Box Town Car Spring Options

[kishy]

"Harsh" is another concept I don't want anywhere near my cars lol.

An Air Lift kit (the bags inside the springs) is definitely an option. I feel like one could fairly easily use a stock controller, compressor and height sensor to just fill those as required. Some sort of purge solenoid would need to be used though. Maybe this is integral to the compressor unit on the pre-air-spring cars?

Though, I did talk to Air Lift, and their bags only expand outwards horizontally, not vertically. Therefore if the spring has already compressed from weight load, I feel like the Air Lift bags will be ineffective at lifting the car...just help resist it coming down any further.

[His Royal Ghostliness]

An Air Lift kit (the bags inside the springs) is definitely an option. I feel like one could fairly easily use a stock controller, compressor and height sensor to just fill those as required. Some sort of purge solenoid would need to be used though. Maybe this is integral to the compressor unit on the pre-air-spring cars?

The air-shock system cares not what's on the other end of the air line, as long as it's some sort of air containment vessel. So yes, you can switch the air shocks with air bellows of any type or size you can think of and it will still work just fine. Venting is handled thru the compressor. Basically the whole systems is under pressure all the time, unlike later cars where once the air springs are filled up their own solenoids close and the compressor vents itself and the air lines.

Though, I did talk to Air Lift, and their bags only expand outwards horizontally, not vertically. Therefore if the spring has already compressed from weight load, I feel like the Air Lift bags will be ineffective at lifting the car...just help resist it coming down any further.

If you're trying to fill up those bellows while they're in their free-standing position then yes, they will balloon outwards radially and not axially. However if they are constrained radially (by the coils of the coil spring), while axially they are placed is semi-compressed condition, then adding air to them will make them expand axially as well. Basically if the things are somewhat compressed with the car at ride height, they can lift the rear up when pressurized. Obviously the free-standing height of the bellows is very important here, which is why if you're to rob the bellows off a different vehicle application they may not work in a Panther even if they fit inside the rear springs.

[gadget73]

I say they suck because they don't hold up all that well. I've had both the Gabriel and the Monroe, and neither lasted more than a couple years. The Gabriels blew the oil seals out and fill the air bladder with shock juice. They also have some harshness from the small volume of air they hold. I'm currently running NOS late 80s vintage Motorcraft rear shocks, which are fantastic. Not the air type though, just your conventional type.

The bag in spring would have more volume. Not as much as the full on air springs, but more than the shocks. The stock 80s compressor system is under pressure all the time, and it vents through a solenoid on the compressor. Unfortunately since its under pressure all the time, and they never seal quite perfectly, you'll hear the pump run once in a while. Not a big deal, and if you have it set right it'll only do that when there is load in the back anyway. No reason you couldn't do this with a 90s type unit, and have it drive some sort of aftermarket solenoid. The 90s+ units vent through the compressor too, but they have a valve at each air spring that is closed unless the controller is commanding either a fill or a vent operation. Makes it much less prone to acting stupid unless the air spring itself is leaky. Honestly since the later stuff is easier to get hold of, I'd be seriously tempted to use that system just for available parts. If you really wanted to, you could probably figure a way to plumb it into an expansion tank too. Use an air pig for extra volume and you're golden.

[pantera77]

My 89 TC has factory air shocks that I replaced with the Monroe's, it doesn't ride harsh at all, and I normally despise Monroe shocks. Hell, I even put a stock replacement pair up front because the were on sale.
I'm sure they'll be dead in a year though.

[DerekTheGreat]

My '88 leaked at the T-fitting from the adaptor kit when I had my shocks switched over. Fixed that and it doesn't seem to leak at all. Once I get in as well as any passengers that's the only time I hear the compressor kick on. You can kinda feel it too. It's nerdy to fun to load the thing up and watch it raise and then suddenly remove all weight to watch it spring up and then come back down. I don't think it rides harsh at all. It's been a little over a year since I put the Monroe shocks on. Ashley did hers shortly after I did mine but there's either a problem with the sensor, brain box or relay. Haven't investigated it thoroughly yet.

[gadget73]

mine leaks at the connection at the top of the compressor. Not horribly, but enough to bubble soap. I've never had one of those compressor connections not leak at least a little bit. The Mark VII has 4 of them, all of them leak slightly even after replacing the O rings.

[kishy]

Though I do have an HPP Aero in my driveway to take things from, its air springs were gone before I got it, and I don't feel like making frame alterations. So I guess an actual air spring retrofit is out of reach.

Am I correct in thinking that air shocks alone, if used with existing sagging springs, will ride firmer/harsher because they have to be pumped up more?

And accordingly, if doing air shocks, it would be smart to replace the coils with new ones at the same time?

But, to avoid the expense of either of the above, air bags inside the existing coils could assist the ride height without having much of an effect on harshness?

I'm kinda leaning towards that last option. It would be nice to bump it up a little bit but keep it soft and floaty, and if the long term reliability on the air shocks is questionable, maybe I want to stay away from them...

[gadget73]

Yep. Making up for tired springs with air shocks is not exactly a smooth ride. Coils that carry most of the load so you can run as little air as possible will keep things riding like stock.

Same with the air bags inside the coils really. The more air they contain, the higher the spring rate so the harder the ride. They won't get as harsh as quickly though since there is more volume vs the air shocks.

[DerekTheGreat]

I like the idea of bags inside the coils, never thought there was a kit out there. I'll test the line coming out of the compressor someday. On the docket for tonight is vacuum leak detection/fix. Ashley's car also has a problem that may be voiced soon...

[kishy]

Returning back to the coil springs for a sec. Does anyone have a side profile pic of their car on 8805s (stock replacement) vs CC837 (Lincoln cargo coils)?

The free height on the CC837 is taller than the 8805s but of course the spring rate is higher. So I dunno. It's possible I may be able to accomplish my goals with coils alone.

It seems like regardless of what option I take, new coils should be a part of the plan. Then use an air option to supplement if it's not enough. But I also want to make sure it's not too much because bringing it back down again is not nearly as easy as pushing it up.

CC817 - Ford/Mercury Sedan Cargo Coils
Free Height: 15.94"
Installation Height: 11.63"
Load: 711 lbs
Spring Rate: 165 lbs/in

CC819 - Ford/Mercury Wagon Cargo Coils (not considering these, just included for comparison)
Free Height: 16.73"
Installation Height: 12.69"
Load: 780 lbs
Spring Rate: 200 lbs/in

CC837 - Lincoln Cargo Coils
Free Height: 16.38"
Installation Height: 12.13"
Load: 650 lbs
Spring Rate: 153 lbs/in

8805 - Lincoln Stock Replacement (constant rate)
Free Height: 17.19"
Installation Height: 12.13"
Load: 650 lbs
Spring Rate: 122 lbs/in

What does installation height represent? If it's the compressed height of the spring in an empty car, then apparently the Lincoln cargo coils "shouldn't" increase the unloaded height at all, just alter the way it responds to being loaded. I initially assumed it would have a lifting effect as the cargo coils do for the Ford/Mercury.

Weird anomaly - RockAuto lists the 8805 and CC837 as being for the Lincolns, but also the 91 (and only 91) Ford and Mercury, and for the older boxes, there is no Moog constant rate rear spring listed anymore.

[Kodachrome Wolf]

When I was looking for replacement rear coils on my '97, it listed those variable rate coils. I stupidly first tried wagon cargo coils on a Aero sedan, and I got a super lift job. I went back and ordered some constant rate Box springs for a 1980 Mercury Marquis. Gave me factory ride height with the near original spring rate.

The constant rate Lincoln ones you listed will be a touch softer than the cargo coils since they have a lower spring rate, but can still carry the same load since their load rate is the same as variable rate ones. I will say the Lincoln constant rate springs are a bit more supportive compared to the LTD/Marquis cars, since IIRC mine had a spring rate of 103 lbs/in versus 122 lbs/in yours list.

[kishy]

Ew, CC819s on an Aero?
I actually sold my CC819s (after being thoroughly dissatisfied with them in my '91 sedan) to a buddy with a 98-02, which was desperately sagging because of the 100s of pounds of tools he carries on a constant basis.

Even with that constant load in the car it's still really high in the back.

I'm finding quite the price disparity for spring prices here at home vs from across the border so RockAuto is going to be the vendor of choice.

Looks like Mevotech SMS8649 (seems to cross to Moog 8649) is the box Ford/Merc sedan constant rate spring. For whatever reason you can't find the Moog by looking up the vehicle, but if you search for it, you find it and then look at the applications list and see it'll work. So that's a RockAuto glitch. They're in stock and available. Of course that's not what I'm going for, it's probably the 8805 for me.

The reason why I don't want to just pull the trigger on the 8805s is because, according to the commercial I posted further up in the thread, stock ride height for a new 1984 is saggy in the back. Which is not what I want lol.

[Kodachrome Wolf]

I've got a set of the CC819s for the wagon. They originally were mine, I gave them to TecNickal for his stuff, and then he gave them back to me since the wagon's springs are shot out back. If they don't work well, I'll just order some constant rate ones (they're cheap).

As far as wagon cargo coils under an Aero went, I was looking for additional support, but really hadn't paid much attention to how much support the things would give:


I quickly switched it over to Moog 8649 constant rate coils for a '81 Marquis. For whatever reason, Aeros only have variable rate coils listed, so I went with Box ones since it's really not different back there by a whole lot.

[gadget73]

Don't have any pics of mine from ages ago on the Lincoln cargo coils, but I can tell you that after about 2 years I had 100 psi in the air shocks to maintain stock ride height. The soft part of the coils collapsed and it was saggier than the original 20 year old coils I removed because they were dragging ass. The stock replacement springs it has now have been in for probably at least 5 years without any obvious sag.

It is probably a little bit lower in the back than stock. I do have the thick spring insulators on the front which probably gives it about 3/8" extra beyond what the springs would normally. If you've got original front springs, the front will be lower than mine is with new anyway, so it'll likely sit about level.

[kishy]

Sounds like I'm doing 8805s with an Air Lift or equivalent kit for supplemental support if needed, then.

In the following pic, the only content of the car at all is:
-Gallon jug of antifreeze
-Quart engine oil
-Quart Dex/Merc
-Steel donut
-Belts, TFI module, voltage regulator, relays, fuses, screwdrivers...
(so in other words not much)

Top pic is 1/4 tank fuel, bottom pic is full until the pump clicked off twice. The sag is more significant on the passenger side so I'm thinking that particular coil spring is weaker than the driver side. If my tools (variable from 30-60lbs) were in the car it would be drooping noticeably more.



Note the tires are only 205s, they do squish down a bit. 35 PSI all around.