Rear Suspension

[Warbs]

We just returned from visiting New England, New Brunswick, Nova Scotia, Newfoundland, Quebec and Ontario and we realized that our rear suspension needs help. Travelling on the scenic back "roads" caused the rear of the motorhome to shake the interior contents continuously. Has anyone any experience with the "helper airbags" that go between the frame and the leaf springs? We weren't overloaded and, as far as I know, there is nothing broken in the rear suspension. We would be hoping for a little bit softer, more forgiving suspension. FWIW 1977 is the last year with the leaf springs.

[Inland RV Center, In]

New rear air bags are available. Not cheap, but they are available.

You could also have a rear wheel-tire balancing problem.

Andy

[uwe]

Originally Posted by Warbs

We just returned from visiting New England, New Brunswick, Nova Scotia, Newfoundland, Quebec and Ontario and we realized that our rear suspension needs help. Travelling on the scenic back "roads" caused the rear of the motorhome to shake the interior contents continuously. Has anyone any experience with the "helper airbags" that go between the frame and the leaf springs? We weren't overloaded and, as far as I know, there is nothing broken in the rear suspension. We would be hoping for a little bit softer, more forgiving suspension. FWIW 1977 is the last year with the leaf springs.

Sounds to me more like an imbalance somewhere, ore even bad shocks, or all three.
I would check tires first, then tire balance, then drive shaft, then shocks.
Whenever my cargo can got the shakes in the rear, it was usually one of those three things. If you did not have air bag suspension originally , then I see no reason why you would need them now.

[Warbs]

Thanks for the prompt replies. I should have explained things better. Six new michelin tires with beads inside for balancing them. Four new shocks and new airbags inside the front springs.
The problem seemed to be that the rear suspension had no "give" to it . Any road that wasn't in perfect condition caused the rear end to ride harshly and bounce around.
We weren't purposely thrashing the motorhome or trying to make time but the ride seemed, IMHO, very poor.

[Inland RV Center, In]

Warbs.

I seem to recall that the 28 foot Argosy motorhome, did indeed, have a very rough ride.

Best I remember, the fix was to eliminate the overload leaf spring and install air bags with automatic leveling.

Andy

[thenewkid64]

Were you running "dry" to conserve weight? Meaning how much water e did you have in the fresh water tank. It is in the rear on most of these and at the very end of the frame. Carrying that weight back there "loads" the suspension and will help to reduce the bone jarring ride. I had a 76 Argosy, it rode progressively rougher the further below 1/2 tank of water we were.

My 78 is smooth as glass but it has the first Airbag Only rear suspension system that I am aware of on the P30 style chassis. Airstream always was a pioneer.

[Warbs]

Thanks for the info. We were travelling with approx. 1/4 in the fresh water tanks and both waste tanks near empty. In some areas we were travelling we weren't sure if we were going to be boondocking or staying in campgrounds. I bet you're right in that we need to keep some more weight back there. I'll certainly try that before I spend big bucks to modify what I've got.

[overlander63]

Originally Posted by Warbs

Thanks for the info. We were travelling with approx. 1/4 in the fresh water tanks and both waste tanks near empty. In some areas we were travelling we weren't sure if we were going to be boondocking or staying in campgrounds. I bet you're right in that we need to keep some more weight back there. I'll certainly try that before I spend big bucks to modify what I've got.

How much pressure are you running in your rear tires? Most new tires have a higher rating than what was OEM, and they will carry more weight, at higher pressure. If your MoHo is supposed to have 65psi in the rear, and the tires hold 80, and you are running 80, it will dramatically and adversly afect the ride (rougher). Try reducing the tire pressure to recommended pressure, if it is higher, and drive it agin, and see if it rides better. If it still rides like a tank, you may well have to take Andy's advice, and remove a leaf, and install airbags.

[Warbs]

I was keeping all tires and the front airbags at 75 psi. The tire guy thought they were a bit underinflated. He said 90 or 95 would be about right. The front suspension was fine, it was just the back of the bus that seemed rough.

[dwightdi]

The higher the pressure in the tires the harder it will ride. Same way with springs and air bags. Stronger is not better. The quality of the shocks are the thing I would look at. Bigger shocks that absorb more energy and softer springs which allow movement for the shocks to absorb is the way to go for better ride. I took the same tour and the roads are not good. My 77 Soveriegn took a beating and had some major rivets fail. I attribute it to the rough roads and the fact that it was the first trip with my full ton dually that has a rather stiff suspension in the rear. The old 3/4 ton van absorbed more of the shocks rather than transmitting them to the trailer.

[GlenCoombe]

Hey Warbs, where do you live?? I'm a refuge from the Canadian tax man. Went to high school at Midland and Churchill. I lived at Midland and Eglington.

[ALANSD]

I guess your tires require the higher psi? I use 60 in my goodyears, and with my now( hallelujah) functional rear airgbags and little or no water in the tank I get a smooth ride, with only occasional "crashing" over ruts when at slow speeds off the hiway. Mine has leaf springs as well, which I keep lubed.
There are retro fit airbags if your model doesn't have them..the ones I have seen are mounted over the leaf spring and are not very expensive.JC WHITNEY and many camper parts houses carry them.

[74Argosy24MH]

Shocks will also make a lot of difference, some are very stiff compared to others, do you know what brand you have?

[thenewkid64]

According to the data plate on the fire wall of my coach. I run the the fronts at 70, (Plate says 60, but I don't drive 55) and the rears at 55 PSI (plate says 45, but there again is the 10 MPH plus I run)

The rule of thumb I was taught is add 10 PSI for every 10 MPH over 55 you normally drive, if the vehicle was originally designed in a 55 MPH MAX time frame. The tires will not heat up as fast, and they will wear better. Of course there is a theoretical max

I would also set the front air bags to 55 PSI. That is what they are supposed to be. Too much pressure in these and you will experience a rough ride and will wear the outside edges of the front tires as they will lift the nose and mess up the camber on the wheels.

I think you will be pleasantly surprised at what a difference less PSI will make. In this case more is not better.

[Warbs]

Thanks for all the info, I didn't realize I opened up such a can of worms!

Some answers to questions GlenCoombe- McCowan and Ellesmere. ALANSD- I'll try 60psi and see what happens. Luckily we have lots of rotten roads nearby for some comparisons. 74Argosy24MH- I put on four of the yellow Munro"Gasmatic" shocks last fall. Are they any good or what would you recommend? thenewkid64- I noticed the front of the Argo was a bit high but I thought it was the back end drooping!
I can't stress enough how valuable this website is, I learn stuff every time I log on. Thanks again.