Add spring spacers or get heavier springs (1 Viewer)

[kcjaz]

So when my BP-51 suspension was installed, the installer just left the factory set preload on the front struts. I have a TJM T13 w/o a winch and the preload should have been reduced.

For the rear I have OME 2721s. The result is a level truck with no cargo weight in the back. Add a a few hundred pounds cargo and the rear sags a little.

I know I can just adjust the front strut preload and then redo the alignment to reduce the front lift and get back a little rake to offset the rear sag when loaded. The thing is that I like the height of the front.

Sooo, what I want to do is increase the rear lift. I like the ride I have now with the 2721s so I could just go with spacers. I’d like to get an additional 1” but 1/2” might be enough. Or I could just get difference rear springs.

I would thindifferent springs would be “better” but it will cost more and I don’t want the ride to be too stiff.

Opinions?

Here’s a pic of my rig with no load in the back.

An 1” higher in the rear would be about perfect.

 

[TeCKis300]

Nothing wrong with using spacers to dial in ride height. Functionally, it's pretty similar to adjusting the perch on a coilover. Just done differently. Sure, if you're an elitist and can find exactly the right spring that has the unladen height and spring rate, go for it. Installation is just about the same too.

There's tons of spring spacers out there - 5, 10, 20, 30mm. Sounds like 20mm (~.75") will suit you nicely.

 

[linuxgod]

If you like the 2721 performance unloaded as well as under normal load, just install rear spacers/"trim packers". Unless you find a similar spring that is slightly taller, you're most likely to end up with a spring that's too stiff and makes your ride less pleasant when unloaded.

 

[kcjaz]

If you like the 2721 performance unloaded as well as under normal load, just install rear spacers/"trim packers". Unless you find a similar spring that is slightly taller, you're most likely to end up with a spring that's too stiff and makes your ride less pleasant when unloaded.

That was my thought too but wanted to seek feedback from The Crowd.

 

[tominboise]

I have spacers on the back of mine and have had for two trips to Moab and all the other driving I do. Everything works fine.

 

[linuxgod]

That was my thought too but wanted to seek feedback from The Crowd.

FWIW I tow a lot and I appreciate heavier springs over stock for that. But mine are 240#/in (vs 170#/in for factory). The 2721s are progressive coils going from 270#/in to 340#/in. If I was buying new coils now I'd go with the 2721's. So you're already about 10% stiffer than I am when unladen. I imagine to get the height you want you'd need to go to 340#/in or higher coils, which you'll definitely feed when unloaded. That said if you're planning drawers and/or a rear bumper then maybe go heavier and live with the stiffness until then. Otherwise I'd opt for trim packers as they are cheap and easy

 

[kcjaz]

Update:

I did a little test by adding weight in 100lb increments to the back and generated the following data for the 2721 springs installed in my 200:

lbs deflection
0 0
100 1/4"
200 1/4"
300 1/2"
400 5/8"
500 3/4"

The 2721's are 270#/in-340#/in spring rate. The data above tells me that the 500 lbs of cargo resulted in an effective spring rate of 500/2/.75= 333#/in. It seems most of the lighter spring rate is used up with just the empty truck weight. The 2722's are a flat 275 #/in spring rate so 500 lbs of cargo would squat the back even more the 3/4". It would be about 0.9". However, the free length of the 2722s is longer than the 2721s (440 mm vs 410 mm). So I believe the 2722s would result in a little more unloaded lift than the 2721s but its hard to know how much and when loaded with 500 lbs, I'd probably end up in the same place I'm at now with 2721s and no spacers. So, I agree with @linuxgod that I'd probably need 340#/in springs to get the loaded height I'm after but that would affect the unloaded ride which is most of the time as this is my daily driver.

All of this convinces me spacers are the right answer for my application just as you all told me above (just needed to work it out myself - maybe I have trust issues). A 20 mm spacer would cover the 500 lbs. I called Slee and all he has for my 2013 200 are 15mm spacers. Where can I find 20 mm or maybe even 25 mm spacers? Don't they need to be specific for the 200 and the springs I'm using?

 

[Taco2Cruiser]

If you like the 2721 ride, then stay with that.

I’ve had them all under my truck, and I love the 2723 with no load, no rear bumper, no fuel. I just did a ‘18 with the same setup, and it just floats so smooth down the highway. Or ask @JohnB who has driven my 200.

BUT... it rides high, it’s definitely going to have its back side up in the air. Which if you’re like me, you want, because you always have either a bunch off camping gear and a family in it or are towing. So I need the height for off roading and not having a saggin’ wagon.

For you, I don’t see you happy on the jump up to a 2723. You’ll probably be much happier on a 10-20 mm trim packer.

Where 2721s are better than 2723s when unloaded is for more city drivers that don’t wheel much or have regular heavy loads. Because pot holes, speed bumps, and slow city driving gets old. A soft spring is much more appropriate. I live where we have smooth, winding mountain roads. If I drive in Chicago like @linuxgod, I’d stay away from 2723s and run 2721s. 2722s fell almost the same but hold a couple hundred pound better due to the .5mm thicker bar diameter over 2721s. But i don’t feel like it’s the best spring and prefer to avoid it.

Or you can play around. Rear springs are cheap, like Less than $200, and if can swap them out yourself, then too easy.

2720s for city drivers that take their rear seats out.
2721s for guys that want a lift without the harsh ride.
2722s for maybe the LRA 13 gallon guys. Maybe, but really stick with the 2721.
2723 for the off roaders, campers, or heavy rear bar guys. But not a combination of all three, maybe just two of them.
2724s for the rear bar, drawers, LRA 24/40, RTT “What else can I buy” guys. Not making fun, I fell in that world. I just made to back to tell the story.
2725 for armored trucks. As in rifle and tiny explosive blast protection. Don’t buy this spring if you don’t have that. All the recreational bumpers, tents, fuel, drawers, and fridges don’t keep enough weight to handle them. Maybe when absolutely full on all supplies, but when that LRA gets low on fuel, it’s too brutal if a ride.

 

[kcjaz]

Great summary of the spring options! Thanks @Taco2Cruiser.

Where can I get a 20mm or 25 mm trim pack?

 

[terdrocket]

Great summary of the spring options! Thanks @Taco2Cruiser.

Where can I get a 20mm or 25 mm trim pack?

Trail Tailor has the 30MM in stock. Trail Tailor

 

[CharlieS]

One thing I'd add @Taco2Cruiser - and you may have a different experience - the progressive part of the 2721 helps eat up dirt road washboards. I see a lot up here, very few dirt roads here are smooth.

 

[Taco2Cruiser]

One thing I'd add @Taco2Cruiser - and you may have a different experience - the progressive part of the 2721 helps eat up dirt road washboards. I see a lot up here, very few dirt roads here are smooth.

From my time living in the desert, I don’t feel progressive springs are the perfect answer. I like a Constant Spring rate with a secondary bump stop.

Progressive springs tend to kick back a little faster when you go into that area of the spring. I like progressive for smoother driving conditions, where temporary weight is a factory.

 

[linuxgod]

From my time living in the desert, I don’t feel progressive springs are the perfect answer. I like a Constant Spring rate with a secondary bump stop.

Progressive springs tend to kick back a little faster when you go into that area of the spring. I like progressive for smoother driving conditions, where temporary weight is a factory.

The next time I have to pull my rear springs I plan to go to 2721s. The coil rate is similar to the Tough Dog standard duty springs, which I'm reasonably pleased with, especially with 200-250# of stuff in the rear (either gear or kid+dog+toolbag). Where I'd like more support is when towing as the TW on my trailer is about 850#... or as much as 920# shown below with 3 weeks of clothing etc in the trailer, and when I'm loaded my rear axle weight is HEAVY. First weight is pretty typical weekend trip. Second was with the waste tank full coming back from the west coast last year. Edit - third weight is the same setup as the second but the trailer is unhitched. So 3 kids (2 middle row, one in the 3rd row), half-empty cooler in the trunk, tool bag, trailer hitch (ball, head, and drop shank), and some misc other stuff in the vehicle. Remove the cooler, trailer hitch, and some misc stuff and I probably sit right around GVWR with the normal family of 5 if not maybe a few pounds over.