking about the steering knuckle oil seal acting as a vibration dampener, ?? as they say,

I not sure about that, with a properly preloaded knuckle I just dont see it  moving up and down, Now what you can get is a Groove in the straight ahead position caused by looseness in the steering arms (I think) dirt collects near the wiper and acts as a grinding compound and chews into the steel,



But the fix here would be keep the tie rod ends and steering link in good working order, not allow the knuckles to work back and forth,