Front End Shudder

[megz]

Around 12 months my 110 developed a violent shudder at certain speeds, which turned out to be the panhard rod (seized bolt, bushes replaced).

The shudder has started up again, usually between 80 and 90 kph in 5th gear (doesn't seem to happen revving out in 4th). It feels like it is originates at the passenger side front wheel. If I slow down or brake suddenly it seems to fix it.

Any ideas what this could be? The shudder is violent enough to have to pull over. Could it be a wheel alignment? I'm getting a new set of tyres tomorrow so I'm hoping so.

Thoughts?

Thanks

Dave

[Phil B]

It could be the panhard rod bushes again. I found that anything other than OEM don't last.
I have heard that Superpro are also good but I have no personal experience with them.

Also check the wheel bearings and swivel pre load.

There are several posts on the subject. Just search "death wobbles"

Regards,

[Sly]

Remove some shims or change out the king pin bearings .......

[JDNSW]

It could be one of several possibilities, including the ones suggested.

Most likely a small amount of play in the steering or lack of damping at the swivel.

1. panhard rod - get someone to rock the steering back and forth while you check for movement of the axle assembly sideways relative to the chassis. Any movement here is an issue with either end of the panhard rod, or possibly the anchorage onto the chassis is loose. If there is no movement, this is not an issue.

2. Swivel preload. This needs to be checked according to the manual.

3. Tie rod ends. While the wheel is being rocked for #1, feel each tie rod end. Any free play will be immediately felt.

4. Wheel bearings. Jack up each front wheel - try to rock sideways and vertically. Should be no movement. If sideways, can also be tie rod ends, if vertical can be swivels, so check these first.

[86mud]

also check radius arm bushes. Fitting new genuine rubber bushes on the radius arms (both ends) to my 1998 130 recently transformed the ride.

[megz]

Thanks John, really appreciate the detailed message.

Dave


It could be one of several possibilities, including the ones suggested.

Most likely a small amount of play in the steering or lack of damping at the swivel.

1. panhard rod - get someone to rock the steering back and forth while you check for movement of the axle assembly sideways relative to the chassis. Any movement here is an issue with either end of the panhard rod, or possibly the anchorage onto the chassis is loose. If there is no movement, this is not an issue.

2. Swivel preload. This needs to be checked according to the manual.

3. Tie rod ends. While the wheel is being rocked for #1, feel each tie rod end. Any free play will be immediately felt.

4. Wheel bearings. Jack up each front wheel - try to rock sideways and vertically. Should be no movement. If sideways, can also be tie rod ends, if vertical can be swivels, so check these first.

[megz]

Good tip, thanks.


also check radius arm bushes. Fitting new genuine rubber bushes on the radius arms (both ends) to my 1998 130 recently transformed the ride.

[frogg]

When was the last time you changed your front toe setting?

When was the last time you:
1. Lifted the truck?
2. Changed the radius arms?

[megz]

Gday Frogg, thanks for asking these questions.

I've been a tinkerer for years and years but I've still got heaps to learn and questions like this get me researching and thinking.

- I haven't checked my toe setting but now I know what it is I'm going to check it.
- Lifted the truck? Do you mean has it got a lift kit? because no it's stock standard suspension.
- I haven't changed the radius arms in the 18 months I've owned the vehicle. Do you mean the bushes or the entire arm? How often/kms to replace when the vehicle is 90% on road?

Just had the vehicle come back from the shop to have some rear suspension work done and they reckon the pitman arm ball joint needs replacing (they didn't have a kit on hand). Reckon this could be the cause?

Dave


When was the last time you changed your front toe setting?

When was the last time you:
1. Lifted the truck?
2. Changed the radius arms?

[JDNSW]

Yes.

[AK83]

Swivel bearings and preloads are a PITA to check and do, so my preference is to check and do the easier stuff.
I had a similar death wobble(had to slow to 60k/h) recently in my D1 too.
In the past 2 years I've been changing/replacing stuff I know from experience that causes these issues, and I want my D1 to be gentle on it's tyres and driver too.
I know my radius arm bushes are all in good nick, panhard bushes a little dodgy(bolts slightly worn/slack, etc. so changed them.
I prefer Polys now(just previous experience), but anything new is good.
I've done all four tie rod ends, and I also got a new steering damper. This was all in the previous 18 months, then about 6 months ago, I got another bout of death wobbles.
Out of the blue.
Double checked radius arms, all good. But as a precaution I had plans to change them too.
When I fitted the tie rod ends, my drag link was worn inside the threads, and wheel alignment joint said they could move them.
Maybe the drag link .. got a new one, same problem(slightly less, but still there). Bugger!
On a whim, I thought get a new steering damper .. kind'a feels like it, but couldnt' possibly be .. it's a fairly new one, heavier duty(!!) got it from the well know company that uses a bull as it's logo.

Fitted the standard Armstrong(I think $50), non heavy duty damper ... death wobbles gone!

Still can't believe a basically new product, supposedly better/more durable .. caused me so much grief!
I still have it, it feels fine along it's travel, smooth operation no sudden slips/slack .. just crap quality!

So for the sake of 30mins work and whatever the cost of a std defender steering damper .. I'd say it may be worth replacing just for the peace of mind knowing it's not the cause.

And as for the pitman arm joint .... I'd change it to the D1 style drop arm with the hole instead, and use a good quality tie rod end instead(I did that on my RRC).
But, for sure, a half mm play in that will cause these issues too.

[JDNSW]

One of the things to be aware of is that you could have several problems - which together result in the wobble - fix any one of them, and it stops; but it will be back when the other issues get worse, and this time repeating the action that fixed it last time probably won't work!

[rar110]

Something easy to check for is loose gearbox mount bolts. I had the occasional horrid noise and this was the reason.

[frogg]

- I haven't checked my toe setting but now I know what it is I'm going to check it.
- Lifted the truck? Do you mean has it got a lift kit? because no it's stock standard suspension.
- I haven't changed the radius arms in the 18 months I've owned the vehicle. Do you mean the bushes or the entire arm? How often/kms to replace when the vehicle is 90% on road?


How ya going, Dave - thanks for the info - just trying to learn more about your setup :)

- The quick and dirty fix for bad front shudder, the kind that makes a person deathly afraid and goes away when you slow down is to increase toe out.
- Good to know on the lift - lifts change caster.
- The radius arm itself - some aftermarket arms can change caster as well.
- Not sure about how often to change the radius arm bushes, although I've seen trucks that seem to drive fine with some truly stuffed bushings.

I'm not sure that swivel bearing preload will cause the frightful shakes, maybe, but I've never seen it. A quick way of telling about the swivel bearing preload is if you slam on the brakes hard from 10-20 miles per hour, and you feel the truck almost changing lanes by itself, or if you feel the truck feel like it's wandering left and right on its own on the highway. If you have some more time, jack up the axle, grab the tire, and give a good push-pull top and bottom on the tire with two hands. If you can notice a small jiggle, it just needs some adjustment.