Friday, March 23, 2012

Rock, Bounce and Roll - Suspension Rebuilds

Just Before Purchase
When I first bought my Aero Cruiser I had the "opportunity" to drive it from three hours north of San Francisco to my home base 90 miles north of New York City, about 2,700 miles. Probably due to the excitement of that trip I thought that it handled pretty well. Nope, I was WAY wrong! It's a small miracle I made it back without being catapulted off the road or at least bounced into oncoming traffic at 70 miles per hour.

Original Front Suspension
After much research I decided to renew and upgrade my suspension bits. After all, it was a four-wheel basic design with leaf springs and supplementary air bags in the back and coil springs with a transverse mounted helper spring in the front. All the info I found led me to believe I had what amounted to a Dodge one ton pickup truck in the front and rear. How hard could it be to get parts for THAT? Read on.

Anyone who reads this column knows that Murphy is indeed an optimist, at least in respects to my ongoing projects. When ordering the front suspension parts it seemed there were several models of Dodge pickups that use different suspension parts. Okay. . . which one do I have? My Aero Cruiser sources assured me I had one type, although the photos of my rig were different. I went online and ordered both types, figuring that would be safe. I could always send the wrong ones back. By the way, is anyone in the market for a set of front suspension parts for a Dodge pickup, circa 1990? Yup, still have them. It turns out I have the only Aero Cruiser with the 4,000-pound version of the suspension and it uses totally different parts.

Rear Leaf Spring and Shock
That being sorted out, next up was the rear leaf springs. After looking through the online parts books I couldn't find ANY Dodge parts that would meet the load carrying capacity I needed. You know why? They're NOT Dodge springs! Turns out they are GM springs mounted upside down. Do not ask how long it took me to figure that out! On the up side, the heaviest duty versions were perfect for improving the ride and ride height in the back, and weren't all that expensive. Of course shipping on something that heavy is highway robbery!

Once all the parts arrived, dis-assembly began in earnest. Since this job required some heavy duty and specialty tools, I engaged the assistance of my favorite local shop where the guys are familiar with all sorts of heavy duty tools. They're a great great bunch of guys. I highly recommend them if you are in the area! Honest, too!

Suspension Off, Transverse Helper Sprng On Floor
We began by removing the front wheels and the brake assemblies. Next we tried to remove the upper and lower ball joints and control arms but couldn't do anything until the transverse helper spring was removed! They wouldn't come out. I will not make that mistake again! After everything was cleaned up, all new bushings were installed and the new upper and lower ball joints, control arms, tie rod ends and shocks were fitted and adjusted.

New Leaf  Spring On Top
On to the back. Did I mention these giant leaf springs are HEAVY! It's a good way to lose a toe, not that I know that first hand, but hey. . .

We used multiple jacks to hold the load, as the springs were removed one side at a time. It turned out the bushing on the shackle mounts was slightly different from the originals. Understandably, the design had changed a little after more than 20 years. We had to drill them out to a larger diameter to fit on the mounts. Not too bad as far as random difficulties go. Rear shocks were replaced too. I was amazed that the shocks were all well under $100 each. Thank goodness for the additional small miracle.
New Coil Spring On Left.

Once mounted, the RV was riding two inches higher in the rear. The leaf springs had compressed quite a lot in the intervening years. I was also two inches or so higher in the front, which really helped with wheel well clearance.

The guys rough aligned the RV and I took it home. Now to find an alignment shop that could do a proper alignment. As usual that, sounds easy but isn't. The nearest one was 45 miles away, over the mountain. Thankfully the handling wasn't really all that bad and I could get there without flying off the mountain, down the 1,000 foot drop-offs.

Riding MUCH Higher!
The first alignment didn't work; the numbers I was given were wrong. The second one worked better, but the steering wheel wasn't centered and the coach pulled to the right.

The third time was the charm! With everything setup correctly and a new heavier duty suspension, this thing handles well. Like night and day. Better than when I bought it. Maybe even better than from the factory since I used newer technology with improved parts.

For any older coach that is feeling a bit "saggy" or whose handling isn't up to par, I highly recommend this process. It isn't all that expensive, yet pays big dividends in drive-ability. You may even pick up a bit more load carrying capacity in the bargain!

Be Seeing You...Down the Road,

Rich "The Wanderman"


  1. I'll be playing the suspension game myself here pretty soon, sadly, I can't find a good deal on a set of 8-leaf packs to replace the factory original 6 leaf packs, so I'll be going the less expensive route by adding to the existing packs myself ($70 vs $700) and repairing the damaged air spring assembly on the driver's side (I bought a new bellows, will also be replacing the fittings and the air line to ensure that it won't cause problems later).

    1. Big Matt,
      What kind of leaf springs do you have? Often a Heavy Duty version can be had if sourced for a different vehicle. Many trucks use the same leaf springs as our RVs. Is there a number stamped anywhere on the spring itself?

      I have a leak in my rear right hand side airbag "DOWN" valve. They are mechanical valves, and I am going to try and rebuild it if possible. It's a real P.I.T.A. to have to add air every 15 minutes or so when driving.

      When you replace the lines, make sure you use some anti-chafing sleeves to prevent rub through.

      As always...a great comment!

      Rich "The Wanderman"

    2. Standard 6 Leaf HD Pack that came with the early 90s Dodge 3/4 HD and 1-ton trucks.

      Wanted to go to an 8 Leaf pack, but they're out of this world expensive these days, so I'm going to the BDS add-a-leaf pack, which adds a bottom curved leaf to the main pack (you replace the pin and reassemble the pack to do it) that's the equivalent of two additional thick leaves.

      I will likely get a new set of Ubolts and the BDS add-a-leaf kit for the front spring packs as well to help level the truck back out and to keep the front suspension from bottoming out as much (current front pack are simple flat 3-leaf packs that bend upwards when loaded because of the Dana 44 solid front axle).

    3. Correction, they're the 6+1 (The +1 refers to the flat spring at the very bottom of the pack).

      I wanted to go to an 8+1, but was priced out of the market.

    4. Big Matt,
      I thought I had those, but it turned out to be GM 1 ton+ springs hung the opposite way from stock! I went with the heaviest duty versions I could find. That plus the rear airbags made the ride pretty decent. And I picked up a bit of load capacity.

      The add-a-leafs are long proven tech. I had them in a Barracuda back in the day. Just make sure everything is secure and won't shift.

      What about air-bags?

      Rich "The Wanderman"

    5. Already have a set of AirLift 5000lb set on the rear, however, the air bag assembly has been carrying the brunt of the load vs the leaf spring pack and because of such, a really bad bottoming out cause a slow leak to form in the driver's side bag.

      So, I'm adding some extra steel to the equation to reduce the percentage of the load carried by the air bags, which are currently being run at 80 PSI or roughly they're carrying 4000lbs.

    6. Big Matt,
      I was in EXACTLY the same place as you. Now I run 20-40lbs in the air bags and haven't managed to bottom out yet!

      Rich "The Wanderman"

  2. who needs leaf springs, timbren offers a great air suspension adaptable to any of our coaches. As for the 4000 lb dodge front end, I have no problem finding parts including where I got all needed to go thru my 92 Europa front end.

    1. Unknown,
      Air bags are fine, if you can guarantee you will have a supply of air for them and they won;t ever leak. A flat airbag in the middle of nowhere without a replacement (and all the tools and jacks needed to get the coach off the ground) is useless. Leaf springs with air bag assist/leveling gives you the best of both worlds.

      If you had read the article carefully, you'd see that sourcing the parts for the 4000LB IFS front suspension was easy, IDENTIFYING which suspension it is, was the hard part.

      Rich "The Wanderman"

  3. Hi Rich,
    Thanks so much for sharing your experiences with the Aerocruiser. I have a late 1989 Amera Coach II built in Indiana that has a very similar front suspension wih the Helwig helper transverse spring. Called Dodge dealer today and was informed that springs are discontinued. Where did you get your springs please?

    1. NOLA John,
      I did A LOT of research to find the perfect coach for me. the Aero Cruiser was it. Thanks for the compliment. Are you on the east coast?

      I ordered the springs from Rock Auto, be VERY careful there are a few different versions and my coach had a VERY unusual set from the 4000lb front axle setup NOT the 3600lb version that every other Aero (and maybe Amera) had. The rears are GM parts and should be available from the same place. I would look around and find the best deal on the version of the spring you want. I went with the Heaviest Duty version, but this may not be right for your use.

      Rich "The Wanderman"

    2. I too did a fair amount of research for a compatible RV and Aero/ Amera seems like a very good fit. Small in stature and motor, but big in component choice and sensible design. Perfect ceiling after all these years, though the Eterna Bond treatment for seams is next on the list!
      I just ordered the Spectrac front units on advice of a gentleman who had worked with the AeroCruiser tech specialist George K. and suggested that their springs would negate the need of the Hellwig helper transverse unit.
      Odd, but my late 1989 Amera Coach II has the front end spec'd at 4400 lbs on the GVRW tag. All suspension components appear exactly as yours right down to the leaf spring count.
      One option for rear suspension that I'm considering is rearching the original springs by a local chassis specialist. Depends on whether or not they heat treat them. My coach did not have air bags for rear suspension adjustment, just an additional set of helper leaf springs. Not sure whether I'm going to add the air component.
      I live in New Orleans, and have a fair number of resources available. Trusting them is another matter!

  4. John,
    I would add the rear air bags. It adds quite a bit of versatility to the load distribution and ride. Also, can be used to level the coach for uneven load/terrain.

    They are quite reasonable in price as well.

    Rich "The Wanderman"

  5. Awesome looking RV! This is my idea of what a motorhome should be. At 23' in length, it's short enough that anyone with a driver's license can drive it. I'd buy one if I knew someone who was also an Aero Cruiser enthusiast.


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