replacing springs on wagon for 1000#+ cargo capacity?

[BerniniCaCO3]

Bought my colony park wagon about 6mo ago, to use as a hauling/commuter vehicle: better fuel economy than a pickup, and to some extent better taken care of, but still with loads of cargo space.
It's a 1990, fwiw

In short... I think I'm damaging the springs with the cargo I'm using it for, as they seem to now bottom out (only on speed bumps and coming out of the driveway, which is on a slope-- not on the highway, not yet) ever more frequently, one what feels like lighter loads than it used to take. It was starting to bottom out last weekend under only 600-800# of tools and 3 smallish boxes. Then later this week, I put in just the empty boxes, and it started to bottom out again! They weren't more than 250#, I'm sure of it? I don't do this every week and weekend, but often enough that it's going to get to be a problem. I need to carry 400# this coming weekend.

Can I get new springs in the rear rated for, if the rest of the car can handle it (these were used to tow trailers, so I think the engine/transmission should be cool with it?), say 1000#?

And if so --I've never done suspension work beyond shocks-- how do I know whether a given set of springs will fit, how expensive are they to buy new and where would you get then (autozone? ebay? OEM but online--stealership will always be too expensive)? Or, if they don't wear out, not really, I might go used at the junkyard. Just for perspective, I refuse to pay $40 for a 2nd hand radiator that has even MORE miles, hasn't been maintained at all, that I have to messily remove and drive 30 miles to the nearest junkyard for... when new with warranty is $100. Especially since that's an item that does wear out, clog up, start to leak.
If springs last forever, and if it's $150 new or something insanely expensive and only $30 used, then I'll go to the junkyard What's your advice/experience?


thanks!!!
-Bernard

[GoodSamaritan]

There are quite a few spring options out there, and they are easy to change.
I didn't even have to completely remove my shocks. I just undid the nut that held them to the differential at the bottom, and flexed them just enough to get them off the stud.

Now you can lift and secure the car by the frame, and the differential is free to pivot downward, freeing the springs. I had to take a 2x4 and pry down on mine a bit, as the byshings for something in the rear suspension tended to keep it up tight against the spring. Be careful not to crush, or otherwise damage a brake/fuel/whatever line.

Also while you are under there, it would be a good time to put on a set of air shocks, or some of the ones with a coil spring around the outside of them, that will also increase the load capacity.

Springs have been discussed here quite a bit, there should be plenty of threads to dig through if you do a search. Failing that, you can get a set of stock cargo coils through autozone, or other auto parts stores.

Front springs, also get saggy on these cars, but are a bit more involved to change. It does make for a better handling ride though.

Welcome to GMN.

[87gtVIC]

I have a pair of wagon cargo coils you are welcome to have for cheap after I remove them from my coupe.

I think the suggestion of coil overs is a good idea to help the load.

[1990LTD]

To find out whether or not other springs will fit check the measurements against the ones here

http://www.grandmarq.net/vb/showpost.php?p=158894&postcount=7

[gadget73]

Do you always have that much weight in the car, or is it a sometimes thing? If you don't always carry that much weight, what you may want to look into is a set of air booster springs Basically its an air spring that sits inside the coil spring to add more weight capacity as needed, but when not required you can simply bleed the air down to restore normal ride height and characteristics. Air shocks are also an option, but I don't believe they handle as much weight as the springs do.

Cargo coils in my experience don't last very long. Maybe the wagon ones work better, but on the sedans, they're shot in about a year. You may be better off with new replacement springs, either in stock rate or a higher rate. Coils do wear out, and the stock ones are only like 80 bucks a pair, so its not really worth sticking used ones in.

[BerniniCaCO3]

87gtVIC, when do you think you'll remove them, and what price did you want?
Newish and non-saggy?

Just ordered the cc819s off amazon late this morning before I saw your reply: probably not too late to cancel. They were $70.50 shipped, decent deal I thought.

Front just has always the same load: myself and the engine, and yes, the engine is the greater of the two. It doesn't seem to sag, though, I also don't know what stock ride height was either! Anyone know? Springs are probably 20yr old original, so I don't actually know what a comfortable ride would have been. Is it probably just time to do them anyway?
Maybe I should also replace the front springs with variable load, if available?

These look like the rear shocks you would go with?

http://www.amazon.com/Monroe-58568-Sensa-Trac-Adjusting-Absorber/dp/B000C53RQ2/ref=au_pf_ss_7?ie=UTF8&Model=Grand%20Marquis|718&n=15684181&s=automotive&Make=Mercury|56&Year=1990|1990&carId=003

If I do rear AND front shocks AND springs, that will be overbudget. Thinking I'll just do the rear, would new front springs or shocks really do anything for me, when all the weight is going to be behind the front seats anyway?

[BerniniCaCO3]

oh, and thanks for the link btw! Very handy; didn't come up in a search for "springs heavy," but then, I didn't really know what I was searching for!

[87gtVIC]

They were installed on the car in June of 2007 so they are a couple of years old. They are in my two door so I would assume that are not clapped out as of yet You can check out pictures of the cars ride height in my readers ride thread. I have a lot showing the stance of the car. I would only want 20bucks plus processing/handling/shipping. I personally feel as if they never settled down since the install so it is your call. I don't carry any weight in my car, so they may be different on a wagon with weight loaded on them.

[1987cp]

MaxAirs aren't an awful thing to do, and they're cheap and supposedly add 1000 pounds to your payload capacity. Ride decently, too, though possibly not the best for handling.

My preferred option for the future would be to get load-helper airbags that install inside the coil springs. But there's some debate on which of these would actually fit, and selection seems to be pretty limited SFAIK.

[GM_Guy]

The wagon coils are about the only off-the-shelf spring out there that will fit (diameter and height). I poured over the spring catalog looking for something beefier, but the wagon coils where it. There where a couple beefier springs that fit the space, but where too short to be practical (one such spring was for a 1976 ford car model I forget the name of, it would have dropped the rear around 3", 2" shorter to begin with, add the weight of the car and you easily lose another inch).

Alex.

[zoomie]

im putting limo springs in mine soon, ill let you know how they turn out.

[mitymerc]

Air bags work well.....

[BerniniCaCO3]

Do you have the part number on the limo springs, or, were they salvaged?

The only reason I'm resisting air bags, is the fact that I rarely have a compressor handy, and it'll be impractical for me to stop home whenever I know I'm picking up a heavy load, because I won't necessarily know...

[zoomie]

Do you have the part number on the limo springs, or, were they salvaged?

The only reason I'm resisting air bags, is the fact that I rarely have a compressor handy, and it'll be impractical for me to stop home whenever I know I'm picking up a heavy load, because I won't necessarily know...

gotem at a junkyard 25 bucks from a box limo

[gadget73]

comprimise solution: air bags and install a small onboard air compressor. You can find one on any 90s Towncar and do a little plumbing magic to have it end up with an air chuck. Theres a neat system found in the back of some 90s Buicks that has a hose reel with a tire chuck plumbed into an onboard air compressor as well.