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Old 9th July 2010, 08:19   #196
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Originally Posted by DKG View Post
Gogi I've discovered a brilliant solution to the death wobble - Radial Tyres !!

Deepak - I've had death wobble in my CJ3B that had 235/70 R 16 radial tyres.

I believe death wobble will be present in a incorrect suspension / steering setup!
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Old 9th July 2010, 08:39   #197
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Dear Deepak / Gogi / Vikram - "death wobble" or "steering shimmy" as it is correctly called is due to generation of an uncontrolled force couple resulting out of excessive clearance in the top and bottom king pin bearings. It is extremely important to shim these bearings for correct design pre-load. There is no other reason. I had done this analysis as part of my dissertation in M&M when I was a trainee in 1980. I wish I had the hard bound report, I would have shown you. I gave it away to my college library after passing out (VJTI - Mumbai University). The king pin bearing preload must remain between 5.5 to 7.2 kg with the oil seals and axle shafts removed, it is to be measured by attaching a spring balance in the steering knuckle hole which holds the tie rod. Unfortunately, I had also proved thst if this value is not set correctly (which is what happens in 99% of the cases), the life of these bearings gets affected. You need to correct accordingly.

Best regards,

Behram Dhabhar
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Old 9th July 2010, 08:59   #198
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@ DHABHAR. BEHRAM have sent you PM. off topic will you be coming for the goa round of great escape?
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Old 9th July 2010, 10:16   #199
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Hey i had the death wobble when i bought the 3B, my mech worked on the steering, suspension including the king pin stuff and i haven't faced an issue for the last 900 odd kms after the job. Am running NDMS also and only thing i had done is some greasing for these parts in between.
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Old 9th July 2010, 11:18   #200
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Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear Deepak / Gogi / Vikram - "death wobble" or "steering shimmy" as it is correctly called is due to generation of an uncontrolled force couple resulting out of excessive clearance in the top and bottom king pin bearings. It is extremely important to shim these bearings for correct design pre-load. There is no other reason. I had done this analysis as part of my dissertation in M&M when I was a trainee in 1980. I wish I had the hard bound report, I would have shown you. I gave it away to my college library after passing out (VJTI - Mumbai University). The king pin bearing preload must remain between 5.5 to 7.2 kg with the oil seals and axle shafts removed, it is to be measured by attaching a spring balance in the steering knuckle hole which holds the tie rod. Unfortunately, I had also proved thst if this value is not set correctly (which is what happens in 99% of the cases), the life of these bearings gets affected. You need to correct accordingly.

Sir, You are 100% right. The Kingpin shimming is very important even for accurate steering feedback etc. As you are the professor, can you educate us on that? A separate thread is welcome too.

I faced these issues many years ago and had to meet an expert who did the job in 2 days flat!!

Half the gypsy guys would not even resort to power steering then!!
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Old 9th July 2010, 16:20   #201
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Quote:
Originally Posted by Jaggu View Post
Gogi get the timing checked too and next time am flicking this plug wires, looks super kewl
Already done sir. Was perfect!!

Quote:
Originally Posted by DKG View Post
Gogi I've discovered a brilliant solution to the death wobble - Radial Tyres !!
Deepak the two videos i have posted courtesy Youtube, show vehicles with Radial tyres on them. NDMS is not the lone reason for the Death wobble it has to do with the Kingpin, Steering geometry which has been explained by Behrambhai in the above post.

Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear Deepak / Gogi / Vikram - "death wobble" or "steering shimmy" as it is correctly called is due to generation of an uncontrolled force couple resulting out of excessive clearance in the top and bottom king pin bearings.....
Spot on Behrambhai and thats the area im addressing right now.
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Old 10th July 2010, 15:55   #202
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Gogi Bhai: Good pics and amazing report. Arey you should look at writing stories for bollywood! Am sure you will get out amazing movies.

Was able to see you and your jeep recently and it really looks awesome. Patience has really paid off and happy to know your having a ball with it.

Organizers: Tejas, Pdev: Great show. The threads and pictures says it all. Hats off to you guys.

@DKG: Which are those tires on your jeep? Looks awesomely brute. Made me remember the tires which are there on the tiller! Same kinda treads. Your jeep looks gorgeous
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Old 10th July 2010, 22:57   #203
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While what you guys say is correct I noticed an occasional wobble on my car before the trip when riding NDMS and throughout the Bombay trip it was non existent, hence the conclusion that radials made a difference. Logically the radials have the same effect as a steering damper on account of superior lateral adhesion/friction

Quote:
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@DKG: Which are those tires on your jeep? Looks awesomely brute. Made me remember the tires which are there on the tiller! Same kinda treads. Your jeep looks gorgeous
These are front tractor tyres of R1 pattern 700x16 8 ply tyres from Speedway a company in Jalandhar. I got the idea for these when I saw a picture from the 50's of an American lady driving a Jeep with similar tyres on a farm.

Thanks, much of its appeal lies in keeping it stock and functional
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Old 13th July 2010, 00:44   #204
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Originally Posted by headers View Post
Half the gypsy guys would not even resort to power steering then!!

So Vikram, are you saying that by making this change to a stock gypsy steering, it would be much more smoother / effortless?

Cheers,
Raj
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Old 13th July 2010, 12:19   #205
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Old 13th July 2010, 21:21   #206
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Quote:
Originally Posted by Desmosedici View Post
So Vikram, are you saying that by making this change to a stock gypsy steering, it would be much more smoother / effortless?
Yes RAJ, I had this steering issue for 2 years before I attacked the Kingpin shimming issue. The Steering is effortless after that even while i run 235s

Cheers
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Old 14th July 2010, 00:54   #207
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Thanks Vikram, Thats a very good piece of advise that you have provided to all gypsy owners. No hassles of installing a power steering kit which might trouble you in future.

Cheers.
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Old 14th July 2010, 08:26   #208
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Quote:
Originally Posted by Desmosedici View Post
Thanks Vikram, Thats a very good piece of advise that you have provided to all gypsy owners. No hassles of installing a power steering kit which might trouble you in future.

Cheers.
The trick is in finding the right guy who knows what to do. As I mentioned before - Have gone to the extent of replacing my OE steering box twice, damaging it once etc etc.

Anyways, Sir Behram Dhabar is just a call away for you lucky guys!
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Old 15th July 2010, 17:09   #209
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Old 16th July 2010, 09:27   #210
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Swastikviji,
Thanks for sharing your video clip.
Noticed that, at 2.52 mins. of the clip, where on its final attempt...the white 3B is trying to climb up the canal, it could have rammed into the right side of the blue FJ which came in its direct path. The driver's reflexive distraction resulting in steering his jeep to the left seems to be the reason the 3B not making it. Were Marshall's present at this spot?
Regards,

Last edited by fazalaliadil : 16th July 2010 at 09:34.
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