: Suspension LIft

01-30-06, 02:29 AM
I have a 90 Fleetwood Bro. and I wanted to know what would be the best suspension to go with to raise it up in the back??

01-30-06, 10:33 AM
Depends on what you are seeking:

1. Ride/Comfort, same ride as now, just higher
2. Stiffer, aka for towing or carrying heavy loads.

Air Shocks were common, if not standard on most Cadillacs for years. They do well for most Cadillac needs, keeping comfort and ride same, but car always level.

You can go with taller springs (Station Wagon springs) that will likely be stiffer than stock, and will raise it up some.

But you really need to know what you want, how tall, how stiff, and what impact that will be to the rest of the car's handling (aka, stiff springs in back might induce more oversteer in a hard corner, causing an potential accident tot he unaware driver)

If you are looking for towing, additional weight capacity, look to the FE2 springs, they are stiffer and w/the load leveling shocks, they are capable of 840 lbs tonque weight (on a 94-96 FW/FWB). Properly setup car of course.

01-30-06, 11:03 AM
One of my favorites is to use "progressive" springs known in many circles as "load-levelers". I've used these types of springs many many times and have always had great success with them. Generally speaking, I've found that they have several pluses:
1. They correct for sagging OEM springs.
2. They provide a BETTER ride than OEM springs.
3. They increase your load carrying capabilities and in many cases can REPLACE the need for the OEM rear air shocks.

I have used these springs on many customer cars over the years as an alternative to replacing the costly ELC components on Cadillacs. When ordering, I generally use the stock application as a guide. Only on limousines have I had to upgrade to stronger springs.
Even if you wish to retain your original equipment ELC system, these springs will make it so only the largest of loads would ever cause the system to activate.

01-30-06, 11:09 AM
How far down do to the progressives go before they start to stiffen up? 1in? 4in? Just curious. I have personally been hesitant on them due to the variable rate nature.

Or is each supplier unqiue?

01-30-06, 11:37 AM
I would assume that each is unique but the ones we used were Moog and to be honest I never really tested them to any great degree other than road testing with a variety of loads added to the rear seat and trunk. They always improved the ride quality and until we were approaching what I would call over-load condition, they seldom caused the ELC to activate.

01-30-06, 12:25 PM
My springs are stock FE2's (I am guessing if front spring RATE is same as Impala SS FE4, just taller) the rears should be very close if not same as Impala SS (again, only taller). Do you agree? I have heard people complain the Impala SS springs are too stiff on a FWB. I can't imagine they really are, not to me at least.

I would not mind a little stiffer in back. We will likely tow some this year, only 60 miles or so, but likely 5000-6000#'s when we move. We will just load UHaul 6x12's to keep costs down and move it in shifts with the Suburban and the Cad. As mine can technically handle more weight, I will likely tow the heavier stuff. The Suburban might get air bags soon, as the rear springs are getting weak now and sagging more and more. Air bags appear to be cheaper than new springs and a heck of a lot easier to install.

But if I get the air bags in the Burb, and it has the 9.5" SF 14 bolt axle, it probably is the better vehicle to tow heavy with. But the Cad has bigger front brakes, the truck has bigger rear....

01-30-06, 12:43 PM
As I recall (we used to be a U-Haul dealer) the 6x12's are dual axle trailers so they don't put TOO aweful much tonque weight on the tow vehicle. The big issue will be the mass in starting and stopping.
As for the springs, I remember going through spring books looking at a number of different springs and as I recall, there's more possibilities for the Impala SS than you might think. I'm pretty sure there's at least a couple different choices and therefore when you drive an SS, ride quality could be hard to duplicate without knowing specifically which springs the car had, and to lesser degree what condition they were in relation to new.
I know that for this reason, when I was re-springing my Fleetwood, it took several tests before I nailed a combination that I liked. I was fortunate to have a friend with a shop that allowed me the lattitude to test the springs to my liking. I had to not only find ones that made tha car sit the way I wanted but give me the ride quality I wanted as well. Believe me, I was more than happy to get that over with. If you get ahold of a spring book, you can look up the ones that came on virtually any car and then pick out a set that will be taller, shorter, firmer, softer based on the specs alone. Unfortunately, in the end it WILL still come down to the test drive. Also remember that the springs will generally settle slightly a short time after installation so you need to allow for that.

01-30-06, 01:16 PM
I seem to remember my friend who had a new SS swapping in new springs due to large amount of stereo equipment. Odd, GM was HELPFUL in it! They sent him a list of springs and weights and ride heights that were from the B/D chassis. I don't know if he has the list still or if GM has anyone that could get that info. I know how my company is now, if I had someone ask me for info on an old program, if I personally worked on it, I might have access and know where it is, else, it would be archived somewhere, likey in a box off site where it will be long forgotten and eventually disposed of....

Or stored on a HD somewhere and eventually people lose access to it and forget it exists....

Like the old cell phones I did. I can get enough to BUILD them again, but not necessarily why we did what we did in the design, that much is hard to keep track of. And memory isn't that great after 10 years...

01-30-06, 01:27 PM
I just checked with Moog and they are actually quite helpful. You can look up the springs numbers by application online but have to call and get the actual specs of the springs. According to their website:

'95 Fleetwood
Front - #5396 load=2108, Rate=393
Rear - #CC621 (variable rate) Load=640, Rate=175
(Odd they only show one set available for this application.)

'95 Impala SS
Front - (STD) 5044 Load=2360, Rate=345
Front - (HD) 5030 Load=2899, Rate=435

Rear - (STD) 5245 Load=1059, Rate=122
Rear - (HD) 5419 Load=1211, Rate=170
Rear (variable rate) CC621 Load=640, Rate=175
(Interesting that they spec the same rear variable rate for both these cars)
With respect to these numbers:
The Load number is what's required to get the car to the factory trim height
The Rate number is what's required to compress 1" from the factory trim height.

01-30-06, 02:43 PM
So careful weighing (4 wheel) is important when spring selecting. Unless you can R&R each spring to see what "floats your boat" (pun intended...)

Can you weight each wheel on a truck scale and get accurate readings? I have one litterly about 500 feet from the house (farm grain mill) that charges like $3 to weigh you.

I know I did front/back on a scale, as my 76 Delta 88 wheelbase was too long to weigh the whole car some years ago at a warehouse scale (free, guard at gate was happy to have something to do at night....) So I got a ticket showing front and back separately. It was nearly 50/50. Full tank of gas (26 gallons) in a 76 Delta. 4860 lbs.

01-31-06, 08:33 AM
Not sure how accurate that will be. When I worked at the limousine coachbuilder, we used a 4-scale electronic system that gave us individual weights at each wheel.