Good Sam Club Open Roads Forum: Another Question on Front Coil Springs
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class A Motorhomes

Open Roads Forum  >  Class A Motorhomes  >  Restoration & Vintage RVs

 > Another Question on Front Coil Springs

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Son of Norway

Denver, Colorado

Senior Member

Joined: 10/12/2011

View Profile



Good Sam RV Club Member

Offline
Posted: 04/23/19 03:44pm Link  |  Quote  |  Print  |  Notify Moderator

I last posted a question about replacing the front coil springs on my HR, which is on an '89 P30 chassis. It was recommended that I contact Supersteer, so I went to the website. I weighed the coach on a CAT scale and there was 4100 pounds on the front axle. ( Although I guess I need to fill the coach with food, water etc. to get a more accurate weight.) So let's say that I put another 500 pounds on the front axle once I fill the coach, for a total of 4600 pounds. Supersteer will sell me a set of springs rated for 4600 pounds.

My problem is this: According to AC Delco, the original OEM springs on that chassis were rated at 3289 pounds per spring, for a total of about 6600 pounds. It would seem like the original springs were way too stiff to begin with and the coach should ride like a tank.

The Supersteer rating and the OEM rating don't agree. They have a 2000 pound difference. What's up? I tried to talk with the rep at Supersteer about it but she really didn't have an answer. Did Holiday Rambler replace the original springs with a lighter set during manufacture?

My more basic question whether I should pay $360 for the Supersteer coils or just buy an OEM set for $106. But I don't want the coach to ride like a tank.

Thanks for your wisdom on this one.


Miles and Darcey
1989 Holiday Rambler Crown Imperial
Denver, CO


MountainAir05

New Mexico

Senior Member

Joined: 01/27/2007

View Profile


Offline
Posted: 04/23/19 03:54pm Link  |  Quote  |  Print  |  Notify Moderator

Oem is Oem. Did HR change them, I suspect not, My friend and the one we owned were rated for 6000 lbs or so. We were close when loaded up. HR could have order the front different than Chevy standard. Our Ford is rated at 7000. I would think you have gotten there life out of them. Only you can decided what stiffness or firm ride you want. On my 7000 front axle I decided it was too soft, so air bags were install and that way very well worth it. On the P30 I just air up the bags to make thing better.

twodownzero

NM

Senior Member

Joined: 06/07/2014

View Profile


Offline
Posted: 04/23/19 03:55pm Link  |  Quote  |  Print  |  Notify Moderator

Springs are not rated for a certain amount of total weight. They are rated in pounds per inch of travel. It might be said that a pair of leaf springs can support "5000" pounds, but that doesn't mean one more pound would put them on the bumpstops or that would be useless. You do want to know the weight per spring corner so you have a ballpark of the proper spring rate, but spring capacity really doesn't tell you anything.

enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 04/23/19 04:07pm Link  |  Quote  |  Print  |  Notify Moderator

Did you have a dealer run your VIN number to see what front end you have?
GM made several different vehicle ratings with different weight front ends.


Bud
USAF Retired
Pace Arrow

2003 Chev Ice Road Tracker


olfarmer

Iowa

Senior Member

Joined: 03/29/2006

View Profile



Good Sam RV Club Member

Offline
Posted: 04/27/19 07:44pm Link  |  Quote  |  Print  |  Notify Moderator

All I can say is that I weighed the front end and bought the super steer springs rated for that weight. The motor home rides and drives better than it ever did. So far I am very satisfied and I got rid of those blasted air bags!


Ed & Ruby & the 2 cats
2001 Winnebago Brave 30W
7.4 gas Work Horse Chassis
99 Jeep Grand Cherokee


Racer-X-

North Georgia, USA

New Member

Joined: 04/28/2019

View Profile


Offline
Posted: 04/28/19 02:40pm Link  |  Quote  |  Print  |  Notify Moderator

I guess I'm late on this discussion. I just joined the forums here for other issues.

For future readers who might find this thread in a search or want more information, I thought I'd share some details.

Short answer, if OE springs are still available, like from GM or Ford or whoever, use your VIN to look up what was installed, and use a replacement for the original. That's the easiest solution. If you want to "do something different," then you should understand a bit more about how springs work and how y our suspension works.

Springs have two ratings that are important. One is the load capacity of the spring. This is how much weight can be put on the spring without damaging the spring (permanently deforming it or breaking it). For safety reasons, you need a spring that exceeds 1/2 of the GAWR for the axle that it's installed on. The reason for this is fairly obvious.

The other rating for the spring is the spring rate, expressed in "pounds per inch." This is how many pounds of weight must be applied to the spring to compress it one inch. The stiffer the spring, the higher this rate will be. Also note that for most suspension designs, the "wheel rate" in pounds per inch is different, often lower than the spring rate of the spring itself. This is because the suspension usually has leverage on the spring. For a dual wishbone type suspension, the wheel rate is the spring rate times the ratio of the distance from the spring center to the control arm pivot point to the distance from the lower ball joint to the control arm pivot point.

For a simpler explanation, if the center of the spring is half way between the control arm pivot (the bushings) and the lower ball joint, then the wheel rate will be half of the spring rate. That's because the wheel has 2:1 leverage on the spring.

enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 04/28/19 04:15pm Link  |  Quote  |  Print  |  Notify Moderator

Racer-x- that is good explanation of springs, however many P-30 chassis have airbags installed for more capacity. The airbags go bad. Small rockes get trapped between sprongs and airbags causing punctures. Replace with variable rate springs eliminate air bag requirements.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 

Open Roads Forum  >  Class A Motorhomes  >  Restoration & Vintage RVs

 > Another Question on Front Coil Springs
Search:   Advanced Search

Search only in Class A Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2020 CWI, Inc. © 2020 Good Sam Enterprises, LLC. All Rights Reserved.