Perentie 80 km/hr 'Death Wobble' Fixed

[Iwburch]

If anyone has been trying to solve a violent death wobble that cuts in at around 80km/hr, this solution may be instructive. Noting that there can be many culprits in the steering linkages, in my case three elements conspired:
1. Panhard rod bush on one end was frozen to the bolt - replaced both bushes.
2. Toe-out was out by 10mm
3.  Left front wheel was out of balance by 400 grams (rotated to the rear)

Total cost for what felt like a very expensive and dangerous problem: $210 

[alvin]

Wow... toe out by 10 mm, bloody hell!

Great on fixing the other stuff too.

Alvin

[DennisM]

I don't own a ex-mil 110, but have owned a 110 County Isuzu for the past 25+ years, and I always carry 2 panhard bushes, as they can and do let go/fail without warning, you were lucky that your vehicle was still able to be driven @ speeds up to 80kph, when the panhard bush lets go you will be in 1st gear doing 2<>5kph and you will really think the front end has fallen out from under you, anyway good work in keeping your vehicle on the road, the maintenance never stops, cheers Dennis

[Carzee]

A spare Panhard Rod can be sourced from a wrecker (part NRC9729 -stamped HRC117841) for up to $50.

The rubber bushes (part ANR3410) are about $45 total if you buy genuine.

[tona]

   JOIN THE CLUB, MY RFSV HAD THE SAME PROB , GOT THE SPARE OUT WHICH HAS GOT A NEW TYRE ON IT , TRIED TO GET IT BALANCED, GUESS WHAT ITS THAT FAR OUT IT CANNOT BE BALANCED, ITS OVER HALF A KILO OUT OF WHACK , ITS GONE BACK UNDER FOR A SPARE ONLY ,TONA,.

[BEARMAN]

   JOIN THE CLUB, MY RFSV HAD THE SAME PROB , GOT THE SPARE OUT WHICH HAS GOT A NEW TYRE ON IT , TRIED TO GET IT BALANCED, GUESS WHAT ITS THAT FAR OUT IT CANNOT BE BALANCED, ITS OVER HALF A KILO OUT OF WHACK , ITS GONE BACK UNDER FOR A SPARE ONLY ,TONA,.

Often you can fix this by breaking the bead on the tyre and rotating it 180 degrees on the rim and re inflating. A lot of tyres are out of balance from the factory and the rims are notorious for this also. When they line up you can get this massive out of balance thing.

[tona]

  YEP RIGHT THERE BEARMAN,I TRIED ALL THOSE TRICKS DIDNT WORK HAD TO PUT IT BACK UNDER ,TONA,. ,.

[Carzee]

 
Just to refresh the Panhard Rod issue and how it pertains to safety of life and limb, watch this restoration "How To" video from about the 40second mark showing a chassis with the Panhard Rod disconnected.

It really demonstrates just what mechanical function is performed -all day every day- by a Panhard Rod, and its no small wonder that such a stressed part can flog out the rubber bushes.... and when it has flogged out bushes it can be a real hazrad.

https://www.youtube.com/watch?v=9VCDqXqbCqg

.

[DennisM]

I have had the experience quite a few times over the past 26 years, they do tend to flog out and when they do (without warning) you will know about it, your speed will be reduced to a crawl i.e. 15kph and you will be doing all right if you can maintain it.
I got caught once, it all happened so quickly driving along at 100kph undulations on the road surface caused the front wheels to shimmy/shake, a light application of the brake fixed that and then it happened again and again getting slower n slower until the vibration was that bad, I had to stop n have a look, I couldn't see anything wrong at all, I thought it was how I had loaded the 110, but it just kept happening all in the space of approx 10 kilometers, then it was a very slow trip back into Singleton NSW (I was out along the Golden Hwy) about 1 hour in the wksp (mainly waiting for some-one to the job) from that day forward I have always carried 2 sets of panhard bushes and I only buy genuine ones in green packs not that blue crap or poly bushes, cheers Dennis
ps if you allow any oil to get on them, they deteriorate even quicker,,.

[AGAS 5]

I had one happen to a 6x6 Crew Cab. It had only done about 10K km at the time. I was happily sitting on 100 km/h and slowed to 60 when I came to a small town.... a few second later I got the death wobles. It was very difficult to steer as I slowed down.... I initialy used the gears rather than brakes.  Upon inspection it had totaly dropped out !!  I'd hate to think what would have happened if it occured at 100  8-/

Cheers

[303Gunner]

MY RFSV HAD THE SAME PROB , GOT THE SPARE OUT WHICH HAS GOT A NEW TYRE ON IT , TRIED TO GET IT BALANCED, GUESS WHAT ITS THAT FAR OUT IT CANNOT BE BALANCED, ITS OVER HALF A KILO OUT OF WHACK

Probably came back from the Sandpit with a souvenir Hi-Power stowed in the tyre.

[Chazza]

...
I got caught once, it all happened so quickly driving along at 100kph undulations on the road surface caused the front wheels to shimmy/shake, a light application of the brake fixed that and then it happened again and again getting slower n slower until the vibration was that bad, I had to stop n have a look, I couldn't see anything wrong at all, I thought it was how I had loaded the 110, but it just kept happening all in the space of approx 10 kilometers,...I have always carried 2 sets of panhard bushes and I only buy genuine ones in green packs not that blue crap or poly bushes, cheers Dennis
ps if you allow any oil to get on them, they deteriorate even quicker,,.

Makes me wonder if greasable bronze bushes would be better?

At least they would not fail without warning!

[Ivanalandy]

hi guys, the pitman arm.....i had to replace this as the old one had flogged out the internal spline on the steering box end and the bush at the panhard rod end. The new one is extremely hard to get on whereas the old one slipped off (and back on again) easily, though i know it is worn. Has anyone had any experience with this? I have the new arm in the freezer hoping that it is easier to get on when cold.

Sorry this is a little off topic, but at 80km/hr i have a 3-4" free play in the steering wheel which i am addressing.
cheers

[dodgeguy1942]

The freezer will shrink it and make it tighter

[Ivanalandy]

Confirmed dodgeguy, its now in the sun