BT50 Suspension

matty_turbo · Newbie

BT50 Suspension

Dougwe · Chief one feather

Welcome to the gang Matt, enjoy here and out in the playground.

Not a BT50 but I have a 2014 Colorado and just recently added an extra leaf each side to rear springs, it raised the back up about 2", strengthened things up a bit and tows great now. I tow 2,750kg with 250kg on the ball. Extremely happy and well worth the $$$.

I got the job done at Pedders.

D and D · Guru

We have been towing for about a year and a half using a 2013 BT50 to pull our van that weighs about 3.3 tonne with no modification to the suspension and we haven't noticed any deterioration in the ride over that time. We do use a HR WDH and that makes a difference and we've also had an AL-KO ESC installed. The original tyres need replacing after 40 000 K which is a little disappointing but I don't know if the rear suspension had anything to do with that.

Regards

Dave

Cruising Cruze · Guru

Hi Matt

Also welcome to the site

1300 kg in the back is a hell of a lot mate

Be carefull that you don't end up with something like this

Cheers John

Radar · Guru

Hi Matty_turbo.

I like you I had tried to set my ute up for various types of use a. Travel in comfort, b. Tow our caravan with ease and safety, c. Off road use a bit.

In the end our Navara crew cab with standard springs in the rear I went with air bags, with our ute loaded with surplus gear, all the extras and 200 kgs on the tow bar would be close to it's maximum weight.

A. It is comfortable when empty or with the caravan, 10 lbs.of air or could go a bit further with added pressure but found this was enough pressure to keep the ute level or close to where it was when empty with out over doing it.

B. Tows the caravan lots better then without and looks the part as it now sits level.

C. Navara is a four wheel drive and where I mostly want to go would be over well warn tracks and would handle that with easy or care.

The cost of the air bags was very acceptable at $472 plus fitting. Not from a well advertised source but do believe the quality is there. Gold Coast firm.

Only other thing I am going to do before I go away again in a few months is up grade our shockers to a better after market as I believe the standard are not good enough and lets the whole ride down and ride would get worse on continual long kilometres of dirt roads.

I really don't like the scare tactics of people putting up those odd photos, I do wish they would loose them.

I hope some of my thoughts are of help but remember the kiss principle when setting yourself up for long distant travel as your home garage is never near when you need to carry out repairs on modifications. Ralph.

-- Edited by Radar on Tuesday 19th of May 2015 02:52:19 PM

JackoFJR · Senior Member

Bent , broken chassis is not just scare tactics , in my travels I have seen a few , mostly Dual Cabs ,
if your std suspension is not up to the job for the load you carry , its best to get it sorted by a Spring Works and avoid air bags .

matty_turbo · Newbie

Thanks everyone. Seems like EFS do a nice comfort package with a 2 inch lift. Cheers

dogbox · Guru

Radar wrote:
Hi Matty_turbo.
I like you I had tried to set my ute up for various types of use a. Travel in comfort, b. Tow our caravan with ease and safety, c. Off road use a bit.
In the end our Navara crew cab with standard springs in the rear I went with air bags, with our ute loaded with surplus gear, all the extras and 200 kgs on the tow bar would be close to it's maximum weight.
A. It is comfortable when empty or with the caravan, 10 lbs.of air or could go a bit further with added pressure but found this was enough pressure to keep the ute level or close to where it was when empty with out over doing it.
B. Tows the caravan lots better then without and looks the part as it now sits level.
C. Navara is a four wheel drive and where I mostly want to go would be over well warn tracks and would handle that with easy or care.
The cost of the air bags was very acceptable at $472 plus fitting. Not from a well advertised source but do believe the quality is there. Gold Coast firm.
Only other thing I am going to do before I go away again in a few months is up grade our shockers to a better after market as I believe the standard are not good enough and lets the whole ride down and ride would get worse on continual long kilometres of dirt roads.
I really don't like the scare tactics of people putting up those odd photos, I do wish they would loose them.
I hope some of my thoughts are of help but remember the kiss principle when setting yourself up for long distant travel as your home garage is never near when you need to carry out repairs on modifications. Ralph.

-- Edited by Radar on Tuesday 19th of May 2015 02:52:19 PM

those scare tactics of the odd photos are pictures of utes with broken back most are caused by the use of over inflated airbags that change the load point on the chasis

Radar · Guru

Hi Jacko

Did you or would you take the time to under stand what really goes on in these situation when vehicles break their chassis.

The Poster is looking for advice base on experience. Like you I have seen lots but I try to reason out what has happened.

There is fleets of ambulance running around with air bags helping to stabilize them, air bags are use in different forms of motor racing for spring control.

Main difference using springs you only get one choice, loaded or empty, you will not get it both ways. It is a compromise only.

There is thousand of trucks using air bag suspensions. I have seen a few crew cabs utes chassis broken near the front spring hanger, 2 of were towing way too heavy work trailers over country dirt roads thought the central west of NSW. One guy had 2 utes broke the chassis in both, both times the dealer told him it was the steel framed tray ie. No flex, guess what still drives the some make of ute 20 years on and no air bags.

Using air bags is not the problem, it appears the using and miss use of air bags is the problem by the owners.

To make a vehicle do what this Poster wants is going to be a total compromise, to me it was very rewarding to maintain a good ride when empty and then capable too handle the load. Not one spring would do that.

So far I have about 7000 ks up and smiling. Ralph.

JackoFJR · Senior Member

I understand why a chassis breaks and no not all have air bags and not all Dual Cabs .
It's usually overloading the back of the ute / tray and then hooking up a trailer/van that has a heavy ball weight , hit a bump you didn't see soon enough and crunch it's all over .

Air Bags will compound the problem , the chassis will be taking the load where it was never ment to be .

Mates of mine have used Air Bags on leaf sprung vehicles without problems because they knew what they were doing , but even they have now bought new 4x4's and have decided not to use Air Bags again .

We have access to a weigh bridge any time at no cost and run our vehicles over it before all trips , just because we can
The mates and I know what our vehicles weigh and believe me there is hundreds out there that must have no idea

You only have to Google Air Bags or if you happen to be in Birdsville go have a talk to Barnsey at Birdsville Auto and ask him what he thinks of Air Bags on leaf sprung vehicles .

I would suggest to the OP , Matt , load up your BT50 , hook up the Van and let someone at a Spring Works have a look and take their advice

Properly sorted springs and shocks front and rear is by far the best way to go , yes it will cost more , somewhere in the range of $2200 to $2400 .

Gundog · Guru

JackoFJR wrote:

You only have to Google Air Bags or if you happen to be in Birdsville go have a talk to Barnsey at Birdsville Auto and ask him what he thinks of Air Bags on leaf sprung vehicles .

Jacko unfortunately like many you believe the rubbish published about air bags, it's not the fault of the airbags.

1. The design of crew cabs is the single biggest issue.

2 It's the owners fault they put too much weight on the rear of the vehicle, because there is nowhere else for it to go.

3 Pressure too high in the bags.

4 In extreme off roading all the weight of the trailer/van can be thrown onto the ball/rear of ute in certain circumstances.

It's pretty easy to draw a long bow and blame the airbags, likewise for Mr Birdsville Auto, has any body bothered to do a proper case study of the circumstances that caused the chassis failure A. Vehicle brand. B. Load Distribution. C Air Bag Pressure. D. Terrain E. Driver Experience. F. exact location of Chassis Failure, are just a few of the controls needed to carryout a factual study. And I will bet London to a Brick, the driver would accept no blame other than its the air bags fault because that's the easy way out.

If Air Bags were solely to blame there would have been massive litigation of air bag manufactures by insurance companies, I haven't heard of any if there has been and they won air bags would be withdrawn form the market for fitment to Crew Cab Utes.

So unfortunately common sense does not prevail in this subject, its easy to follow the sheep and hop on the bandwagon and blame something that is not substantiated by proven facts, yes sure there has been failures but again circumstances causing the failure are devoid the full story.

PeterD · Guru

matty_turbo wrote:
To tow it we have purchased a 2013 manual Mazda BT50 GT with a steel bar, canopy etc.

Snip

Obviously I dont want to lose the 1300kgs payload in the rear. But I just want to raise it slightly and toughen the shocks/leafs slightly.

Matt, you have lost a lot of that 1300 kg already. The canopy will be around 100 kg and the steel bar around 70 kg. I'm not sure of the tow bar weight so I would say you have lost over 200 kg already. Don't forget that the driver, passengers and fuel also come out of the 1300 kg payload, that payload allowance is not totally for the "payload in the rear."

We then have to consider the ball weight of the van. If you are not using WDH (weight distribution hitch - often called load levellers or incorrectly sway bars) you need to consider how the load is distributed to the axles. When you couple the van you will note the front end rises a bit. That is because lever action reduces the weight on the front wheels. That weight is now carried by the rear wheels. It is not uncommon for the weight on the rear wheels to increase by the ball weight and 50% of the ball weight (the exact amount will be the percentage the ball overhang is compared to your wheelbase.) You say that the vans ball weight is 240 kg, I assume that is the unloaded ball weight, it is likely to increase significantly when you load the van. That 150% of 240 kg (or what you work it out to be) has to be considered as part of the load.

The other thing about stiffening the rear suspension, the designers of your vehicle have built in a controlled amount of under-steer. This is to give your vehicle good stability. Stiffening your rear suspension will reduce this under-steer and probably introduce a bit of over-steer. Do you really want this characteristic with a van on the back? Some light reading for you, go to Articles Index, scroll down to the heading Vehicle Suspension and read the articles under it.

JackoFJR · Senior Member

Gundog , I think that's exactly what I said , it's a combination of all those things . The design of Dual Cabs yes thats right , don't put Air Bags on em .
The Hilux I have just sold went over the weigh bridge @ 3300kg , way over its 2780 GVM , I had well sorted suspension and no Air Bags
it handled the load no problems . We do a lot of 4wding in the Vic Highcountry, Simpson a few times , Cape a couple of times , Gibb plus plenty of Out Back Dirtroads .

Radar · Guru

JackoFJR wrote:
Gundog , I think that's exactly what I said , it's a combination of all those things . The design of Dual Cabs yes thats right , don't put Air Bags on em .
The Hilux I have just sold went over the weigh bridge @ 3300kg , way over its 2780 GVM , I had well sorted suspension and no Air Bags
it handled the load no problems . We do a lot of 4wding in the Vic Highcountry, Simpson a few times , Cape a couple of times , Gibb plus plenty of Out Back Dirtroads .

I would say I rest my case. Ralph.

JackoFJR · Senior Member

I would say I rest my case. Ralph.

yeah me 2 .

Aus-Kiwi · Guru

Damage is 90% the nut behind the wheel..
Plus I think Patrol type full body is far stronger..

KJB · Guru

If you increase the "spring rate " (via the addition of airbags ) you must also adjust the shock absorber rate if you expect to end up with ultimate handling package. Remember - a spring without shock absorber is how a "pogo stick " is made.

KB

Aus-Kiwi · Guru

Air bags don't bounce like coil springs ..