More suspension help

[Swede50]

Hi,
I have a NT Diesel ARB bar with winch,dual batteries and Bushkins IC and sump guard.
Rear was basically empty when measured, less then half tank of fuel.
The suspension was on the car when I bought it has 270K on the clock Bilstein shocks
The labels were still on the springs
Front Springs are Lovells CFR-90HD
Ride height
L: 510mm
R: 515mm
Rear Springs are Lovells CRR-91HD
Ride height
L: 540mm
R: 545mm
I am not unhappy with how the car drives.
On last outback trip all was good on the high speed gravel etc.
However, the ride height seems low from some posts on here
I was wondering if the springs might have sagged.
Any advise would be great
Thanks

[old Jack]

factory ride heights are 503mm front and 533mm rear so you have a small lift. Depending on the weights you carry my guess is when you are fully loaded the current suspension drops from 510/515mm front and 540/545mm rear down to around the 500mm front and 500/510mm rear.
Is this correct?
This is higher much than factory suspension under the same loads.
With another suspension setup you can get around the 530mm front and 540mm rear when at GVM but this means 545mm front and 575mm rear when unladen. To get this results means knowing your exact axle loads laden and unladen and then selecting the coils for the weights and ride heights. This is particularly difficult because of the independent suspension front and rear, it is also and expensive exericise and although the ride height should be close to the targets, the ride comfort and handling may not meet your expectations.

What do you like about your current setup?
What do you not like about your current setup?

OJ.

[Swede50]

Hi OJ,
Thanks for your reply.
I have not measured loaded.
There is however little change to front
The rear goes to just above level,rear,, only from some photos, not measured.
We had extra spare wheel and a back up jerry can inside + 30L water and third battery
Fairly light camping gear and basic recovery kit.
Positive
The vehicle handles well when loaded
I probably drive a bit faster then most on the gravel.
I also prefer a firmer ride and more controlled suspension movement,,,
Got used to it in a rally car year ago
Negative
Extra clearance is always nice to have. It feels a bit low at the front.

I travel as light as I can,,, as we all do.
I guess that I will have to go to the weigh bridge at some point.
Also will try to work out my camping gear weight.

The car in not a daily driver so empty "comfort" is not on the shopping list

Cheers, Johan

[old Jack]

Hi Johan,

Do you know how many kms on the Bilstein's?
If over 100,000 to 120,000kms they will be getting tired.
Can you notice any shocker or strut fade?
Do the struts and shocker still control repetitive sequential deep compressions or do they start to lose rebound control?

OJ.

[Swede50]

Hi
The fronts are still OK... rebound still under control
The rears are new ... one leaking after last trip, still working
I have a contact and got replacement at super low price
I quite like them ... great control for what I have done so far.
No shocks are perfect for all conditions
They care a bit too stiff for the really bad corrugations but over all I am happy

Sent from my SM-G955F using Tapatalk

[pt3021]

i have just checked my ride heights i have the same set up same part no coils and bilstein shocks .
front is 540mm
rear is 570mm
these have done approximately 200,000klms mostly towing 3t caravan.i would suggest checking the rubber spring seats top and bottom with that sort of mileage they would be worn .these are expensive genuine but are available from http://www.polytuff.com.au. the other issue you may have on the front is the bilstein struts have two different spring seat heights that you can change by moving the circlip on the shock body.yours may be on the low setting i used this setting till i added a winch and then changed to the upper seat..
cheers steve

[Swede50]

Hi PT3021

Thanks for your information.
I have had a look at the struts and can't see any way to tell which groove the clip is in.
I wonder if anyone could post a measurement from the spring base down to give me an idea.
BIG job to pull apart only to find it is already in the top groove.

Cheers, Johan

[Swede50]

Further to this old thread,

I have been thinking about OJ's comments re the rebound on the front struts.
Flat road comfort is OK, small corrugations is OK .
Larger undulations leave a question mark.
Large corrugations,,, not good at all, but what is,
My only vehicle to compare is a Patrol towing a camper trailer with EFS suspension..... a long time ago now.
The Patrol was much more comfortable on the corrugations.
So, if I was to replace it all is there any reason that Koni is not high on the shopping list.
Most who have it seem happy. I will work out the correct springs for my weights after this lock down is over and I can get the weights.
Opinions on Koni...
Cheers,

[erad]

I cannot say for sure these days, but many years ago I had Konis on various cars, and they are still me preference. On the cars, they were one way ie they didn't damp much on the spring compression, but they worked hard on the rebound. This gave a reasonably soft ride when you hit a speed hump or similar. Not sure if the other brands have the same damping characteristics, but it used to work well fro me with my cars. And the Konis were repairable when finally the odd one started to leak.

[nj swb]

Further to this old thread,

I have been thinking about OJ's comments re the rebound on the front struts.
Flat road comfort is OK, small corrugations is OK .
Larger undulations leave a question mark.
Large corrugations,,, not good at all, but what is,
My only vehicle to compare is a Patrol towing a camper trailer with EFS suspension..... a long time ago now.
The Patrol was much more comfortable on the corrugations.
So, if I was to replace it all is there any reason that Koni is not high on the shopping list.
Most who have it seem happy. I will work out the correct springs for my weights after this lock down is over and I can get the weights.
Opinions on Koni...
Cheers,

A long time ago, on a Pajero from a generation not current, Koni shock absorbers that were supplied to fit Pajeros were too short for the front - the shock would hit the end of its travel before the droop stops did their thing, and the shocks would fail. And Koni would deny a warranty claim.

Current generation Pajeros don't have droop stops, and rely on the strut hitting the end of its travel - so presumably they are now designed to cope. But I would be interested to know how they go for travel - front and rear versions.

[Swede50]

Thanks Erad and NJ,
I was under the front the other day and the Billies do look very old.
Did a bit of speed hump testing in the deserted car park on the weekend... no one was looking I think.
The front struts are not up to the job after being critical about their performance
I am looking at a Aux fuel ( LRA ???) tank for a trip next year... hopefully with the current restrictions lifted.
To that end I ordered a set of KCRR-35 EHD springs and Polytuff top and bottom insulators.
Only grabbed the springs as they were on sale.... lockdown online shopping blitz ... LoL
Front springs after front weights worked out.

There are not many recommendations for Shocks on here for heavy loads
OJ has mentioned that he likes the Dobinsons he is using but little re the Koni's
If it is only the price of the Koni's I will weigh up the cost vs. benefit and decide.
Any thoughts welcome

Cheers,
Johan

[old Jack]

Hi Johan,

Koni have a solid long term reputation as a good expedition shocker and strut.
The Dobinson MT/IMS that I use are good but and better for my requirements than the Bilstein B6 however I only have just over 40,000km on the Dobinson so in my mind it is too early to make the call in regard to longevity.

Koni are a twin tube design whereas the Dobinson are monotube design, in theory the monotubes should before better and for longer over extended corrugations because they have more oil capacity, greater surface area to dissipate the heat.

OJ.

[Swede50]

Hi OJ, and thanks for your reply.

What you say re the heat dissipation makes sense
What I would really like are remote res shocks
After the problems other members have had with MRR's I will stay away from them.
Other options thin on the ground. at sensible pricing anyway.
After I get the front weights I will ask for your kind assistance with coil recommendations.
It would be nice if Dobinsons had what I require as I could just order ready struts, I don't have the facility to assemble struts anymore.
However Pedders are next door at work so anything can be done.
For the price of the Dobinsons I might just give them a go and see.
They will have to be better then what I have now.

On another note, I replaced the rear Billies.
Mine came direct from Germany through a contact I have here,,,, added to their order.
They behave differently to the ones I replaced, one was leaking.
The compression is much more progressive, the "thumping" on the up stroke is no longer evident.
I have read on here from others that there can be different valving depending on importer ???
All the same part numbers

Cheers,
Johan

[Swede50]

Hi,

I thought that OJ was the worst/best suspension tragic I had seen
This on the Prado forum

In the front we are strongly limited by the IFS motion ratio in valving terms, so at the strut position it will be quite common to see struts with 2500N:1500N up to 3600N:2200N. Some struts will use even higher rebound Forces up to 5000N. Coil rates can typically vary from 600-800lb/in. In handling terms, it is better to have the front softer than the rear, something which is in any case forced upon us by the scaling nature of the IFS motion ratio. Keeping front:rear coil rates around the 700:300 ratio ensures the rear suspension frequency will be higher by around 10%, thereby minimising wheelbase length induced pitch for long spacing corrugations, while also keeping the front ride rate around 25% softer than the rear. Running a low front strut compression around 1500N leaves the IFS open to hard bump outs on taller corrugations, so keeping the compression around 2000N is preferable.

I have personally driven the 712/713 Bilstein setup on Ridepro coils with a heavy Prado over GVM on 50psi tires as a test case along the Great Central Road. The 712/713 are just copies of the OEM valving, and are considered as soft suspension on the Prado. This high tire pressure/soft suspension setup worked well, and handled nicely. I’ve also driven the complete opposite with soft tire pressure/hard suspension setup, with more like the valving discussed above, and the handling feels similar to me. In both cases I was driving at 90-100km/h.

Interesting reading
Now I understand why the Supercars went to a control shock
The cost involved in getting things right are huge.
I just want a "decent" set up.... sounding more and more like wishful thinking.

J.

[old Jack]

Hi,

I thought that OJ was the worst/best suspension tragic I had seen
This on the Prado forum

In the front we are strongly limited by the IFS motion ratio in valving terms, so at the strut position it will be quite common to see struts with 2500N:1500N up to 3600N:2200N. Some struts will use even higher rebound Forces up to 5000N. Coil rates can typically vary from 600-800lb/in. In handling terms, it is better to have the front softer than the rear, something which is in any case forced upon us by the scaling nature of the IFS motion ratio. Keeping front:rear coil rates around the 700:300 ratio ensures the rear suspension frequency will be higher by around 10%, thereby minimising wheelbase length induced pitch for long spacing corrugations, while also keeping the front ride rate around 25% softer than the rear. Running a low front strut compression around 1500N leaves the IFS open to hard bump outs on taller corrugations, so keeping the compression around 2000N is preferable.

I have personally driven the 712/713 Bilstein setup on Ridepro coils with a heavy Prado over GVM on 50psi tires as a test case along the Great Central Road. The 712/713 are just copies of the OEM valving, and are considered as soft suspension on the Prado. This high tire pressure/soft suspension setup worked well, and handled nicely. I’ve also driven the complete opposite with soft tire pressure/hard suspension setup, with more like the valving discussed above, and the handling feels similar to me. In both cases I was driving at 90-100km/h.

Interesting reading
Now I understand why the Supercars went to a control shock
The cost involved in getting things right are huge.
I just want a "decent" set up.... sounding more and more like wishful thinking.

J.

Hi J,

I am a suspension and tyre tragic, because these are most critical parts of on 4wd that is setup for remote touring. Get the combination wrong and it leads to all sorts of other problems, get it right and you increase the reliability of your vehicle and reduce operating costs.

For me it is strong 10ply rated LT tyres at low pressures, struts and shockers that are soft on compression and firm on rebound, lowest spring rate and longest springs possible for the loads carried at desired ride heights and progressive rate coils on the rear.

OJ.