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Old 18th August 2008, 18:16   #1
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Angry The infamous Death Wobble

Hello All,

Those who are not visited this thread http://www.team-bhp.com/forum/4x4-of...hp-family.html; I have possessed my Jeep on last Thursday. I was driving her ever since I got the keys, for better understanding. And I am impressed, the way it response to throttle. I have a specific reason to start this thread, I think it may be helpful to other jeepers, as well and those who are planning to get one. Yes guys, my jeep is infected with the infamous “Death Wobble” aka DW (Thanks UBS Sir for the Tech Name and LOT of help for troubleshooting). BUT, I am not worried at all, as someone told in this forum, it’s all the part of the package. For those who doesn’t know what is a Death Wobble is all about, Read this Yucca-Man: Death Wobble and this DEATH WOBBLE.

In a nutshell, when you cruise around 60-65 km/h and hit a hump or any sudden change on the terrain like a sewage cover or some thing, the Jeep will start to wobble/or shake like hell, something like the entire front portion/tires will come apart. Man, it was so scary. Two times it happened to me, I slowed down and checked the wheel nuts, but there was nothing wrong. You will feel like your front wheel nuts has came out when this happens.

Now, I gave the Jeep to Vijay Auto this morning. Yeah that’s another experience all together with Mahindra. I had a warm welcome since everyone knows about my Jeep there. I checked the service history, and it was excellent. Again I did not want to take any chances so I told them to change all oils and liquids, so that I can keep a record from here on. About DW, told the mech to start looking at kingpin bearing, he also suspects the same. Then, steering box play, All U bolts, Wheel alignment and leaf springs. If I missed anything here please feel free to add it.
He told that he will deliver the Jeep tomorrow, or day after. I hope that I was correct on explaining the issue as he also had the same thoughts. Now the tricky part is to test drive it again after delivery. Its lil dangerous in Bangalore traffic, Let’s hope for the Best.

Sreeraj
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Old 18th August 2008, 19:29   #2
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I have felt this a few times as a learner driver on an MM540, i thought it was a normal occurence
Let us know how you fixed it.
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Old 18th August 2008, 21:22   #3
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I had experienced this in an OMNI once in darjeeling , my driver just jabbed the brakes hard for half a sec and the wobble subsided!
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Old 19th August 2008, 09:20   #4
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sreeraj

this used to be a weird occurrence in the old CJ 500 etc. a sort of wibbly wobbly feeling while braking before bumps. quite frightening especially on hill roads.

I think it is something to do with the front suspension. Also check wheel bearings, they might be responsible.

I remember this used to happen in our old cj500 around 1982-1983 but I was quite young so I cannot remember now exactly how the mechanics sorted it out.

maybe you should write to our fellow members ex670c and 4x4addict- they are both great experts on jeeps and I am a 100% sure they will be able assist you with a solution.

Last edited by shankar.balan : 19th August 2008 at 09:29.
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Old 19th August 2008, 10:00   #5
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Dear Mr.Sreerajuunnithan - the root cause is excessive axial clearance in the kingpin bearings. The workshop manual carries the complete procedure to preload these bearings by addition or subtraction of shims. The dealer should be able to sort this out as a matter of routine attention. At the same time, please get the wheel bearings checked as this phenomenon harms them for no fault of theirs. The tyres may need replacing if there are bad patches of wear on them. In new vehicles, there are no king pins. They are replaced by ball joints and this axle is called OEY (open ended yoke). Please do not think of swapping axles as steering geometry is different.

Dear Mr.Sankarbalan - thanks for your PM

Best regards,

Behram Dhabhar

Last edited by DHABHAR.BEHRAM : 19th August 2008 at 10:00. Reason: additional information
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Old 19th August 2008, 10:41   #6
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thanks mr behram!
hope it helps sreeraj

Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear Mr.Sreerajuunnithan - the root cause is excessive axial clearance in the kingpin bearings. The workshop manual carries the complete procedure to preload these bearings by addition or subtraction of shims. The dealer should be able to sort this out as a matter of routine attention. At the same time, please get the wheel bearings checked as this phenomenon harms them for no fault of theirs. The tyres may need replacing if there are bad patches of wear on them. In new vehicles, there are no king pins. They are replaced by ball joints and this axle is called OEY (open ended yoke). Please do not think of swapping axles as steering geometry is different.

Dear Mr.Sankarbalan - thanks for your PM

Best regards,

Behram Dhabhar
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Old 19th August 2008, 11:24   #7
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Behramji, does this happen on 340 too, how do I take precaution against this? Should I ask the service center to check excessive axial clearance in the kingpin bearings? My Jeep is still in the workshop, might as well get it done.
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Old 19th August 2008, 14:00   #8
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Okay, so what I had on the Safari post the Mysore-Bangalore speedbumps is technically known as the Death Wobble.

In my case it was the two lower arm wheelbolts that had lost their ball joints (ball joints with open-ended yokes as explained by Dhabhar).

Last edited by Steeroid : 19th August 2008 at 14:02.
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Old 19th August 2008, 14:34   #9
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Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear Mr.Sreerajuunnithan - the root cause is excessive axial clearance in the kingpin bearings. The workshop manual carries the complete procedure to preload these bearings by addition or subtraction of shims. The dealer should be able to sort this out as a matter of routine attention. At the same time, please get the wheel bearings checked as this phenomenon harms them for no fault of theirs. The tyres may need replacing if there are bad patches of wear on them. In new vehicles, there are no king pins. They are replaced by ball joints and this axle is called OEY (open ended yoke). Please do not think of swapping axles as steering geometry is different.

Dear Mr.Sankarbalan - thanks for your PM

Best regards,

Behram Dhabhar
Thank you very much Behram sir. I will communicate the same to Vijay Auto

Quote:
Originally Posted by Samurai View Post
Behramji, does this happen on 340 too, how do I take precaution against this? Should I ask the service center to check excessive axial clearance in the kingpin bearings? My Jeep is still in the workshop, might as well get it done.
Yes Samurai, it can very well happen to your Jeep as well. You can go to jeepthrills, -->files--->tech docs. you will find a doc created by Arka there about the this, you can proabably ask your mech to perform those steps. Just to make sure every thing is perfect.

--Sree--
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Old 19th August 2008, 19:27   #10
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i recently purchased an mm540dp here in coorg and i felt it twice.the entire jeep wobbled and shook like it would fall apart.

@ ShankarBalan: I had sent you a pm regarding the purchase.hope you read it.
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Old 22nd August 2008, 19:54   #11
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Just an update, the problem seems to fixed now by removing the shims and tighting it again. Did extencive test drive around 200 kms andd abused her a lot by jumping all the humps . But it did not re-apeared.

Thanks
Sreeraj
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Old 23rd January 2010, 23:05   #12
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Default Deadly experience with Jeep's death wobble

Hi,

I recently bought a CJ340 (1982) about a month ago. Initially when I bought the jeep, there was no wobble.Handling her was an ease and fun. But from few days, I started to experience wobble (aka Death Wobble -DW).Whenever I rode my jeep on slightly bumpy roads, she used to wooble. I had experienced DWs with other jeeps and hence neglected this as an usual phenomeon with jeeps. But todays experience was nerve rattling, this is the reason I am starting a new thread (other threads on DW : http://www.team-bhp.com/forum/techni...th-wobble.html (The infamous Death Wobble)). I was driving my jeep over a flyover at around 40kmph and suddenly my jeep started to wobble violently and started to drift towards left. Controlling her was difficult. Eventhough I slammed the breaks to slow her down so that there would not be any more wobble, jeep's left tyre still grazed the walls of the flyover. This got on my nerves as, if the jeep was at any higher speed, it would have climbed the flyover walls and I would have not been writing this thread. After getting the jeep to stand still I tried to move her, the wobble was still there and after around 500 mts I could not steer the jeep.After examining the wheels I found that the nut that holds and connects the tierod with the left wheel's knuckle arm was gone and there was no linkage between the steering wheel and the left wheel (there was no spilt pin to lock it in the 1st place). I had to wait for my mechanic to arrive with a spare nut. In the garage, my mechanic fastened all the tierod nuts and locked them with split pics. He also tightned the shims. The wobble seems to be temporarily gone. I know there are still a lot of things that needs to be examined and replaced/serviced if necessary (like shims, kingpin bearings, tierods, ball joints, etc). But I need to know why I lost the tierod nut was it due to the wobble or was it loose in the first place and caused the wobble. Anyway I am not
going to give up driving jeep with this incident. But this thread might add to some more thoughts/discussions on the DEATH WOBBLE.
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Old 23rd January 2010, 23:36   #13
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Satish, I merged the threads since there was no reason to have another thread.

First, CJ340 was made between 1989-1994, CL340 was made between 1995-1996, CL340 Classic was made between 1996-2000. So we can be sure your Jeep is not CJ340, it could be CL500.

Second, your guess may be right, you lost the nut because of the death wobble, what happened after is not death wobble. Death wobble goes way once you slow down. I too have had death wobble, so I know the feeling. Not a good idea a live with death wobble, whenever you experience death wobble, go to your mechanic ASAP and get everything checked, tightened, etc.
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Old 15th October 2013, 11:51   #14
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Default Re: The infamous Death Wobble

Hi Guys,
This was originally posted by UBS or Suresh Stephan on jeepthrills

Problem:

Wobbling of the front wheels.

This is quite common in Jeeps - because the suspension and steering linkages are very long and a little fault gets magnified in to a big wobble - the mechanics call it "BUBBLE".

In most of the ladder construction chassis, the vehicle weight is reached to the spindle via, springs, hangers, kingpin, and so on. The weight falls on the spindle from behind, and not even from above. Imagine if the tilt of the spring seats is disturbed due to wear n tear, then it delivers the weight at a different castor angle, which is factory set. The stability of the front axle is sensitive, and any jerk or bump can cause an imbalance.

There are a number of contributing factors - single or in any combination. It is recommended that when attending to one, all should be looked at. Because, here, the labour generally works out to more than the parts and the hassle of getting stuck in the middle of nowhere.

Brought on by:
High speeds.
Hitting a bump on the road.
Sudden manoeuvres of the steering wheel.
Immediate action to be taken:
Slow down.
Turn the steering wheel from one extreme of the free play to the other alternately - but don’t go swerving all over the road.
How to avoid the problem (without repairs):
Drive below the wobbling speed.
While driving keep moving the steering wheel from side to side - that is from one extreme of the free play to the other - the vehicle should not swerve.
If you have freewheeling hubs engage them.
In very extreme cases using 4 X 4 loads the front wheels and stops the wobble. But this is a last ditch resort as driving on hard surface in 4 x4 is a big No No.

Wobbling is a symptom of a greater malaise - it is not the problem. By fitting this you will never know of the real problem till it is too late.
However, A steering stabilizer can be added if one needs to enhance the
damping characteristics of the steering system. Useful for off-roading
where bumps that would normally cause an erratic motion of the
steering wheel would be dampened a great deal, leaving the driver in
better control i.e. reduces the effect of bump steer. It enhances the self-correcting tendency every steering system has i.e. especially useful when coming out of corners - usually attributed to the caster angle! Sometimes, it becomes necessary when using fatter tyres than normal. Therefore, unless one makes a conscious decision to use a stabilizer, it would mask genuine problems with the vehicle.

Troubleshooting:

Wheel nuts: check for looseness.
Visual inspection of suspension for any signs of loose bolts etc.
- U clamp bolts on road springs.
- Shackles and hangers.
- Brake plates.
Wheel alignment - jeeps wobble due to miss alignment only when the alignment is way out and is really visible to the naked eye. However alignment should be checked to avoid uneven wear on the tires - off reading really knocks the alignment out.

Wheel balance - not a problem really. Unless the rims are very badly damaged. Balance causes wobble at high speeds that we generally don't hit - 90 kemp or there about.
Hold the steering wheel firmly and shake - side to side - if there is any play - bushes have to be changed in the steering column.

Hold the steering wheel firmly and shake - up and down - if there is any play - the steering gear box has to be attended to. Reducing the play with the adjustment bolt on the box helps.
When was the last time that the whole suspension system was greased (like during water service)? A good greasing fills up the joints and eliminates minor wobbles too.

Check shockers - mounting etc - one good one and one bad one causes this problem too. Always change both at the same time.

Now, support the chassis at the front end with 2 stands so that the front wheels are off the ground and the suspension system is free, there should be no jacks anywhere else. Now:
Hold a wheel from the top and bottom and shake - if there is play - problem in the king posts - bearings or shims - open and check - replace bearings or tighten shims by removing a few.

Definitely repack the grease.

Repeat for the other wheel.

Hold a wheel from the two sides and shake - if there is play - problem in the axle nut, wheel bearings or knuckle kit - open and check - tighten axle nut, replace bearings or replace knuckle kit. Definitely repack the grease.

Repeat for the other wheel.

Stand in front of the jeep. Look at the bell crank - it is an 8" long metal cylinder on the driver side chassis frame below the radiator. The top arm (drag link) goes to the steering gear box.

The bottom arm to the tie rods. The drag link can be seen by opening the bonnet. Ask somebody to turn the steering wheel from side to side. Both the arms should move smoothly. There should be no jerks or play - at the bell crank end. If there is, the bushes in the bell crank have to be changed.

Drag link: Both ends of the drag link have adjustable screws to reduce the play. Grease and tighten.

Steering gear box: Grease and adjust play. Check bushes for wear.

Tie rods: Looseness and play.

Take a long rod and put it between the chassis and leaf springs vertically and lever the 2 - any play in the bushes and shackles and hangers is clearly visible. Attend to as required.
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Old 15th October 2013, 20:32   #15
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Default Re: The infamous Death Wobble

Hi,
How likely is the Thar CRDe to get a death wobble?
Any other (common In India) vehicle which has this problem?

Regards
Sutripta
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