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c140cessna
Penny Collector Member
USA
419 Posts |
 Posted - 02/09/2009 : 19:39:33
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I haul lots of metal...at times over 2200 lbs....this is a lot of load for my Pontiac Montana and she squats a lot.
I went to Autozone and bought some Gabriel "Hi-Jackers" for $62 for the complete kit including the pressure feed line kit.
Easy install....simple remove old shocks and install the air shocks...dress in the pressure lines...drilled a hole in the back corner floor to make a clean place to charge with the air.
Maximum pressure is 200 psi. I put 1800 lbs in the back of the van this weekend.....did not remove the center seats...put most of the weight right over the rear wheels. Required the full 200 PSI but she was at normal-level ride height.
Put maximum 44 PSI in rear tires - this is needed at this heavy load and tires were within 500 lbs of their maximum load carry rating.
Drove very stable and not too harsh....just like no load.
You must let the air out of the shocks - down to 25 psi minimum without load.
This is the best money i've ever spent on a vehicle repair/upgrade.
It you haul with a small van like this....get some of these shocks. Monroe also make a similar product.
My little van is now a comfortable 1 ton truck! The shoch attachments look stout enought to take the load....and air leveling was an option from the factory...and this is true of most minivans.
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4 Posts |
Posted - 02/10/2009 : 02:59:04
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| Just be careful most shock mounts are not designed to hold weight.I saw a lot of 60's-70's cars running air shocks that riped the mounts for the shocks off or punched through the floors. You may need to reinforce the mounts on the vehicle. |
This is Legal Right ? |
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redneck
1000+ Penny Miser Member
1273 Posts |
Posted - 02/10/2009 : 05:23:12
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quote:
Originally posted by Bogie
Just be careful most shock mounts are not designed to hold weight.I saw a lot of 60's-70's cars running air shocks that riped the mounts for the shocks off or punched through the floors. You may need to reinforce the mounts on the vehicle.
I totally agree,I have seen that too,but it goes a lot farther than that.They use smaller wheel bearings and brakes in vehicles not designed to carry weight of that magnitude.Also, not designed for side thrust on other suspension components when cornering.Four bolt wheels that could shear the bolts off instead of six or eight bolt wheels designed for that weight. Transmission may not be designed for those weights,if anything,don't use overdrive when hauling those weights.
Remember, they use computer assist design when engineering a vehicle
to figure stresses and build them accordingly,not like the old days when things were overbuilt to compensate for stresses as computer modeling wasn't around.
Also, if your in a wreck and it's determined that it's your fault do to you overloading the design for the vehicle, there may be other implications .
I'm not trying to tell you your wrong,I would just hate to hear that you went around a corner and the wheel seared off.
There's reasons why 1/2 ton,3/4 ton and 1 ton trucks and vans exist.
Be careful...
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c140cessna
Penny Collector Member
USA
419 Posts |
Posted - 02/10/2009 : 07:13:01
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I hear you guys......I'm a mechanical engineer in the automotive industry......I was a structural engineer for the first 7 years of my career.
You might find this interesting about minivans and airshocks and loads....
Most cars are not appropriate for heavy loads from air shocks....but mini-vans are unique....I think everyone built these days has the option for load leveling if you get the factory trailer package. This is effectively what i now have....but it is a manual system. I was looking at the shock mounts on the axle beam as well as the mount at the body...very strong, big steel doublers.
Some other thoughts.....most minivans can come with 8 seats....8 x 170 lb passengers = 1360 lbs of passengers.....add in some luggage carry ability..... most minivans have roughly a 3/4 ton payload rating. Next time you look a minivan = think 1/2 ton pickup.
Typical worst case loading for most vehicles ....are designed for a truck shipping load case....where they chain the vehicles down on a truck with the suspension at full travel against the jounce (sometimes also called bounce) stops....typically a rubber absorber at the end of full suspension travel. When the vehicle is chained down this way...the tires are also compressed and so is the suspension...there is nothing but the very high spring rate jounce rubber to absorb most of the load/suspension input from the trnasport truck. With the tire pre-compressed it really makes for harsh loading....under normal conditions, the tire has roughly 10% - 20% the spring rate of the vehicle suspension....tire typically absorbe a lot of impact energy.
Also, it is not uncommon for maximum shock absorber loads to be as high as 15,000 to 20,000 lbs...but the loading duration is very short....a very high impulse load. Picture the shock....it has a thick internal disk with very small holes that oil passes through as it travels up and down....the more rapid you try to make it move = the more resistance it provides = that is why you get super high shock absorber input loads when you run through pot holes and you hear the "bang" in the suspension....the shock is nearly rigid for an instant....the tire is absorbing/slowing most of the vertical load input.
I have a lot of experience overloading vehicles without damaging them or creating a danger. The number one thing to remember is to not overload the tires....they all have a load rating on the sidewall and a maximum pressure to run to carry that load. You would typically have about 26 - 30 psi in them for a more comfortable ride under normal light passenger loads....but they have the ability to safely have about 40- 50 psi....a lot more load capacity than normal. Trucks may be as high as 60 - 70 psi.
So, mini-vans are a very unique little vehicle - they can really carry a big load and are designed to do so. That said, you have to be reasonable and pay attention to what you are doing....and knowledge and experience go a long way in helping. Also - you can't put big road input loads into the suspension on top of cargo over-loading.
A good indicator to follow -----when you look at the loaded suspenison....it is designed to carry the vehicle manufacturers maximum load rating and still have about 2-3 inches of travel before it gets to the jounce rubber. At the jounce rubber contact...that is typically a 2G vertical load input....so, at the jounce contact you are at about 2X the maximum manufactures load rating of the vehicle suspension. On flat ground and slower speeds....you can easily carry about 2X the suspension rating.....thus 1/2 ton pick-ups can carry 1 ton....but you have to be very careful of the road load inputs because you now have no/very little additional travel for road loads on top of the static load.
I once carrier 3100 lbs of sod in a 1/2 ton HD "work truck" pickup about 15 miles..... but I put a lot of the sod way up front stacked high in the bed to try to shift some load onto the front suspension. It still had about 1 inch of travel to get into the jounce rubber. Tires at 60 PSI. Very flat bumpless road.
Now.....if the air shocks fail with a big load on them....you may have some suspension travel issues......might have to move some of the load around....or leave a pile of pennies on the side of the road....pray they are zinc!!!! |
Edited by - c140cessna on 02/10/2009 17:13:13 |
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TXTim
Penny Hoarding Member
629 Posts |
Posted - 02/10/2009 : 19:37:10
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| Hardcore!!!! |
Beer is my currency. |
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highroller4321
1000+ Penny Miser Member
USA
2648 Posts |
Posted - 02/10/2009 : 19:43:04
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quote:
Originally posted by c140cessna
Now.....if the air shocks fail with a big load on them....you may have some suspension travel issues......might have to move some of the load around....or leave a pile of pennies on the side of the road....pray they are zinc!!!!
Thats freakling hilarious! |
Copper Penny Investing
www.portlandmint.com |
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scooter
Penny Pincher Member
240 Posts |
Posted - 02/10/2009 : 20:54:31
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| thats awesome |
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vrbsroma
Penny Collector Member
394 Posts |
Posted - 04/04/2009 : 19:00:53
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| that shows some "real" dedication! |
As far as I know, it is stated "In God We Trust" on the US dollar. How can I trust this currency if I do not believe in God?
Possession is nine-tenths of the law.
When I give my two cents, they're always copper! |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 04/04/2009 : 20:45:30
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| What about the stress on the transmission and power steering? If I want to haul large loads in my vehicle I need an upgrade for cooling the transmission and power steering. |
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Installed Air Lift Shocks on my MiniVan
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