Suspension Travel & Shockers

1
Mine don't bang and I would be a bit alarmed if they did. 
 
Normally, the up travel in a suspension system is limited by bump stops, not the shockers, and these bump stops compress before the spring goes solid.    Similarly, the downward limit usually has a mechanical restraint rather than a hydraulic restraint.  If it was otherwise, the shockers would be getting a lot of punishment that they weren't designed to take.
 
If the stop is inside the shock absorber, as has been suggested, it would never be metal to metal.  There would be a compressible component to take the load progressively before the limit is reached.  I have never had to look into this before but I will do some checking now that the matter has been raised.
 
If a vehicle has taller springs fitted, it will also need to have shockers that have the correct stroke and the correct end point of up and down stroke.
 
I have never hit a speed bump very hard so it could be that I have not reached the limit referred to here, but I know of no vehicle where the limit is metal to metal.
 
Greg,
 
I am running B F Goodrich All Terrains 215-75-15, which are 20 mm bigger diameter than the 8.5-27-14 BFG's.  Measuring from under the wheel arches to the ground, I have 800 mm front and 820 mm rear.  Take 20 mm off those figures and I would have 780 and 800.  St first sight, the Syncro looks like it has been jacked up but they are all the same.
 
And, on the subject of tyres, you must NEVER run dissimilar tyre sizes front and back.  Doing so stuffs the Viscous Coupling very quickly.
 
Les
 
 
----- Original Message -----
Sent: Wednesday, December 03, 2008 10:15 AM
Subject: Re: Re: [Syncro_T3_Australia] New Member

I never really noticed it until somebody showed it to me. I have to try to make it bump.
Phill

> Gary Cookson <gary@twentytwentyon e.net> wrote:
>
> Interesting, i have the same bang issue but it only happened when i
> fitted new rear shocks (Bilsteins). I'm pretty sure with the old
> shocks I didn't get the noise. I hadn't got any further with
> investigating though.
>
> Anyone else?
>
> [2 0 / 2 1 Design]
> 28 Gwynne St
> Richmond
> Vic 3121
> gary@twentytwentyon e.net
> www.twentytwentyone .net
> Tel 3 9429 1868
> Fax 3 9421 1110
> Mob 0417 352782
>
> On 03/12/2008, at 5:57 AM, plander@optusnet. com.au wrote:
>
> >
> > . It appears the
> > > vehicle is sitting a couple of inches higher than normal on 14" rims
> > > and the back end fairly bangs coming off speed bumps. Not sure
> > whether
> > > to change the springs back to original spec or the shockies. The
> > front
> > > is the same height but rides beautifully.
> > >
> >
> > The bang really is normal. It is just the suspension stop is inside
> > the shock absorber. If you have taller springs it will happen more
> > often.
> >
> >

2
> If the stop is inside the shock absorber, as has been suggested, it
> would never be metal to metal. There would be a compressible component
> to take the load progressively before the limit is reached. I have
> never had to look into this before but I will do some checking now that
> the matter has been raised.
>

There is not much room in the rear shocks for a decent compressible component. It's not a metal2metal sound. Just the sound of the shock reaching the limit.

To try it out, come off a steep speed hump at a 45 degree angle so that the wheel drops to full travel before hitting the ground.
3
Les, totally agree with your comments and i did have a look thinking i probably had some worn out bump stops or something that limited the downward travel of the suspension as i thought that surely this wouldn't be the job of the shockers but i have yet to find anything – but it sounds like Phill has checked this out from new.

My shocks (Bilsteins) were supplied and fitted by Volkspower and they had to order them in specifically for the Syncro as they are obviously longer than a standard T3. I can only assume they are the correct ones. My springs are standard and I have 215 75 15 BFGs. The 14s are the same as you'd expect.

My streets are paved with speed bumps and i never hit them hard either. Even the ones in the middle of the street that are made of hard rubber will cause the bang and the Syncro almost straddles them.

I did plan to take the shocks off and drive round the block to confirm it was the shocks but i don't think i'd better do that now or i'll be wrecking some cv joints or something else.

Gary


[2 0 / 2 1 Design]
28 Gwynne St
Richmond
Vic 3121
gary@twentytwentyone.net
www.twentytwentyone.net
Tel 3 9429 1868
Fax 3 9421 1110
Mob 0417 352782

On 03/12/2008, at 10:42 AM, Les Harris wrote:


Mine don't bang and I would be a bit alarmed if they did. 
 
Normally, the up travel in a suspension system is limited by bump stops, not the shockers, and these bump stops compress before the spring goes solid.    Similarly, the downward limit usually has a mechanical restraint rather than a hydraulic restraint.  If it was otherwise, the shockers would be getting a lot of punishment that they weren't designed to take.
 
If the stop is inside the shock absorber, as has been suggested, it would never be metal to metal.  There would be a compressible component to take the load progressively before the limit is reached.  I have never had to look into this before but I will do some checking now that the matter has been raised.
 
If a vehicle has taller springs fitted, it will also need to have shockers that have the correct stroke and the correct end point of up and down stroke.
 
I have never hit a speed bump very hard so it could be that I have not reached the limit referred to here, but I know of no vehicle where the limit is metal to metal.
 
Greg,
 
I am running B F Goodrich All Terrains 215-75-15, which are 20 mm bigger diameter than the 8.5-27-14 BFG's.  Measuring from under the wheel arches to the ground, I have 800 mm front and 820 mm rear.  Take 20 mm off those figures and I would have 780 and 800.  St first sight, the Syncro looks like it has been jacked up but they are all the same.
 
And, on the subject of tyres, you must NEVER run dissimilar tyre sizes front and back.  Doing so stuffs the Viscous Coupling very quickly.
 
Les
 
 
----- Original Message -----
Sent: Wednesday, December 03, 2008 10:15 AM
Subject: Re: Re: [Syncro_T3_Australi a] New Member

I never really noticed it until somebody showed it to me. I have to try to make it bump.
Phill

> Gary Cookson <gary@twentytwentyon e.net> wrote:
> 
> Interesting, i have the same bang issue but it only happened when i 
> fitted new rear shocks (Bilsteins). I'm pretty sure with the old 
> shocks I didn't get the noise. I hadn't got any further with 
> investigating though.
> 
> Anyone else?
> 
> [2 0 / 2 1 Design]
> 28 Gwynne St
> Richmond
> Vic 3121
> gary@twentytwentyon e.net
> www.twentytwentyone .net
> Tel 3 9429 1868
> Fax 3 9421 1110
> Mob 0417 352782
> 
> On 03/12/2008, at 5:57 AM, plander@optusnet. com.au wrote:
> 
> >
> > . It appears the
> > > vehicle is sitting a couple of inches higher than normal on 14" rims
> > > and the back end fairly bangs coming off speed bumps. Not sure 
> > whether
> > > to change the springs back to original spec or the shockies. The 
> > front
> > > is the same height but rides beautifully.
> > >
> >
> > The bang really is normal. It is just the suspension stop is inside 
> > the shock absorber. If you have taller springs it will happen more 
> > often.
> >
> >



4
Thanks Les

I am having our local retired VW legend Kevin Rowlands get under the
thing next week and take off a shockie and check the springs etc.

I have BFG All terrains on at the moment but they are bit noisy on
the black top.

I have 16" alloy rims and a set of 14" steel wheels.

I am not sure what tyres to put on for all round performance (99% of
driving will be on good roads) ie noise and reasonable off road
capability and I am not sure if I should use the 16s or 14s.

Does anyone have any ideas?







--- In Syncro_T3_Australia@yahoogroups.com, "Les Harris"
<leslieharris@...> wrote:
>
> Mine don't bang and I would be a bit alarmed if they did.
>
> Normally, the up travel in a suspension system is limited by bump
stops, not the shockers, and these bump stops compress before the
spring goes solid. Similarly, the downward limit usually has a
mechanical restraint rather than a hydraulic restraint. If it was
otherwise, the shockers would be getting a lot of punishment that
they weren't designed to take.
>
> If the stop is inside the shock absorber, as has been suggested, it
would never be metal to metal. There would be a compressible
component to take the load progressively before the limit is
reached. I have never had to look into this before but I will do
some checking now that the matter has been raised.
>
> If a vehicle has taller springs fitted, it will also need to have
shockers that have the correct stroke and the correct end point of up
and down stroke.
>
> I have never hit a speed bump very hard so it could be that I have
not reached the limit referred to here, but I know of no vehicle
where the limit is metal to metal.
>
> Greg,
>
> I am running B F Goodrich All Terrains 215-75-15, which are 20 mm
bigger diameter than the 8.5-27-14 BFG's. Measuring from under the
wheel arches to the ground, I have 800 mm front and 820 mm rear.
Take 20 mm off those figures and I would have 780 and 800. St first
sight, the Syncro looks like it has been jacked up but they are all
the same.
>
> And, on the subject of tyres, you must NEVER run dissimilar tyre
sizes front and back. Doing so stuffs the Viscous Coupling very
quickly.
>
> Les
>
>
> ----- Original Message -----
> From: plander@...
> To: Syncro_T3_Australia@yahoogroups.com
> Sent: Wednesday, December 03, 2008 10:15 AM
> Subject: Re: Re: [Syncro_T3_Australia] New Member
>
>
> I never really noticed it until somebody showed it to me. I have
to try to make it bump.
> Phill
>
> > Gary Cookson <gary@...> wrote:
> >
> > Interesting, i have the same bang issue but it only happened
when i
> > fitted new rear shocks (Bilsteins). I'm pretty sure with the
old
> > shocks I didn't get the noise. I hadn't got any further with
> > investigating though.
> >
> > Anyone else?
> >
> > [2 0 / 2 1 Design]
> > 28 Gwynne St
> > Richmond
> > Vic 3121
> > gary@...
> > www.twentytwentyone.net
> > Tel 3 9429 1868
> > Fax 3 9421 1110
> > Mob 0417 352782
> >
> > On 03/12/2008, at 5:57 AM, plander@... wrote:
> >
> > >
> > > . It appears the
> > > > vehicle is sitting a couple of inches higher than normal on
14" rims
> > > > and the back end fairly bangs coming off speed bumps. Not
sure
> > > whether
> > > > to change the springs back to original spec or the
shockies. The
> > > front
> > > > is the same height but rides beautifully.
> > > >
> > >
> > > The bang really is normal. It is just the suspension stop is
inside
> > > the shock absorber. If you have taller springs it will happen
more
> > > often.
> > >
> > >
>
5
Greg,
 
This is a bit of a multi-choice question. 
 
The widely used and widely praised B F Goodrich 8.5X27X14 All Terrain tyre no longer exists.  There will be some other 14" off-road tyres available but even they will be in shrinking supply as the fashion in motor vehicle design veers even further away from the functional to the ludicrous - like 22" X 40% tyres that pretend to be off-road capable.  People who go off-road for a living just wet themselves with laughter when they see these poser things.  (Common in Toorak and Double Bay, non-existent in the real bush!)
 
The noise of the BFG All Terrains is part of the territory.  There is no such thing as a silent off-road tyre.  The Syncro was not designed to be a silent town car,  It was designed to be - and it is - a hugely capable vehicle in very adverse terrain.
 
If silence is important to you, I suggest that you use a good quality highway tyre on the 14" wheels and reserve the 16" for a capable off-road tyre, noise notwithstanding. 
 
Les
 
 
----- Original Message -----
From: ngreg61
Sent: Saturday, December 06, 2008 6:05 PM
Subject: [Syncro_T3_Australia] Re: Suspension Travel & Shockers

Thanks Les

I am having our local retired VW legend Kevin Rowlands get under the
thing next week and take off a shockie and check the springs etc.

I have BFG All terrains on at the moment but they are bit noisy on
the black top.

I have 16" alloy rims and a set of 14" steel wheels.

I am not sure what tyres to put on for all round performance (99% of
driving will be on good roads) ie noise and reasonable off road
capability and I am not sure if I should use the 16s or 14s.

Does anyone have any ideas?

.