Suspension and van sways side to side

Hi,

I have a 1996 Supercustom 3.0L Turbo Diesel. Love it. The problem i have though is that the suspension seems rather soft and the van sways as it goes around corners. Took it to a couple of suspension places here in Gladstone (QLD) but i didnt feel they really knew what they were looking at (not familliar with these vehicles). Ended up paying $500 to get 2 airbags installed in the rear springs. Does anyone have similar swaying issues with their van? If so, do you know how to fix it? Does anyone know of good mechanics/suspension places that are familiar with these super customs around the Rockhampton-Gladstone-Bundaberg-Hervey Bay-Sunshine Coast areas?

Thanks

Darren

Do you have TEMS fitted, you will have a switch if you have?

Check trailing arm bushes and anti roll bar bushes.....

New Heavy Duty Gas Shocks should help the problem.

What tyres are you using?

This sort of instability can be caused by marginal or mismatched tyres... You often find the DPO has scrimped as good ones are a lot more expensive.
Unless they are sound then money spent on suspension will be wasted.
Cheers,
W.

Hi Darren...
Any news on this? have you had a chance to check what spec your tyres are?

This is a bit of a bugbear of mine (see the thread on tyre selection on this board!) as I've often come across contributors having handling issues with campers because some monkey at a tyre shop didn't realise that a 2-tonne van needs chunkier rubber than a lightweight soft-roader... Used to be a recurring thread on the VW bus groups, as the right tyres were hard to find in the US, so people would end up with whatever the tyre shop had in stock andthen down-th-line they'd be wondering why the handling seemed iffy...

Might not be your problem, though...!

Cheers,
W.

after having vrs space cruisers and townace (s ) and of course the superdooper custom then i will say there a bouncy mess at the best of times , top gear said its one of the worst handling cars ever ( space cruiser ) and they maybe had a point ? me i dont care , so its a little soft , thats normal and doesnt detract from the rest of the package IMO , ive grown used to having the odd moment of 3 or even 2 wheels on the deck

Hi,
Have been thinking about this during and after a long trip during the summer and I think SCs are more capable than some people are assuming.
The suspension's pretty basic- the front axle is right under the seats and the rear is a solid axle on leaf-springs, so the handling proper is never going to be sports-car brilliant. However, having said that, the spring-rates, shocks and overall setup are fundamentally OK, so if you ensure that everything's tight, the shocks arn't worn out and fit tyres that are up to the job of supporting a tall, two-tonne vehicle, you'll be rewarded with stability on the highway. It'll be a bit rough on uneven surfaces due to the lack of independent suspension but you shouldn't have to live with lots of body roll when cornering or terrible instability in crosswinds.
I hired a Mazda Bongo a few years back and it was much worse than my HiAce- the steering was overassisted, the wheelbase short for the height and the springing too light to control it so the ride was choppy. Similarly, some "proper" off-road vehicles I've driven have felt top-heavy because of the high clearance and soft springing you need on uneven ground.

To me the HiAce SC doesn't feel like a bouncy mess... it's just a bit prone to banging and thumping on potholes & speed bumps. On a reasonable surface it's a pretty decent drive- we did a couple of 300-400 mile runs with stops only for fuel & comfort breaks without feeling particularly stressed, despite some pretty poor weather.

Cheers,
W.

My Hiace had rear coil springs.

Curently back in a Townace I feel that as has been said fitting correct tyres can cure lots of handling problems.
It was just a Lite-Ace van converted for crew bus duties that blossomed into a MPV. Similar with the Hiace. The basic chassis was designed for normal road use. The introduction of 4WD to the range was to meet customer requirements in the more remote parts of Japan.

Do what you can to sort out annoying problems then enjoy it for what it is.

We did a 600 KM round trip last Friday, we also parked up with no ill effects. Must be average Japanese size?

I am surprised that no-one has mentioned tyre pressures...........
If your not running at least 55 / 45 (front / rear) PSI in them then your tyres are too soft and you will get the 'wallowing' feeling you've been experiencing.

Also, check your shock absorbers, check the bushes in the upper front control arms and the rear control arms.
Worn top ball joints in the front suspension can also give this feeling to the cars handling too.


I hope this helps,

Hi,
MaXiLeeCH makes a good point- as per the earlier post on tyre pressures in General:

https://hiace-super-custom.forumotion.com/t2288-tyre-pressures-finding-a-pump

...the SC should have higher pressures than a standard car (as you might expect, given that it's basically a van). Check the maximum pressure on your current tyres, though, if someone's scrimped on them they may not be rated for this sort of pressure and you'll need to replace them.

Oh, and the higher pressure is in the rear, not the front!

Cheers,
W.

WGWarburton wrote:

Hi,
MaXiLeeCH makes a good point- as per the earlier post on tyre pressures in General:

https://hiace-super-custom.forumotion.com/t2288-tyre-pressures-finding-a-pump

...the SC should have higher pressures than a standard car (as you might expect, given that it's basically a van). Check the maximum pressure on your current tyres, though, if someone's scrimped on them they may not be rated for this sort of pressure and you'll need to replace them.

Oh, and the higher pressure is in the rear, not the front!

Cheers,
W.

Actually, read your manual, higher pressures go in the front of all of the hiaces and their clones.
Particularly so with the diesel models, because of the weight of the engine.
Stock pressure is somewhat higher than 55 psi from memory too for the front, somewhere closer to 70 PSI is better.

Certainly read your manual and/or placards. My LH119 definitely placards the higher pressure to the rear - 50psi front, 65psi rear. And yes, it is a diesel.

I think from memory my placards say 35 psi, front & rear and it's a diesel...

Maximum pressures for tyres is only 44 psi. They are only cheapie Chinese Hifly's which were brand new when I got the vehicle. I'm going to replace them with something decent once they are in need of replacing. They are rated for the van's weight.

Hmmm, it seems as though SC's have their tyre pressures bass ackwards, as there is far more weight on the front than the rear.
The handbook for my Hiace commuter says 75 psi front, 65 psi rear for a full load............ unladen pressures are 55 / 45...........go figure.
(My van does not have and never has had a tyre placard.)

I run my van (which is now setup as a camper with a GVM of 2.1tonne) at 50PSI all round which is a little low on the front but it smooths out the ride something awesome!

I think it is the difference between car and commercial tyres. If the tyre is marked as max of 50 PSI or higher and/or is 8 ply it is likely to be intended for commercial use i.e. as a builders van. Maybe as the commuter and camper conversions are of a heavier build then these tyres are fitted? Normal Car tyres will rarely have a max PSI over 50.

Clive wrote:

I think it is the difference between car and commercial tyres. If the tyre is marked as max of 50 PSI or higher and/or is 8 ply it is likely to be intended for commercial use i.e. as a builders van. Maybe as the commuter and camper conversions are of a heavier build then these tyres are fitted? Normal Car tyres will rarely have a max PSI over 50.

Yes, I think this is right. Tyres are classified into different groups according to their intended use- Passenger Car, Offroad, Commercial or Light Truck etc.

Unfortunately, the classifications have varied with region and with time, as cars and tyre construction have developed.

This means that there are various national, regional and international schemes and standards, with different names and slightly different groupings, depending on their target market. In the US, for example, there are lots of "Light Trucks"- ie pickups with a payload of a tonne or two. In Europe, it's more common to have a van, though obviously pickups are used on farms etc. Add to this the popularity of luxury 4x4s for road use and the use of van-sized people carriers or minivans for families and the tyre market can be seen to be really complex.
It doesn't help that they all look pretty much the same, too!

The cheap end of the market is for passenger tyres, made in quantity and intended for light vehicles. The lighter versions of the Hiace can use these, as long as the tyre is rated appropriately (weight rating and adequate maximum pressure). You can get Reinforced (or Extra Load) tyres, too. these are designed for heavier loads (Duh!) and can run at higher pressures. Again, suitable for lighter Hiaces. They may not be available in the "correct" size, though.
Next step up the rung are Light Truck or Commercial vehicle tyres. Some designed for 4x4s, either luxury off-roader types or pick-ups, others for vans. Commercial rated tyres come in different Load Ranges (typically C or D) and "ply ratings"... I can't even tell which of these terms is current- certainly "ply ratings" refer back to crossply tyres and have no direct connection to anything much these days! A "six ply rated" (or 6PR) tyre is usually (always?) Load Range-C, though and 8PRs Load Range-D. It could be that the Ply ratings pre-date a standardisation attempt to adopt Load Ranges?

For bigger Hiaces," Load Range C" or "Load Range D" tyres are needed and will provide plenty of sidewall support and stability. Some to the extent that they will give a harsh ride when the vehicle isn't loaded. Typically these wil be rated up to 65psi or more, so will comfortable handle the 60 or so that bigger hiaces need. Often these have a "C" suffix to indicate that they are Commercial Vehicle tyres (or maybe that they are Load Range C? It's hard to tell but LR-D ones seem to have the suffix, too!).
In the UK it can be hard to find Van tyres in the "4x4" size specified on many Hiaces (195R15C), it isn't easy to find 4x4 tyres with the right weight-rating either. Both do exist, though. If you have a bigger Hiace (LWB, hitop, lots of interior fittings or often loaded up, 4WD etc) then you probably need proper commercial vehicle tyres.

It's a complicated business, and with decent tyres costing £400 or so a set and being a key safety issue, it's not something you want to get wrong!

Cheers,
W.

Here in Australia, Hiaces are classed as commercial vehicles and they are required to use 8 ply rated tyres.
Lots of people are fitting mag wheels and passenger tyres and are getting pinged by the authorities for illegal tyres.

8 ply refers to amount of rayon bands giving a stiffer side wall. Nothing to do with cross ply tyre construction.

Clive wrote:

8 ply refers to amount of rayon bands giving a stiffer side wall. Nothing to do with cross ply tyre construction.

You may well be right but, if so, there's a lot of misinformation around on the topic!

Here's one from a UK tyre seller:

http://tyresavings.com/articles/safe-driving/checking-your-tyres/ply-rating-explained

It seem to be a common explanation for the term... I don't know the real story.

I do know that 6-ply or 8-ply rated tyres give a more stable van, albeit possibly at the risk of a harsher ride...

Cheers,
W.