Thought I would contribute my thoughts on a recent air bag installation I did. And I am looking for some opinions on my WD hitch.
First some background:
-2010 Chevy 1500 with the heavy duty tow package (tranny cooler and some other stuff. Its GCVWR is 15000.
-Towing a 2012 Rockwood Mini Lite 2109s. Dry wieght-3700lbs. Tongue weight 370 (this doesnt include the 40 Gallon water tank mounted in the front ( I think)
-I'm a noob RV'er
We use the trailer when we go dirt bike racing. So I have a dirt bike in the back of my truck with about 10 gallons of water, firewood, tools, gas, generator and all kinds of other stuff... just a quick guess but I think we have about 750lbs-in the bed of the truck.
So when I would hook up my WD hitch, I felt that it was adding too much weight to the front tires. The tongue weight after all is only 370. I would see my front tire pressures rise about 3 psi when using the WD. Its also worth noting that when I do not have a load in the bed, the truck handles the trailer weight really well without the WD. So I decided to install some airbags.
I went with the Firestone Riderite bags and the Airlift Load Controller II.
First on the Airlift. When I first opened the package I thought it was a little rink-a-dink. They used garbage masking tape to hold all the tubing together, the tubing ends weren't cut squarely (which is needed for a good seal). The Gauge was a poor design. Its essentially a gauge and a switch mounted to a plate with all the guts hanging out the back. However and the reason I went with this kit, the compressor was a nice unit that was mounted inside of a protective case. It also allows mounting in many different angles and wasn't so exposed to the elements. The kit also comes with a Low Pressure switch. This is great! because the bags need a minimum pressure to prevent damage. This low pressure switch was also adjustable, lucky for me it came pre-set for 5PSI which is what the Firestone bags required.plus the price was right!
Installation was really easy for this compressor kit. My truck has an empty tray for an extra battery. The bolts that hold the tray lined right up with two opposing bolt holes on the compressor. So I didnt need to drill or use any self-tapping screws. For wiring through the firewall there was only one hole that I could use, but it was accessible. Once mounted, I sealed the system before I connected the bags. I started it up and it worked great. The gauge read 5 psi and I was set to mount the bags
The Firestone bag. This was a great kit, NO Drilling Needed!! Instruction were easy to follow, and all that I needed to do was take weight off the wheels slightly to get them in. The hose supplied was good quality also.
Once everything was connected I tested out the system. First problem, the Airlift gauge is OFF by..guess what 5psi!?! I dont know what changed? I had installed the shrader valve as a backup and double checked with a gauge I know is accurate. So that bummed me out...I will be calling Airlift, to complain and maybe get a new one. So now it was time to load it up and hook up the TT.
It only took about 10 PSI to level the truck out with just the load in the bed. And about 20 PSI when I hooked up the trailer. The front end came up by only .5CM on one side and about 1.25CM on the other. not sure how accurate those numbers are, because I couldn't measure on a perfectly flat surface.
It felt good to load up and not have a saggy rear end. For that the bags were worth it. the other great thing is the ability to adjust the trailer height with a push of a button. this will come in handy in many ways. We are camping in the forest. The roads/locations are never flat. So if I need to get to a spot but the rear of the trailer runs the risk of dragging, well I just drop the pressure!
I would recommend the Firestone bags to anyone interested. The Airlift on the other hand...well if price is an issue, then go for this one. It was $100 cheaper than the Firestone brand. However I did hear great things about the Firestone Compressor kit. It doesnt come with the low pressure switch.
Now here comes my questions. Should I still run my WD bars? I leaning towards not running them. What do you guys think?
First of all, I cannot see how using a WD hitch can ADD 3psi to the front tires! The only way to do that is to put more air in or heat them up.
Second, Yes, I think you should use the WD hitch. Using the air bags will raise up the rear of your truck but they will not replace the weight taken off the front axles by the tongue weight and they also will not relieve the extra weight placed on the rear axle.
It is fine that you use the air bags to compensate for the extra weight in the bed of the truck but you should not expect them to do the job of a WD hitch.
I suggest that you get to a scale and get some axle weights and tongue weight. I think you may be in for a surprise.
Barney
Edit: I thought that we covered this subject pretty well in your previous post about the WD hitch.
* This post was
edited 05/24/12 06:38pm by BarneyS *
2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch
2002 Ford F250 Super Duty, 7.3L PSD Visit our website here
I must agree that adding weight to the truck will not raise the tire pressure. That has to be due to heat or an inaccurate tire gauge.
WDH and air bags are really for 2 different purposes and it sounds like you need both. I would weigh the rig fully loaded with fuel, people, food, firewood, everything. I would bet you are over the truck's GVWR. That isn't necessarily a big deal but it's something to be aware of. The more important question is are you over the weight rating of your tires?
Barney, I forgot all about that thread. Will have to go back and read it through again.
I have a truck that is rated at 15,000 GCVWR. With a 3700 lbs dry weight trailer. You really think I could be over 15000lbs? I am going to try and find a weigh station near me.
I am going to use the WD hitch, sounds like the only way to go. From searching, I will take a measurement with the trailer unhooked and the truck level, then hook up the WD.
Adding weight will compress the tires, which will increase their pressure. If you have a floor jack, check the pressure on a front tire, then jack it off the ground, and recheck. Without the load the pressure will drop.
Load in the bed to the front of the rear axle may be increasing the front end weight proportionally. The only way to check for sure if you need WDH is with a scale.
Chances are the tongue weight is more than 390 if you put any kind of load or water in the tanks of the trailer.
christopherglenn wrote: Adding weight will compress the tires, which will increase their pressure. If you have a floor jack, check the pressure on a front tire, then jack it off the ground, and recheck. Without the load the pressure will drop.
I believe you are incorrect. Adding weight will squish the tire but unless the actual inside area of the tire increases, which it doesn't, the air pressure will remain the same.
Barney
You are correct Barney. The tire DEFORMS. It does not compress...
For the tire to compress, it would need to be contained in some way, "squished" from multiple directions.
The overall interior volume of the tire remains the same before and after. Therefore the air pressure remains the same before and after.
If you are getting different readings it is due to an inaccurate gauge.
2002 Chevy 3500 DRW 8.1L/Allison
2000 Palomino B1500
...and the reason why I need a DRW to haul a Palomino:
2004 United 7x14 tandem axle enclosed toy trailer
2011 PJ 8x20 7-ton deckover equipment trailer
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I believe you are incorrect. Adding weight will squish the tire but unless the actual inside area of the tire increases, which it doesn't, the air pressure will remain the same.
