What Shock absorbers to use?

[Patrick M]

Hi Blokes,
I have just recently discovered a problem while driving my RRC on a country bitumen road, the shockies that I have fitted (Koni) have no way of controlling axle hop when going over a very moderate depression in the bitumen, anything over 75Kph starts the axle hopping about 3 to four times and shakes the old girl to the point where it is extremely uncomfortable for any passengers inside the cab. If I try to negotiate a sweeping bend in the road and a depression is found with one or more wheels the old girl just literally hops her way around the bend (very unnerving).
The model number of the shocks are 8420 1190spx Rear and 8420 1181spx on the front.
The springs are from Rangie Spares and set to a height of 50mm above standard while carrying 250-300 Kl/gms of weight. The front springs are set to a height of 40mm above standard while carrying the extra weight of a steel bullbar.
These springs are carrying this weight perfectly as have all the other springs I have purchased from Rangie Spares.
Has anyone else had a similar problem and how did you get over it?
At this point in time I am ready to ditch the Koni's and replace them with Bilsteins from Rangie Spares but thought I might get some input from someone who may have had a similar problem.

[rick130]

Check the shock rubbers first, any wear there will allow undamped movement.

If they are ok get the Koni's revalved and rebuilt.

Proven Products in Albury or Toperformance somewhere in Melbourne can do it.

Actually, is it the front or rear axle?

[Patrick M]

Hi Blokes again,
a couple of things I should have mentioned in my first thread,
the whole suspension system is brand new and only has done a couple of thousand Kay's at the most and do mean "new" every bush and bolt etc has been replaced.
I should also mention Rangie Spares did not supply the shocks that I wanted as they were out of the Bilsteins at the time of this upgrade and I purchased the Koni's my self from a local supplier.
Thanks Swaggie for your input I can fully appreciate the problems connected with a chopped out shockie bushs, I have had heaps of them in the past but this is much worse than that.

Regards:-[bigsad]
Patrick M

[DAMINK]

Tie rod ends?

[Patrick M]

Hi Blokes,
Another thing I should have mentioned in my first and second threat was that all the steering has all been done as well, new ball joints, S/box rebuilt etc, etc.

[Vern]

Toe out? Swivel preload? Panhard bushes? Rear control arm bushes?

[rick130]

If they are new it won't be the shocks.

To add to Damien's list, wheel balance can do it too, as can a faulty steering damper.

[Patrick M]

Hi Blokes,
I probably should have mentioned in my first, second and third thread that the tyres are brand new and balanced properly. I thought that it might be the steering damper but the problem comes from the back as well as the front. "Axle Hop". I reduced the tyre pressure in the front by 7psi and that improved it a bit, but it's still there. Going from that rate of pressure reduction I would have to be down to about 18 or 20psi before the problem goes away which is not helping fuel consumption or tyre longevity. I normally run them at 32-35psi depending on the conditions.
Sorry blokes all that you have mentioned has been done with the suspension/steering rebuild.
Yep, keeps coming back to the shockies.
Thanks Blokes.[bighmmm]

[Phil B]

Before spending your hard earned on more shocks why don’t you try taking the front shocks off and see if it changes
By the sound of it you should know immediately if the shocks are the problem

[Phil B]

Don’t buy new shocks yet.
Just re reading your post those are symptoms of the “death wobbles”
Just google “death wobbles “ and there is lots of advise to repair it.
I had similar issues and it was the swivel preload to low and the panhard rod bushes. Use only OEM rubber bushes IME

[strangy]

Well, since everything has been "done" its time to take it back to those who "did it" because it hasn't been done right.

[Odysseyman]

Hi Patrick

You say that the springs fitted to the car are taller and designed for a heavier load. If you are using Koni’s standard replacement (heavy duty) shocks for your vehicle then I have a couple of questions.
Did you have them revalved to suit the heavier springs?
have they been matched to the spring length?

If you have only have their replacement shocks, they are only designed and valued to suit standard (original) springs in the car.

You MAY be able to get around your issue by adjusting them (and do this only if you know how as it is all too easy to unscrew the foot valve with the result that they will need to be rebuilt at your expense). Sorry, I hope I’m not telling you stuff you already know...

The adjustment on Koni shocks only affects the rebound damping and not the compression damping. Given that you have heavier springs I don’t see this as a major issue, as you are wanting to better control the rebound of the springs, from what you have described in your original post.

There are about 5 - 5/2 half turns of adjustment and in your case I would probably adjust them to about half way (about 2-3 half turns) and see what difference that makes. If the symptoms don’t improve once you’ve done this then I would look at revalving them rather than adjusting the rebound even harder. Adjusting them harder could result in binding up your suspension travel and make the ride and handling even worse.

Having them matched to the length of your springs is less of an issue given your symptoms but you do need to be sure that they don’t bottom out or top out before your suspension hits the bump stops or reaches full droop otherwise you run the risk of destroying them. Some manufacturers design their vehicles’ suspension so that the shocks perform the task of limiting suspension travel but it’s a less than ideal design in my opinion.

Cheers

David

[DoubleChevron]

If its the death wobbles.... I fitted a new rubber bush kit..... and didn't even get 1000km.... out of the panhard bush before it was aboslutely destroyed. The car was near undrivable above 80km/h....

The cheap rubber bush kits are ****house. Avoid at all costs.

seeya,
shane L.

[loanrangie]

Check the pitman arm nut and I would recheck the hub bearing and swivel pre loads.

[350RRC]

Check the pitman arm nut and I would recheck the hub bearing and swivel pre loads.

Absolutely, they're the main simple things that would cause this if everything is 'new'. The pitman arm nut can seem tight but there can be a lot of play.

DL

[Patrick M]

Hi Again Blokes
Thanks to all of you who offered to help me find a cure to my problem, I very much appreciated it, a lot of the suggestions to fixing the problem were not the answer but the fact that they were mentioned made me re-think and also re-check everything that I had done to the old girl however when Phil B mentioned the "Death Wobbles" and posted a link to look at I did so and thought about it all once again and realized that the only thing I had not done was replace the steering damper, so off it came, testing of it proved it was stuffed and justifiably so as it was probably the original unit making it thirty two years old.
I tried to locate a new Bilstien unit to replace it with (I have used them before with good results) but I was not happy paying $260 including freight to WA for one. I dithered around for a coupla days trying hear and there then gave up on it a bit for a while to ponder my next move as far as procuring one was concerned, when by chance, I was looking around my shed for something else and noticed a Bilstein damper mounted on a fullly equipped front diff housing complete with Maxi Drive Lockers and axles, which I had obviously forgotten about. I took the damper off, bench tested it (it was good) gave it a clean up and re-paint, mounted it to "Vilet", took it for a test run and guess what "perfect" no more "Death Wobbles".

Regards and thanks:-
Patrick M[bigrolf]

[timax]

Sounds like you have a great shed!
Nice list of cars also and this one with new everything also sounds like a great car.
Any pics?

[Patrick M]

Sounds like you have a great shed!
Nice list of cars also and this one with new everything also sounds like a great car.
Any pics?
It's alright but not what I would really like, it has to do the job and I do have a coupla interesting rigs but nothing like what I used to have.
But your harum sounds interesting.

[edddo]

I would have thought that the 'death wobble' should not be caused by or dependent on your steering damper function.
A tight steering damper may well mask it but the underlying issue could still be there.

[Patrick M]

I would have thought that the 'death wobble' should not be caused by or dependent on your steering damper function.
A tight steering damper may well mask it but the underlying issue could still be there.

You may be right but whats to say Land rover didn't put them on originally to do the same thing (hide a "Death Wobble" problem even when everything was brand new? Apart form that while re-building the old girl everything such as swivel pin and wheel bearing pre-loads have been done, everything as I have mentioned has been up graded, the only thing that was overlooked was the damper. Even the brakes were completely rebuilt the calipers have new pistons new seals new rotors and more. Actually that was an interesting one when I pulled the old cylinders out of the calipers some were blocked up with heaps of gunk rendering the primary and or secondary circuits to a minimum of their actual capabilities. Rebuilding them made a huge difference.

[RobMichelle]

I had a patrol with same symptoms I also replaced everything with new front and rear parts only thing not replaced was dampener, once replaced all was well again, so dampner definitely stops the death wobbles.

[benignbrent]

For me the best shock absorber is Bilstein 24-186742 i'm using it with my car. if you are looking for a shop for car mods australia check out Karl Knudsen Automotive | European Car Service Centre,Chatswood (https://www.karlknudsen.com.au/) they have a vey great selection and pretty affordable

[DiscoMick]

I had never considered Pedders until a relative recently put a set of their shocks on his 80 and they cured his death wobbles, so I'd give them a go in future.

[Tombie]

I had never considered Pedders until a relative recently put a set of their shocks on his 80 and they cured his death wobbles, so I'd give them a go in future.

He will fit another set soon if Pedders are like they always have been in the past.

All it means is he had worn shocks / bushes..

[DiscoMick]

He certainly did after 10 months on the road, towing a camper, seriously overloaded and pounding up the Gibb River Road to Darwin.

[AK83]

I had never considered Pedders until a relative recently put a set of their shocks on his 80 and they cured his death wobbles, so I'd give them a go in future.

I'd reconsider this too(as Tombie suggests).
I was rushed to get a steering damper for my D1 over the holiday period, and they were the only place open on the day, and had soemthign in stock.
Lasted about a year(30K klms, maybe less) and gave me a death wobble.
Annoyance was that it was discounted as the source due to it being close to new, and felt tight(slack free) .. but on a hunch and nothing else to point the spanners at .. just bought a std(Armstrong) type .. for, $40 worth the small price guess .. and voila! .. no more wobbles.

[350RRC]

The springs on my POS were installed in 1990, well before I bought it......... Pedders heavy duty high lift. (all of 2")

They've done 700 thou without sagging. Had Pedders shocks on it too from memory which had to be replaced at 300 thou, about the time I got it. Had been round Oz apparently.

Has had a set of Monroes on it for 200 thou approx now (I didn't buy them) with absolutely no probs at all except bigger pin size, which turned out to be a bonus.......... use Toy cups and bushes (out of a parts bin)!

DL