M375 rear air bags

[turbinebronze]

Hi All,
  I just installed rear air bags on my '69 Travco Mahal. I used Firestone kit #2109, from a Dodge B van. The B van kit was almost a bolt on deal. I had to drill a few holes... Problem was the resting height was to short for the B van bags. (Resting height 4.5 in, the design running height of the B van bag 5.5 in). After speaking with Firestone, they told me to change the bags or run the B van bags at the design height. They also gave me the bag part number to install if I wanted to run at 4.5 inches. After speaking to Michigan Truck Spring, they swapped out the B van bags for the ones I needed for the shipping cost. (Good people at Michigan Truck Spring).
  Now the Travco not does not roll over on it's side in cross winds, and does not have a sharp hit when you hit small bumps. Much nicer to drive.
The B van bag part number is 6781.
The proper height bag # is 6762.

I guess if you are installing air bags, you might want to measure the distance between the mounts and check it against the design running height of the bag you have. My MH is probably sitting lower than new, but I'll never know...and I didn't want to lift the rear of the thing the inch required to run the supplied bags. Firestone told me it would be hard on the bags to run them below designed ride height.

  Hope this helps someone, Craig

 

[Rickf1985]

I think I would have been inclined to run the original bags at a compromise of 5 inches and split the difference. That way you gain back some of your original height which in turn also helps your front end alignment and the rear suspension travel. You may have found that even going up to the design height may not have been uncomfortable since the original springs would still be taking a substantial part of the load off of the bags. It is not like you are trying to lift extra weight above the design height. That is when bags get hard and uncomfortable. The advantage you have is you can always get the other bags and bolt them right in.

[turbinebronze]

Hey Rick,
  My problem with the original bags is that the kit I installed is for a Dodge B passenger van, not an M series Dodge.  I have know way of knowing if the taller bag is the proper ride height. Firestone told me not to run the bags under the design height, that doing do would shorten the life of the bags. So...I only know what I have. I do not know what the design ride height of the vehicle was when new, but she doesn't look like she sets low in the rear.(that kinda sounds crude...)
  I just wanted to let people know the kit hardware that fit, and the bag I used for the height I measured.  You can run the taller bag if your ride height is more.

[Rickf1985]

Gotcha.

[Chief Crazy Canoe]

Is there any chance you have pics of this installation on your M-375?  I've been considering an airbag assist setup for my 72' 24' Chieftain - ours share the same chassis.