My Willys 3A and 3B Community
3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: BradleyDP on September 25, 2011, 07:19:22 PM
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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.
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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.
(http://i863.photobucket.com/albums/ab191/rocketeer_2010/Jeep/shimmy.jpg)
Larry
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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.
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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
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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,
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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.
(http://i863.photobucket.com/albums/ab191/rocketeer_2010/Jeep/shimmy.jpg)
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
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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:
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True or False, ? Do these trunnion bearings have True or false brinelling ?
I am leaning towards False,
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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
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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
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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,
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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,,
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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,
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Lets all be civil here, guys...please. ::)
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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,
(http://i739.photobucket.com/albums/xx39/backwoodsgoop/Wally%20Rig/011_WallyRig_GroovyBall.jpg)
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,
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Frank,
Maybe you would think about introducing yourself, you've got a total of 18 posts, Larry on the other hand sits on the right hand of the jeep gods as far as most of us are concerned. He's helped more us out of a problem on this page and the 2A page than most of us can count. You may be right, you may be wrong, I don't know, but I trust Larry and I don't know you? Sorry man, those are the facts.
Todd
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Frank,
Maybe you would think about introducing yourself, you've got a total of 18 posts, Larry on the other hand sits on the right hand of the jeep gods as far as most of us are concerned. �He's helped more us out of a problem on this page and the 2A page than most of us can count. �You may be right, you may be wrong, I don't know, but I trust Larry and I don't know you? �Sorry man, those are the facts.
Todd
Okay Todd,
I would have done a introduction but I didnt see a spot, So yes, names Frank, I operate a General Repair shop in North Idaho, a general grease monkey, specialize in Automatic Trannys, been @ it for 20 years,
I became interested in the subject of lubrication for these enclosed live steering axles after the local Toyota dealership Told me the grease was "Private"
So I began a quest to find this semi fluid goop that I had seen before in "Viscous Couplers" found in AWD transfercases, So long story short, I began posting about this "Private" grease on Toyota forums, letting folks know that the recommendation in the Toyota FSM not only was incorrect grade but incompatible from factory fill,
Well that did not turn out so good, and I have a list of Toyota bans from just about all of their forums, being the the entire aftermarket thinks this Old Man Willys goop is axle seal failure, even sell a upgraded seal to fix a problem that dont exist,
Now you may ask yourself what brings me to your lil Jeep forum ? Well I supply Novak Adapt with this grease, so not really supposed to sell it thru here, but more so just to talk about it,
You will find that I can be a good source of information, as it pertains to these axles,,
Thanks Frank
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(http://i739.photobucket.com/albums/xx39/backwoodsgoop/Screenshot2011-06-24at105844AM.png)
How very true this is, taken from a funny post from a Toyota forum, they think the Molybedendum *crap lithium chassis grease is "New and modern" and the best lube as per Toyota SALES,.
And the goop that is found in them is failure,
When it is filled that way from production, just like ol Man Willys did..
Every once and a while it comes up where I am asked Why dont old Jeepers know about this stuff, My answer, I think they forgot, But then again if you read Larry's comic strip the writer mentions all the info in a certain paragraph in the book, � �
Just like the grease deal,
(http://i739.photobucket.com/albums/xx39/backwoodsgoop/Screenshot2011-06-25at23953PM.png)
So the info has been in the books, as well as a bit of conflicting info, but with the help of Toyota, When Old Man Willies says "He filled the wheel bearings, he meant just that,
A liquid grease,,
As far as why on the next page it says a #2 grease for the wheel hub,,, dont know,, Maybee the same reason old Dodge books say both "Short Fiber grease" and #2 Multipurpose grease in the same book,
Clearly 2 different things, when investigated,
And Here is another good section from Old Man Willys Book
(http://i739.photobucket.com/albums/xx39/backwoodsgoop/Screenshot2011-06-25at21255PM.png)
So Todd the jeep gods also shined upon me and my 70 year old neighbors Dad had a Jeep bible, and in it, It explained to me what was going on in a 1988 Toyota,
To the T
And here is a lil more info,
http://www.backwoodsgoopinfo.com/goopBB/viewtopic.php?f=2&t=12&sid=2df629be479736d9947d28282d8fd1e1
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The Stability and proper function of the steering system, depends in a large measure upon correct alignment, and a definite procedure for inspection of the steering system is recommended. In so doing, nothing is overlooked and any trouble is ascertained in the shortest possible time. It is suggested that the following sequence be used:
a. Equalize tire pressures and level vehicle.
b. Inspect spindle pivot pins and wheel bearing looseness.
c. Check wheel runout.
d. Test Wheel balance and bearing adjustment.
e. Check for spring sag.
f. Inspect brakes and shock absorbers
g. Check steering assembly and the steering connecting rod.
h. Check caster
i. Check toe-in
j. Check toe-out on turns.
k. Check camber
l. Check king pin inclination
m. Check turning angle
n. Check tracking of front and rear wheels.
o. Check frame alignment.
Note If the steering gear to frame bolts are not properly torqued, they will eventually loosen during operation of the vehicle, Loose bolts will result in elongated bolt holes making the maintenance of the bolt torque difficult,
Okay thats what Old Man Willy,s has to say on the subject, pretty cool, after doing all that there should be no death wobble, and may very well be the section of the book the comic strip writer refers to,
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Brad:
After I replaced my original tired 3A springs with new American made ones, I developed the dreaded death wobble when I hit a bump while turning right. Scared the bejeezus out of me! A check of my front end alignment indicated that the geometry changed a bit after the new springs were swapped in. An old school front end alignment solved the problem.
No technical stuff from me! Used a really long straight edge and did it the old fashioned way. �;)
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Brad:
After I replaced my original tired 3A springs with new American made ones, I developed the dreaded death wobble when I hit a bump while turning right. Scared the bejeezus out of me! A check of my front end alignment indicated that the geometry changed a bit after the new springs were swapped in. An old school front end alignment solved the problem.
No technical stuff from me! Used a really long straight edge and did it the old fashioned way. �;)
Which is really is the only way to go, I would imagine that a New computerized alignment on these old rigs just wouldnt cut it,
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I'm no expert but I have noticed other bearings that end up in the smae condition as Jeep king pin bearings. The steering bearings on my Triumph motorcycle looked exactly the same after 25 years of pounding. Would there be any validity to the theory that these bearings do not make complete rotations like a wheel bearing so the load is always in the same area of the race resulting in the grooving?
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I'm no expert but I have noticed other bearings that end up in the smae condition as Jeep king pin bearings. The steering bearings on my Triumph motorcycle looked exactly the same after 25 years of pounding. Would there be any validity to the theory that these bearings do not make complete rotations like a wheel bearing so the load is always in the same area of the race resulting in the grooving?
Certainly, Basically 3 things are needed to make this sort of Race Damage, it does not appear to effect the Rollers or inner Race,
#1 Time,
#2 Pressure
#3 Vibration, And as you point out When the bearing is not moving,
This is What causes the Binnelling, eliminate any one of those 3 the bearing race will not show that wear,
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So For this Brinnelling reason which is common, causes looseness and death wobble it makes sense that it was the lubricant of choice for Jeep this is what they say about it
"Sodium base greases are fibrous and have a fairly high melting point suitable for antifriction bearings and other high speed centrifugal-operating conditions. It is an extremely good type of grease for use in heavy-duty applications taking shock-loading and pounding. Although sensitive to water, they have found their own niche"
From Here,,
http://www.shieldlubricants.com/indexphp/index.php?option=com_content&view=article&id=68:automotive-greases&catid=49:automotive-greases&Itemid=85
So right there, You can see the rational as to why it was used, it takes the Shock loading and pounding well, a "extremely good type of grease "
But Water sensitive,,
So if you go back a few posts you will see the caveat of rotating the wheels lock to lock after driving in wet and freezing conditions,
Dont want the Brinnelling and death wobble, use the correct type of Factory grease,