air bags vs big springs

[Dunmowin]

I have a 2003 Nissan Patrol 4.2 ltr turbo diesel. I am towing a Kedron ATV 21foot.

At present I have slightly heavier springs but not sure what they are as they were on the vehicle when I purchased it.I have Level riders on the van.. Also air bags on the patrol.And these are my problem as they keep going down. When I tow with them low of preasure I sure notice the differience,so I want to replace them.

My question is.....what is best. replace the air bags only....... get heavier springs and forget the air bags.....or replace both springs and air bags. We are on the road permenently and cover many miles some weeks. But there are times when we like an area we stay put, so I am thinking that the air bags are the way to go.What is the general oppinion of air bags ?

singed DUNMOWIN....curently in Boulia QLD after a week at the Birdsville Races.

[RickA]

Hi Dunmowin

We have both OME suspension and airbags (Airbag man).They have been on the tug for about 4yrs.now and work well together.

I blow the airbags up to 28 Lbs. when towing, and 10 when not.Still have a bit of weight in the back of the Cruiser ,fridge drawer system etc.Hope that helps.

Cheers

Rick

PS get your springs checked first,you may not have to replace them.

[Leon Brown]

Hi

I have OME heavy duty Springs (600kg)and Nitro shocks . These work really well. No air bag as these tend to reduce the travel in the springs when on uneven roads, tracks. My Van is 21 foot ATV. When van is attached the back end of the tug drop 2/3 mils. Ride Ok when van not on as I also have a Longrange fuel tank and tinny on the roof. Hope this is of benefit to you.

Leon

[the crow and i]

Hi Dunmowin

I purchased a Firestone Coil-Rite Kit Rear and a Firestone Level Command 11 system for our 100 Series from the USA.

The cost May 2010 was $419.05 USD delivered, this was cheaper than I could buy the airbags only in Aus.

They work fine no problems

/>http://www.truckspring.com/suspension-parts/helper-springs/air-spring-kits/firestone.aspx?make=Nissan&year=2003&model=Patrol

/>http://www.truckspring.com/products/Firestone-Level-Command-II-Air-Compressor-System---Single-Gauge__FIR2158.aspx

Cheers

Bryan

[Blinky Bill]

Hi Dunmowin,

I have a 1996 GQ Nissan Patrol 4.2 turbo diesel towing a Cross Country with ATV chassis ATM 3300kg. I have had the Patrol re-engineered to tow 3500kg from 2500kg, part of this process involved upgrading the suspension, I installed an OME setup with a 2" lift, in addition, although not required I also fitted airbags to the rear, fitting Airbag man air bags, I have in the past fitted Poly Air's to a previous GQ I owned, in comparison there is no real obvious difference apart from colour, however with the 2" lift a 2" spacer is required to be placed at the bottom of the bag to allow for the lift, in the case of airbag man they use a piece if plastic not unlike a milk bottle top, hollow in the middle where as Poly Air use a solid piece of circular rubber, I feel over time the plastic may compress requiring replacement, for this reason only I would in future favour the Poly Air product.

Air bags are a very basic product and it would be very unlikely you have pierced the bag, the leak can only be in either valve or the piping from the the valve to the bag, or where the pipe attatches to valve or the bag it may be worth ensuring the valves are tight or replacing them, replacements can be obtained from any tyre shop as they are a car tyre valve, try inflating them to say 30 pound and spray some soapy water around with a small spray atomiser and check for bubbles.

You have indicated heavier than standard springs are fitted, unless there is obvious sagging of these springs I would caution against replacing them, going too heavy can compromise the ride and comfort of the vehicle. I have a mate who owns a 4wd mechanical workshop here on the coast and it's a continuing problem I see in his workshop where people purchase springs elsewhere and bring then to him to fit against his advice, only to return and have them removed, bigger is not always better.

I have a long range fuel tank and Outback rear drawers, 40 litre Engel fridge, 3/4 steel roof rack with an extra spare wheel and tyre and two jerry cans of water, on a trip we did in May/June from the Gold Coast out to Longreach, Winton, Boulia, Birdsville, Innamincka Tibooburra, Broken Hill, Bourke, Lightning Ridge Warwick Beaudesert and back to the Gold Coast, I weighed the Patrol with a full tank of fuel and just me onboard and it weighed in at 2900kg, I didn't weigh the van, for the trip two extra people were added plus plus plus. I ran the airbags at 15 pounds which I was happy with, however in negotiating some of the dips in the road between Tibooburra and broken hill, I did bend the brake proportioning valve on the rear diff which was extended to compensate for the 2 inch lift it was a simple fix to straighten, however the dips were more like v's and deeper than anticipated, I would be reluctant to run much more than 20 pound in mine, but my springs are fairly stiff.

In my case I believe they add value and don't regret fitting them, you mention you notice the difference when they loose pressure, for this reason I would not consider removing for heavier springs.

I am also running 285 75 16 BF Goodrich A/T tyres, for interest this trip was 5800km with average fuel consuption 21 litre per 100 km, the Patrol handles the van with ease, the fitting of a front mounted intercooler in two weeks may well improve that consumption as well.

That's my thoughts, and my experience with my own Patrol, it may be worth looking for where the leak is, if its somthing as simple as loose valves, it would be a shame to spend money unnecessarily. I paid $300.00 for mine at the camping and fishing show in Brisbane April this year, plus fitting.

Good luck with your decision and safe travels.

Regards,

John

[Mrs Lynn Astill]

Hi Bill,

Not meaning to hijack the post, but I am interested in how and where you had your Patrol's towing capacity upgraded, if you don't mind.

Thanks

Chris

[Laurie and Helen]

John,

If you are talking about the blue airbags that fit inside the coils, I have recently upgraded my 100 series with a 2" lift with 360kg rear coil spring pack and specified 2" lift airbags, they cost no more than the standard height units.

cheers

[Blinky Bill]

Hi Laurie,

Thats intersting information, when I did my research at the begining of this year the 2" lift was stated when pricing for both Poly air and Airbag man, both advised it was required information as one was supplied with the 2" spacer included in the box the other didn't. You didn't mention which product you installed, if it was either of the ones mentioned I can only assume they are now manufacturing a longer bag and have dispensed with the spacer. I will make some enquiries and find out.

Chris, rather than post a lengthy reply to your question here and hijack this post I will email you my reply.

Regards,

John

[RickA]

Hi John (BB)

As mentioned earlier I have had Airbag man(blue) bags about 4yrs.,also have 2inch lift.But they just fitted longer bags(no spacers)so unless it is something new,you could have been given a bum steer.

Cheers

Rick

[Laurie and Helen]

Hi John,

I sourced all my gear through opposite lock in Toowoomba, tough dog shocks, springs and HD torsion bars with the airbag man (blue)to suit the 2" lift and than the diff drop kit and torsion bar reinforcing kit from Superior Engineering on the north coast.

On our recent trip, while on the black top I run the HR weight distribution hitch with just enough air in the airbags to keep them inflated (5psi), on the gravel I take the HR off and inflate the airbags up to 20 psi.

cheers