Suspension confusion

[bkahler]

After toying with the idea of using the 345 air ride suspension on my Argosy motorhome I've given up on that idea because I would lose my 25 gallon auxiliary fuel tank. I can use after market Helper Springs that are bolt on. The original fuel tank is only 28 gallons so adding 25 more with the auxiliary tank is something I would rather not do without

So I've been trying to find the correct replacement springs. The Chevy ID tag on the firewall lists the GVWR as 10,500 lbs with the front at 4,300 lbs and the rear at 6,200 lbs. However there is an Airstream supplied tag on the dash that lists the GVWR as 11,800 lbs with the front at 4,300 lbs and the rear at 7,500 lbs. So which one do I believe?

Looking at the rear springs that are currently on the chassis they are made up of 8 leafs and a 3" stack height. The closest I can come at Rock Auto is 8 leafs with 3" stack height and a weight rating of 3,390 lbs or 6780 lbs for the rear axle which is close to the Chevy listing.

The only option that gets me close to the 7,500 lbs that Airstream quotes is a 11 leaf with a 4-3/8" stack height and a weight rating of 3,760 lbs or 7,52 lbs for the rear axle.

I'm inclined to go with the up-rated 11 leaf springs that get the chassis to the Airstream rating. I do plan on using the Argosy to tow a larger enclosed trailer so I'm thinking the 11 leaf springs might be the way to go. However if I use the Helper Air Springs they are good for 5,000 lbs which would negate the need for the heavier springs.

So, what do I do?

Brad

[Smartstream]

Brad I think I would put that decision off for a long time. Put the coach together and set up as you will use it and the drive it to a scale house. With the weight numbers in hand go to a competent spring shop and have a set of springs built for your intended use. Specialized use situations like yours aren't always best served by an on-line generic supply house.

Cheers, Dan

[idroba]

Smartstreams advice X 2.

[LimeyRich]

LOL. Yep Brad, there's plenty of mystery in these Airstreams/Argosys!
While agreeing with Smartstream, I would like to add to his answer, and present a slightly different scenario;
Are we assuming that there is only one temper and spring rate for spring steel? Further that the steel used in the springs on your Argosy is the same temper and spring rate as that used by RockAuto's supplier?
I think that is highly unlikely. I would suspect that a different alloy spring with a stronger spring rate (supplied by a small spring shop), would be right in the average motorhome builders play book. And, why bother to note the difference? Obviously very few motorhome companies ever cared about there product specs' for the future..
So back to Smartstreams suggestion. Go to a frame and spring shop that works on large vehicles, and see what they say. Ask about adding air suspension, as well as certifying the load capacity of your current setup.
(The improved ride of air is well worth it.)

All the best! Cheers! Rich.
P.S. Been taking a break from being under my 345.

[vswingfield]

Y'all can say what you like. I know I don't want to bring up the words spring shop and motorhome to Brad.

[LimeyRich]

That sounds like a personal problem. I can't help with that,
I have too many of my own!

[bkahler]

Originally Posted by Smartstream

Brad I think I would put that decision off for a long time. Put the coach together and set up as you will use it and the drive it to a scale house. With the weight numbers in hand go to a competent spring shop and have a set of springs built for your intended use. Specialized use situations like yours aren't always best served by an on-line generic supply house.

Cheers, Dan

Well Dan, I really hate to say it but you do make sense

Only one potential problem, I won't have the enclosed trailer by the time I start driving it. But I do have the other trailer already which might be enough to work with.

Well, that saves me $400 for the time being.

Thanks!

Brad

[bkahler]

Originally Posted by LimeyRich

...Are we assuming that there is only one temper and spring rate for spring steel? Further that the steel used in the springs on your Argosy is the same temper and spring rate as that used by RockAuto's supplier?
I think that is highly unlikely. I would suspect that a different alloy spring with a stronger spring rate (supplied by a small spring shop), would be right in the average motorhome builders play book. And, why bother to note the difference? Obviously very few motorhome companies ever cared about there product specs' for the future..

I was more or less working under the assumption that suppliers would match oem spring rates, number of leafs, etc when marketing their products. Maybe that's not the case after all.

So back to Smartstreams suggestion. Go to a frame and spring shop that works on large vehicles, and see what they say. Ask about adding air suspension, as well as certifying the load capacity of your current setup.
(The improved ride of air is well worth it.)

All the best! Cheers! Rich.

As for adding air ride suspension the only kind I think I would want to add is the style that rides on the side of the frame rails as shown in the link I provided in my original post. There is an auxiliary gas tank in the space where the typical 345 air ride suspension would need to be located and I would rather have a larger fuel supply. Especially since I can add the supplemental air bags for about $300 and it's a bolt on.

P.S. Been taking a break from being under my 345.

Everyone needs a break now an then!

[bkahler]

Originally Posted by vswingfield

Y'all can say what you like. I know I don't want to bring up the words spring shop and motorhome to Brad.

Yeah, best not to wake a sleeping dragon...

[LimeyRich]

Brad:
What I was saying is that Argosy probably got their "uprated" springs specially made from a small spring business. At least until the late 80's Columbus Ohio had a custom spring making shop that would make a run of any spring you wanted.
That's likely what Argosy had done to get the load capacity, and fit the standard P-30 axle and shackles.
Now you get to figure it out.
I was also thinking pick-up truck "Air-ride", like the set on my F-100, $250 and an afternoon = 5000 lb xtra capacity. At low pressure it improves the ride too.
All the best. Rich

[Smartstream]

Brad remember that matching the factory spring specs is matching some pretty old technology. I would guess that you don't have a really good idea of how the springs you have will handle the trailer you plan to tow. I just have to guess that you want to make some improvement over the factory springs. I'm not saying all spring shops are great, but a lot of them are pretty sharp.

As to the air suspension, the bags on the side are helpers and will do nothing to improve ride quality. I have no idea how the ride is with the short wheelbase but air is the shortest route to a smooth ride. Maybe carrying a few extra gas jugs in the big trailer will solve your auxiliary tank problem. Life is full of compromises.

Good luck, Dan

[ROBERTSUNRUS]

Hi, I say go to a good spring shop too. We have a good spring shop in Long Beach, [Long Beach Spring and Forge] I had them re-do the springs in my 1959 Galaxie. They re-tempered, re-arced, and added one leaf. This raised the rear slightly, allowed for more load in the back seat or in the trunk, and rode smoother.

[Smartstream]

Originally Posted by ROBERTSUNRUS

Hi, I say go to a good spring shop too. We have a good spring shop in Long Beach, [Long Beach Spring and Forge] I had them re-do the springs in my 1959 Galaxie. They re-tempered, re-arced, and added one leaf. This raised the rear slightly, allowed for more load in the back seat or in the trunk, and rode smoother.

That's funny Bob. About 25 years ago I reshaped the springs on my Model T Speedster and I took them to Long Beach Spring and Forge to be normalized/tempered. They were a very old shop back then and I think they are still going strong today. It really is a small world.

Cheers, Dan

[bkahler]

Originally Posted by Smartstream

Brad remember that matching the factory spring specs is matching some pretty old technology. I would guess that you don't have a really good idea of how the springs you have will handle the trailer you plan to tow. I just have to guess that you want to make some improvement over the factory springs. I'm not saying all spring shops are great, but a lot of them are pretty sharp.

Yep, I have no idea how well the springs will support the addition of the trailer load. I know it has towed in the past but no idea what.

I'll have to start checking out the area for spring shops. South of me about an hour is Somerset KY which is a hot bed for hot rodders and the like so I'm betting something can be found there.

As to the air suspension, the bags on the side are helpers and will do nothing to improve ride quality. I have no idea how the ride is with the short wheelbase but air is the shortest route to a smooth ride. Maybe carrying a few extra gas jugs in the big trailer will solve your auxiliary tank problem. Life is full of compromises.

Good luck, Dan

I installed the side helper air bags on a previous 20' motorhome that we had and it did improve the ride. I know at least one other Argosy 20' owner that has them. I'll see what they think of the ride.

I've never been a big fan of carrying external gas cans. One of the trailers I will be using is an open trailer which would make extra gas cans a hassle.

Maybe I can make a real long skinny gas tank and fit it up along the frame rail

Thanks!

Brad

[Smartstream]

Originally Posted by bkahler

Yep, I have no idea how well the springs will support the addition of the trailer load. I know it has towed in the past but no idea what.

I'll have to start checking out the area for spring shops. South of me about an hour is Somerset KY which is a hot bed for hot rodders and the like so I'm betting something can be found there.



I installed the side helper air bags on a previous 20' motorhome that we had and it did improve the ride. I know at least one other Argosy 20' owner that has them. I'll see what they think of the ride.

I've never been a big fan of carrying external gas cans. One of the trailers I will be using is an open trailer which would make extra gas cans a hassle.

Maybe I can make a real long skinny gas tank and fit it up along the frame rail

Thanks!

Brad

I suspect if your overloads made much of a difference, that you were overloaded to begin with. Many of the mohos back then didn't much payload capacity.

I'd look for a spring shop that deals with trucks rather then hot rods, remember you P-30 did start out as a truck.

Also look to I think the 70's and 80's vintage Chevy pick ups. Somewhere back in that era they had gas thanks that ran along the frame rails. I don't remember if they were inside or outside of the rail but it might be a start. I had a 82 Chevy diesel with twin tanks and it was a pain in the rear to fill because there was one fill pipe on each side of the truck. If the pump didn't have a long hose you had to turn the truck around to fill the other tank.


Good luck, Dan
Cheers, Dan

[bkahler]

Originally Posted by Smartstream

I suspect if your overloads made much of a difference, that you were overloaded to begin with. Many of the mohos back then didn't much payload capacity.

Now THAT wouldn't surprise me a bit!

I'd look for a spring shop that deals with trucks rather then hot rods, remember you P-30 did start out as a truck.

Actually Somerset has quite a lot of automotive industry related businesses. Especially compared to Richmond which has zilch

I do know of one big truck service repair shop that is between Richmond and Somerset that I'll be checking out. They've actually worked on an F350 that we had and did a good job.

Also look to I think the 70's and 80's vintage Chevy pick ups. Somewhere back in that era they had gas thanks that ran along the frame rails. I don't remember if they were inside or outside of the rail but it might be a start. I had a 82 Chevy diesel with twin tanks and it was a pain in the rear to fill because there was one fill pipe on each side of the truck. If the pump didn't have a long hose you had to turn the truck around to fill the other tank.

I had an 81 Chevy dually pickup that had the fillers on each side of the bed and you're right that was a royal pain in the....

Looks like I'm going to shelve the rear suspension for a while and as you suggested get it running first and see where things stand at that point.

Thanks!

Brad

[Jenniflow]

Great thread. I have been thinking about this stuff a lot, because I finally decided to keep my moho and take her to Baja (YAY!), after learning she wouldn't smog legally in CA and still have any power, so I am about to head 1500 miles south with no air suspension on a 1986 345 moho.

I really want to be able to take some furniture with me in the coach but I'm nervous about putting any extra weight in. I'm not towing. Would retrofitting the air suspension help me carry more weight? Or are the leaf springs, which have been checked, be adequate to an extra 500-700 pounds?

BTW, I'm figuring I'd do the trip on relatively low water in the tanks and using public facilities , mostly, and I certainly don't have to fill the gas tank every time. I'll probably remove the two barrel chairs and side table for extra room and weight allowance and I'm not carrying a full complement of household goods, clothing, etc. Not sure how much all that would have weighed.

Any thoughts on this?
Thanks!

[bkahler]

Jenny,

Don't make the trip without fixing the air suspension. I think you'll regret it if you do. I'm assuming your 86 345 is like the 86 345 that I dismantled which is the same as on our 84 310. If that's the case then you'll find that without the air bags you don't really have a rear suspension at all. We bought our 310 in Savannah Georgia and drove it 750 miles not knowing anything about the air suspension and how it worked. The PO filled the bank (compressor wasn't working) and the ride was great until the air ran out of the tank. At that point the leaf springs started banging against the bottom of the frame. The ride went from the best to the worst in about 2 hours.

The problem is when Airstream retrofitted the air suspension to the chassis they cut the back half of the leaf spring off. The air ride then attaches to the back portion of the leaf spring where it was cut off and that's what provides the smooth ride. With the air bags deflated the end of the cutoff spring bumps against the bottom of the frame. At a minimum it creates a rough ride, at worst it can damage things.

Even if you don't get a working compressor I would at least replace the air bags and get your pressure tank to work. That way you could stop at gas stations to fill the tank as the air is depleted. The reason the air depletes is because as the suspension moves up and down the leveling valve either fills the air bags with air or releases air to atmosphere. Once the air pressure in the tank drops below the point where the leveling valve is calling for more air the valve stays open and the tank empties.

Bottom line is I would strongly recommend you get the air suspension to work properly, you'll be happy you did!

Sorry to be the bearer of bad news....

Brad

[Jenniflow]

Man. Well, good or bad, that's exactly the kind of info I was looking for. Thanks Brad!

I was hoping I could make it down to the spring place you guys mentioned in Long Beach but that's a full days drive for me. I've already driven it about 6 hours total, on various trips, and it's bumpy. I guess I'm already pushing my luck.

It would be great if I could find a good spring shop around here. They would do the suspension, right? Or do I have to go to another kind of shop? Like truck service? Or who?

Wow, this is the slippery sloppery slope of vintage maintenance.
Jenny

[bkahler]

You can bet that it's been driven without the rear air suspension working previously. I know for sure that our's had been driven that way before we got it. You can't get very far on just one tank of air.

I'm pretty sure that having the springs beat against the frame can cause loose rivets. Our 310 had a bunch of interior rivets that were sheared off and I know that since I fixed the air suspension I haven't noticed any new rivets missing.

I would think any truck type service shop should be able to repair the suspension. If you can't find any place local just drive slow until you get it repaired. Better safe than sorry.

As they say, the price you pay to buy the motorhome is just the down payment

Good luck!

Brad