Mustand II front coil springs

rick 36dodge · November 08, 2004, 05:48:35 PM

About a year ago I put a Mustang II front end under my 1936 Dodge Coupe.
It has a 350/350 with air. I have a Walker Corbra Radiator. The crossmember is from Fat Man. I put a pair of TRW CS 8558 front springs.
These are supposted to be from a V-6 Mustang II. This is what was recomened from Fat Man, not the spring number but the V-6 Mustang II.
It started out a little high, but settled about an inch in the first month. Now it has settled anouther 1 1/2''. It is ok as long as I don't hit a bump in a turn then my tire scrubs the fender.
Do any of you have any suggestion as what front springs will work (about 1 1/2" higher ride hight) ? Are these springs too light ? I think the spring rate is 352#. Any suggestions would be appreciated, also give stock number and spring rate.
Thanks, Rick Harris

phat46 · November 08, 2004, 06:07:29 PM

That seems kinda odd. The first inch of settling seems normal, another inch and a half seems like a lot. My '46 Chevy has 300 # springs in the front with a stock Must II suspension. It sits low, but that's because of the way i mounted the crossmember. I have aftermarket springs that are 1" shorter than stock, it rides rather "firmly".
It seems that 2 1/2" of settling is too much, I wonder if there's a way to see if the springs have lost some tempering? Many guys use the four Cyl. springs and find them just right.

58 Yeoman · November 08, 2004, 07:31:07 PM

Are you sure the springs weren't mis-numbered? It's getting to be common to buy something that has the wrong numbers on it. I've seen in the Heidts catalog where you would use the 4 cyl. springs for a V8, also.

river1 · November 09, 2004, 12:59:38 AM

you might try eaton

http://www.eatonsprings.com/m2coils.htm

later jim

rick 36dodge · November 09, 2004, 09:54:48 AM

Quote from: "river1"you might try eaton

http://www.eatonsprings.com/m2coils.htm

later jim

Thanks for the link to Eaton springs, very helpful.
Thanks, Rick Harris.

purplepickup · November 09, 2004, 11:18:04 AM

While we're on the subject, I think I'm going to have to change the springs on the Mustang II front end under the Rambler wagon. The ride height is real good but the ride is too firm. My question is, can I tell what the current spring rate is by the number of coils, wire diameter, and length? ....or are there other factors that determine spring rate too?

I need to find out where I'm at before I can pick a set of springs that will improve the ride but not change the ride height.

moondisc · November 09, 2004, 11:59:41 AM

Every car is different. Unless you compare exact same vehicles, engines, accessories, crossmembers, A arm length, wheel offset etc etc etc, what works for one may not work for another.
Having said that, I have a set of 350# Chassis Engineering MII springs. CE springs are the same length as stock MII springs with 1 1/2 coils cut.
I put these in the 41, but with the long bottom A arm I needed much stiffer springs, so they never left the garage.
Cost me $60 6 years ago, I'll take $30 for them.

enjenjo · November 09, 2004, 01:32:32 PM

Quote from: "purplepickup"While we're on the subject, I think I'm going to have to change the springs on the Mustang II front end under the Rambler wagon. The ride height is real good but the ride is too firm. My question is, can I tell what the current spring rate is by the number of coils, wire diameter, and length? ....or are there other factors that determine spring rate too?

I need to find out where I'm at before I can pick a set of springs that will improve the ride but not change the ride height.

Spring rate depends on wire diameter and length, rather than loaded height, and unloaded height is not relevant. Two springs with the same loaded height can have different unloaded heights. The other thing that enters in to this, many people, including me, cut the springs, so the rate changes. I have also found that the amount springs rust in use will change the rate, and sand or bead blasting the springs changes it too.

I have found that the 4 cyl springs are only useable in cars like a 34 Ford or similar where the engine is completely behind the center of the axle. As cars get newer, the engine moves forward, so for 35 to 40 cars, I start with V6 springs. on later cars, and some of the earlier ones with the engine centered over the axle, I use V8 springs.

In many cases, I cut 1/2 to 1 coil to adjust ride height, it doesnt seem to affect spring rate too much doing this. However cutting more than that is noticeable. If the ride is ok, but the ride height is too low, I use spring spacers to raise it up. There are some 1/2" rubber spacers out there that work good, if I have to go more than that, I make a metal spacer, with a guide to hold the spring in place. Progressive has a crossmember with an adjustable top spring mount, great idea.

So the first thing to do, is figure out if the spring has been cut. If it has, a slightly smaller wire, without being cut, may be what you need. If you get the ride the way you want it, but the ride height is off, if it is a small amount, you can use a spacer or cut a portion of a coil. One full coil is generally about 1 to 1 1/2", depending on how tight the coils are wound.

The confusing thing is replacement springs may not look like original springs, even with the same advertised rate and application, because there is more than one way to skin a cat. A coil spring is a Torsion bar bent into a circle, and works by twisting the wire. cutting the spring changes the length of the torsion bar, a shorter bar is stiffer. So many coils of large wire can give the same rate as fewer coils of smaller wire. But generally, the bigger the wire, the higher the rate, the more coils, the lower the rate. So a 10 coil spring will have a lower rate than an 8 coil spring, at the same ride height, as long as the wire is the same size. But if you cut the 10 coil spring to 8 coils, the rate, and the ride height will both change.

If you go to Eaton for springs, they will need the front end weight of the car, and the desired loaded height of the spring to make the ones right for your car. Also an idea of the desired ride quality.

Nothing is simple is it

A rule of thumb is soft springs, control ride with shocks, and roll with a sway bar.

Pope Downunder · November 09, 2004, 08:55:31 PM

Quote from: "purplepickup"While we're on the subject, I think I'm going to have to change the springs on the Mustang II front end under the Rambler wagon. The ride height is real good but the ride is too firm. My question is, can I tell what the current spring rate is by the number of coils, wire diameter, and length? ....or are there other factors that determine spring rate too?

I need to find out where I'm at before I can pick a set of springs that will improve the ride but not change the ride height.

Here is a site that might help with the calc.;
http://www.miracerros.com/mustang/springs_calcs.htm

On Rick's problem, from his description, I'd say his springs are yielding, indicating they are being stressed too highly. Possibly a problem with the tempering?

purplepickup · November 09, 2004, 11:26:27 PM

Frank and Neil, thanks for the info. I saved it for future use. I haven't got the Rambler on the hoist yet, but after I do some shop cleaning and rearranging I'll start checking out what it needs.

Dirk35 · November 10, 2004, 08:43:49 AM

Quote from: "moondisc"Every car is different. Unless you compare exact same vehicles, engines, accessories, crossmembers, A arm length, wheel offset etc etc etc, what works for one may not work for another.
Having said that, I have a set of 350# Chassis Engineering MII springs. CE springs are the same length as stock MII springs with 1 1/2 coils cut.
I put these in the 41, but with the long bottom A arm I needed much stiffer springs, so they never left the garage.
Cost me $60 6 years ago, I'll take $30 for them.

Moondisc, Id like to buy those springs from you. For $30, even if they dont work, I cannot go wrong.

My e-mail should be in my profile.

rick 36dodge · November 10, 2004, 07:34:22 PM

I want to thank you all who have given me advice. I still don't know how to fix my problem. I went back to the parts store where I got my springs, and they let me look at the TRW book again. I only have a 2 year degree in Mechanical Engineering. It seems the more I look in the TRW book the more confused I become. The spring I have now is a TRW CS 8558 it is for a 1978 Mustang II V-6 w/ air. It has a spring rate of 352# , free height of 13 7/16" , loaded height of 9.50" load rating 1388 lbs. I looked up the same year V-8 Spring w/air and it is CS 8582. This is where I get confused. It has a spring rate of 317# , free height of 13.94" loaded height of 9.50" load rating of 1400 lbs. It seems to me that this spring would be a higher pound rating to hold more weight. I don't know the coils per inch , but the wire dia. is the same at .580".
These CS 8558 is eq. to Eaton part no M24046 and the CS8582 is the same as the M25652. The next higher rated spring is Eaton M21122 rated at 367# at 13.750" free height. The ride is fine just tooo low.
Should I get this spring to raise the ride height 1" to 1 1/2" ? Or any other suggestions.
Thanks for your help, Rick Harris.

enjenjo · November 10, 2004, 08:14:50 PM

Pull the spring, install a one inch spacer on top of it, and put it back in. The ride should be the same, just an inch higher.

tomslik · November 10, 2004, 08:59:03 PM

Quote from: "enjenjo"Pull the spring, install a one inch spacer on top of it, and put it back in. The ride should be the same, just an inch higher.

yep, i second that.
had to do it with the EXACT same springs,heaviest i could find with the correct dimensions.

rick 36dodge · November 10, 2004, 11:04:50 PM

Quote from: "tomslik"
Quote from: "enjenjo"Pull the spring, install a one inch spacer on top of it, and put it back in. The ride should be the same, just an inch higher.

yep, i second that.
had to do it with the EXACT same springs,heaviest i could find with the correct dimensions.

Thanks a bunch guys !
Rick Harris