Air bag or not?

[rogers112869]

I have a '99 e350 4x4. I recently replaced all shocks with Bilstein 5100 and new coils. When driving over small dips etc, it feels like I am bottoming out or hitting the bump stop. Should I install a set of airbags in the coils to prevent that and have a bit smoother ride?

[mikracer]

Do you have a quigley? If you do, what did you replace your front springs with? If you replaced them with stock quigley springs then theres a good chance you're riding on the bump stops and you need a slightly taller spring, which is what Agile Offroad sells.

[rogers112869]

I replaced them with Moogs springs that were the same size as the ones that came on it from Quigley. I have about 3 inches of gap between the bumpstop and the axle.

[mikracer]

The issue is the lack of travel. The RIP kit sold by Agile includes a longer spring which gives it enough travel to stay off the bump stops. You could probably figure out what springs would be comparable to theirs if you dig deep enough. Lots of people are happy with that kit but it also includes custom valved shocks which help too.

[rogers112869]

Do you think going with a sumo spring in replacement of the bumpstop would help cushion that a bit? I am trying to avoid spending $$ at Agile after I just spent $600 for new Bilstein 5100s and MOOG CC81368 Front Coil Springs.

https://www.dsiautomotive.com/sumo-s...-van-front-4wd

[Twoxentrix]

They'll help...a little.
3" between axle and bump stop doesn't allow for much travel. If I'm doing my math correctly; Those Sumo's are just under 11" long and at 50% Compression they claim 1,000lb capacity (that's 5.5" of compression). Since you only have 3" travel, you cant even compress 50% so you'll still experience the jarring of the bump stops before you get the expected benefit of the Sumo's.

EDIT: Sorry, My assumption was you were not removing the original bump stops, and that the sumos you referenced were actually an air bag they made which fit inside you're coils. You would benefit from replacing your oem bump stops with the sumos you attached a link to.

[Steve C]

Just an observation with my van. I had a factory quigley set-up and never noticed the front end bottoming out on the bump stops as others have reported. My van is a 2001 with the 7.3 diesel and a HEAVY Ruenel bumper with 12,000 Warn winch. I was completely satisfied with the front end. However, I recently went with the full Agile RIP because I wanted to fix my van's saggy butt and just wanted a tried and true kit to update everything at once.

Not sure if the original front coil springs off my van were somehow stiffer than what your van came equipped with? I still have the springs and could send your way if interested. I'm sure shipping would be pricey and we'd have to wait awhile for the snow bank (6') to melt so they could be found...

In the meantime, I'm curious why you replaced your original springs and shocks. Was it because they too were bottoming out?

[rogers112869]

Hi Steve. The reason I switched was when I bought the van this summer, it had some old Rancho shocks and probably the springs Quiqley outfitted with. I contacted a guy here who reps for Bilstein and races their trucks and said both the shocks and springs were done for. Sloppy steering, etc. I have a steel bumper and warn winch. Today I measured and only have 1.37" of travel.
We went with the Moog CC-81368 Product Dimensions 15.06 x 11.12 x 5.12 inches
If your springs are a bit longer than i would be happy to cover ground shipping. I will say that the drive vastly improved with new shocks and springs. Its just when I am going over a speed bump, etc and it bottom outs that annoys me.

[rogers112869]

[IMG][/IMG]Update:


I measured and only have 1.37" of travel before the Quigley welded bracket.

[Kibo]

As you've already figured out, the lack of travel before bottoming out is the fundamental issue. The common solution is to increase the travel, but that introduces a number of other considerations (shock travel, increased ride height, front end higher than rear, alignment/caster concerns, need for a drop bracket on front swaybar, etc.). You could look at using a different bump stop solution that is more progressive in nature, or stiffer (higher spring rate) springs at the same free height, but increasing the travel is really the best solution.

The springs you've chosen are relatively short at 15.06" free height. A common spring upgrade for this problem is the Moog CC880S, which has a free height of 16.60". Naturally, this results in your van sitting higher (assuming comparable spring rates) and provides additional travel:



Ideally you'd want to know the weight on your front axle. Since your front springs are new with a known free height and spring rate, you can measure the length of your springs with your van on level ground and calculate the weight of your van. With this information, you could then calculate the expected ride height using other springs such as the CC880S and determine the best springs for your setup. It gets a bit more complicated with progressive springs like the CC880S, but it should allow you to make a pretty good estimate of how much clearance/travel you'll end up with.

Steve's springs may very well achieve the desired result; but without knowing the free height (which can be measured) and spring rate (more difficult to measure), the only real way to know would be to install them. It may be that the additional weight of Steve's setup was compensated by a higher spring rate, which could result in a stiffer ride at the same travel/clearance. This would keep you off the bumpstops, but you may be not be happy with the resultant ride quality.