polyair vs firestone for 105 series cruiser

I agree with that I tried Polyairs and wasnt very happy so bought a set so King Progressive springs. Were much better and gave the normal ride when running empty and still kept it level when loaded Only cost $180 which was cheaper than the airbags.

I agree Colin, airbags are a false cheap option for tightwads to cheap and uneducated to buy the springs and shocks for the job.

Plenty of google evidence of their use and failures.

I thought the 105 ser was coil sprung so transferring weight and cracking or bending the chassis shouldn't be an issue so fitting air bags should be fine if used correctly. But it may create a problem removing the bump stops.

I have a different opinion on the plastic/synthetic or what ever they are bags. I've had 2 sets a long time ago on an early Range Rover. The first set lasted for a few years and served well but eventually one developed a leak around the top fitting so they came off the car. During that time they did actually save me once when a spring broke and I rode along with the collapsed spring for about 200km without knowing it. That side was just slightly lower. The 2nd set though gave me doubts about durability. They were bought a few years later and only lasted just over a year. The failure was complete in that both bags went brittle and literally crumbled to pieces around the same time. Complaints to the maker failed and they claimed that there was no problem with the bags even though they declined to have some pieces sent to them as well as being out of the warranty period. They also put the blame back on me that I must not have kept at least the minimum pressure in them. Was never any problem for me with the earlier set.
The way they crumbled was similar to what I've seen with some synthetic soled shoes where with age they can crumble to pieces and got me wondering if these air bags have a shelf life and should be sold ASAP after production and be fitted and in regular use. Anyway, with the ute's that I have these days I would never consider them on them and prefer to get the springs right. I'm not saying that these type of air bags are rubbish, and from the responses here there's people that have had a long life out of the, it's just that my experience doesn't give me faith in them any more.
My experiences in swapping coils springs on the rear did teach me how long it can take to do it and maybe a possibility is to have 2 sets of rear coils and change them over when required for a trip. With a bit a practice it became well within a 2 hour job. There's enough people who swap to different rims & tyres for remote trips and changing coils wasn't real difficult. When the coil broke on my RR I did the change over in a fuel stop car park by myself as I had added the spring compressor's as a last minute thought before the trip. Even though they weren't totally adequate the locally sourced springs did get me home.

That's another good fix as opposed to air bags.
Just one more point ,when I looked at some cars with air bags the owner thought they were great and worked well only to find that the chassis was bending without them actually realising , caught the problem early however still needed repairing .
Iv'e thrown away 3 sets from cars that iv'e repaired , it makes me angry that they actually sell this garbage, they ruin cars .

Air bags in coil sprung vehicles can cause absolutely no damage at all if there isn't any or at least some minimal load however if the common sense factor comes into it and you have the vehicle packed to the brim and whack a trailer or a caravan on the back as well , who goes and weighs their vehicle to see if all is safe ? not many .
Common sense would have you think that the car is strong enough to carry the weight and that I have even more common sense to put air bags on just to make sure everything is right .
That's the story I heard from the person that had the bent chassis on the Prado .
The distance on an after market rated coil sprung vehicle from the chassis to the bump stop is huge , so you can load up the car , caravan on the back go over rough roads , humps bumps etc and the chance of bottoming out are remote , then put an air bag up the centre of the spring , pump it up to level out the vehicle and what you have is a hinging point for a bend , they become one big bump stop .
When it comes to suspension , people think they are doing the right thing and are conned into such things as airbags as a supplement suspension aid , that's common sense for someone who doesn't know the ramifications .
I have dual wheel carriers on my 78 series Troop Carrier however I do have an after market spring that can carry the load , my car doesn't bottom out because my springs dampen the the weight over bumps and the shock absorbers absorb the shock obviously , there fore the weight is distributed evenly from one end of the leaves to the other .
Same goes for coils , let the spring do it's job , manufacturers never put air bags on cars with springs .
I think that the person who started this post does have common sense for asking in the first place and has written that he is not going to fit them , a really sensible person .

Colin