variable weight rear springs?

I am in Grand Junction CO with our OCC and Airstream. As many of you know from a "off topic" log of the first few days of our trip I was very happy with the four new Bilsteins and the Airlift 1000 for towing. After 1738 miles I think when I get home I will go one step further and replace the stock springs. Someone told me that I should, but went with the onboard compressor and the AL 1000. I seem to be sitting lower than I want, and lower than when I started the trip.

I am going to adjust my hitch up a bit to get sometongue weight off.

part number for the variable weight springs some of you have added? Where do I order them? I will use the AL 1000 too, but need help.

I will post some more photos in my Crusin' log but here is one for fun. We are camped on the State beach in Mendicino CA.


The OCC has pulled the trailer great up several mountain passes. The steepest climb was 500 ft in Sacramento up over Donner pass 7327 ft to Lake Tahoe. It never heated up at all and pulls the grade at 55-60.
COL

Check that the airbags from the stock springs will work with the other springs. Let me know if you ever come out east in your travels.

CC623 is the Moog variable rate. Rockauto carries them.

COL:

Careful there. Variable rate springs tend to be softer in the first 2 inches of travel and tighten up further down. If your towing with an Equalizer and want to maintain ride height your no further ahead with variable rate springs. Its best to get the the proper spring. Your local parts house will have the load charts.

Had the same ride height problem using the bags so ended up going back to airshocks. What works best is to get the highest load rating spring available. Any parts store should have spring catalogues. If you start with the exact replacement, the book will show you all the specs. changing coil thickness, number of coils while maintaining the same mount specs and outside dimensions, you will have a choice of load rating for essentially the same spring. Any parts guy worth his salt should be able to work you through it.

I ended up with a set of HD springs from a Buick sedan for my Caddy and they worked great. Load rating was 300 lbs higher than stock but with the same ride height. Barely put 50 PSI in the shocks now with the trailer hooked up. 130 lbs before.

Bill

Thanks Bill. I re-read your postfrom before I left on the trip. I have another 1700 miles to return home. I will look into the heavier springs when I get back.

I love the stabillity and performance of the Bilstiens so will stick with them for now. Withno trailer and 8 lbs in the bags I do not scrape the street when I back out of my driveway.

With my equalizer I can adjust the height of the ball up a bit (I lowered it 2" after I put the Airlift bags in) That made the trailer level with the bags inflated to about 25 lbs.

Two inches makes a big difference in the balance of the trailer.
Thanks for the tip. It is a fine line..........
Dick

coil spring catalogue

stock rear spring: 5417
cargo coil: CC623

Bill is right: cargo coils are progressive springs, so their initial rate is quoted in the above catalogue but they get firmer and firmer the more they get compressed. Just the weight of the car puts them in their "working range".
I would have thought the CC623s would be right up your alley since their initial rate is basically on par with the stockers but but their final rate is much firmer than stock. However I have NO experience whatsoever with towing so keep that in mind, so if Bill has BTDT, then you might want to look into getting a firmer (higher rate) set of linear rate springs with a much higher load rating, like the 8535, 8389 or 8543.

While convert2diesel might be right about how the 623's work I disagree on the fact the you would see no improvement in ride height over the stock springs. I have run the cc623's in all my wagons since the late 80's, even tho I never really towed anything of much weight (heaviest would of been a empty bobcat trailer) I have loaded mine with over a ton in back a few times.

A couple things I have noticed with the 623's is that empty they ride a little over an inch higher in the back compared to stock which gives it a slight rake and are noticeably stiffer which really cuts down on the sway from the back end. When I got my latest wagon the 1st things I got for it was decent tires, Bilstien shocks and cc623 rear springs even tho I will never haul near the weight my other wagons saw I like the way they handle and raise the rear so I won't drag on steep drives.

Here are a couple pics to show the difference between the stock rear springs and then with the cc623's taken in the same parking space. You can see the difference by looking at the rim to the wheel opening.

90 % of the time I drive the car as our daily and 5% we will be towing and 5 % hauling stuff in the back. So I don't want to jar my teeth out. This shows how I was riding a week ago 300 miles into the trip with 25 lbs in the Airlifts...........




now I am sitting lower so don't know if the bags leaked or the stock (62,000) springs have compressed.

dick

Ancient_1 wrote:

While convert2diesel might be right about how the 623's work I disagree on the fact the you would see no improvement in ride height over the stock springs. I have run the cc623's in all my wagons since the late 80's, even tho I never really towed anything of much weight (heaviest would of been a empty bobcat trailer) I have loaded mine with over a ton in back a few times.

A couple things I have noticed with the 623's is that empty they ride a little over an inch higher in the back compared to stock which gives it a slight rake and are noticeably stiffer which really cuts down on the sway from the back end. When I got my latest wagon the 1st things I got for it was decent tires, Bilstien shocks and cc623 rear springs even tho I will never haul near the weight my other wagons saw I like the way they handle and raise the rear so I won't drag on steep drives.

Here are a couple pics to show the difference between the stock rear springs and then with the cc623's taken in the same parking space. You can see the difference by looking at the rim to the wheel opening.

I think where the confusion here is the desired ride height loaded. Typically people don't care if the rear sags a bit when your coming home from the building supply house, but when your using a weight distributing hitch, you want to achieve the same ride height as you do unloaded, both front and rear. The intent is to have the car and trailer dead level when towing.

Springs are rated based upon three things. Installed height (weight of the car only, no extra load), load rating (weight actually on the spring, again with no load in the car) and the spring rate (the extra weight that will compress the spring 1 inch).

Taken from the Moog charts http://www.moog-suspension-parts.com/Universal_Coil_Springs.asp . Col, this is an example of the chart I was talking about in my previous post. Just click on any of the headings at the top of the chart and it will sort the chart by that heading.

CC623

Inst. Height 11.00 inches
Load 865 lbs
Spring Rate 206 lbs/inch

5417 (stock wagon spring)

Inst. Height 8.5 inches
Load 1200 lbs
Spring Rate 157 lbs/inch

5419 (The HD Buick sedan springs I installed on the Caddy)

Inst. Height 9.00 inches
Load 1211 lbs
Spring Rate 173 lbs/inch

What I think you guys have experienced with the CC623 is that the load rating is only 865 so the extra 335 lbs have compressed the spring aprox. 1.5 inches (335/203) giving you an installed height of 9.5 inches (a little higher than stock). From that point on you will have put 412 lbs (203 per spring) in the back of the car to lose another inch if these springs were constant rate. The thing is, the CC623 is a variable rate so the spring rate is probably the average over the entire travel so who knows what it is up at the top and using them with airshocks or bags, defeats the need for a variable rate spring (returns it back up to the softer area of travel). These springs are great for load but I would think they would be a little stiff the rest of the time.

I went to the highest load and spring rate rating available in a constant rate spring for the car to drop the pressure on the shocks (or bags) needed to return the ride height, when loaded, to stock height for trailering with a load distributing hitch. Car rides a little stiffer due to the spring rate but still drives like a Caddy when not loaded and the air shocks handle any extra load applied by the hitch and it doesn't even come close to bottoming out coming off curbs when it is loaded.

Works for me.

Bill

the cheapest place to buy the CC623s , ebay, i paid $38.44 to my door , brand new in the moog box

convert2diesel wrote:

The thing is, the CC623 is a variable rate so the spring rate is probably the average over the entire travel so who knows what it is up at the top and using them with airshocks or bags, defeats the need for a variable rate spring (returns it back up to the softer area of travel). These springs are great for load but I would think they would be a little stiff the rest of the time

I'm almost positive the advertised rate is the initial rate, not average.
You can back it up by the fact that for all linear springs Free Height - (rate/load) = installed height
whereas for all "CC" springs, Free Height - (rate/load) < installed height.

jasonlachapelle wrote:

I'm almost positive the advertised rate is the initial rate, not average.
You can back it up by the fact that for all linear springs Free Height - (rate/load) = installed height
whereas for all "CC" springs, Free Height - (rate/load) < installed height.

Your right. Didn't do the calculation from free height. If they go to installed height at 206 lbs/inch, I have no idea how much it would take further down.

Regardless, we used the CCs in the back of Gords wagon and unloaded it was about 3/4 to 1 inch higher than the locomotive. Car rode like it had 4x4s jammed between the axle and the frame but Gord always had about 5oo lbs of crap in the back so it rode alright and was lower than the locomotive with the added weight. Only had an issue when he emptied out his car. When we fixed the airshocks and compressor, and the ride height was corrected, with all his stuff in the back, it returned to riding like truck again. Ended up pulling the compressor fuse and keeping the stuff in the back.

Never could get it to ride right, so when we did the springs in the locomotive, and again the Caddy, we went with the constant rate springs and had no issues. Towing wasn't an issue with either, re ride height, as long as the airshocks worked. Gords car didn't have a hitch so never had an occasion to try the CCs with the load equalizing hitch. I assume it would have worked but Gords car was just too stiff in the back end.

Bill

Yup:starts out at 206 lb/in uncompressed, so the rate is even higher in the "working range". That is a significant departure from stock. I think the same of the CC623s as you do: way too stiff for an empty daily driver especially one that uses a sway bar. Hence why I use the CC505 in the back. I found the CC507 to be pretty good with the huge 1.5" swaybar as well. It's all pretty subjective though, so more power to the guys who like the CC623s. At 38$ a pair, they are worth it if you're hauling lots of stuff or people.

Thanks for the input Guys. Look at the photo of the OCC with the big blue ox. I have about two inches of space above the front tire. Now I have about 4" or 5" loaded with the trailer. The rear sits too low now so I am going to look into the spring issue when I get back.

We traveled from Utah, through Boise ID, into Eastern Oregon Yesterday. Last leg to the coast today. So far we have traveled 2500 miles in the past 13 days.

What Equalizer are you using? When I first bought mine, a opted for the 8,000 lb unit (trailer weighs in at about 6,000 lbs. with a tongue weight of 630 lbs.) and found I couldn't get the car level with the lighter trunions. Swapped it out for the 10,000 lb unit and it worked better. Still not perfect, but within an inch on the front and level at the back. Still a little light on the front but every thing tracks well now.

With the single axle, you might try some tongue weight modifications till you get home and fix the spring issue. Start with the stuff in the car first because you always want to keep the tongue weight slightly over 10% of total to reduce sway.

Can't wait to get bucks together for a Hensley. The Equalizer is the best of the bunch IMO but the Hensley takes it to a whole other level.

Bill