Why do our truck suffer from S.A.S?

StreetCreeper

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I'm curious as to why our trucks suffer from Saggy Ass Syndrome so much more than other vehicles? I understand spring fatigue, but why is this seemingly more prevalent with 3rd gen 4runners than with other other similar vehicles?

I understand there was a recall on the bump-stops, and the extended ones were put in to limit spring compression, but that obviously doesn't address the actual spring issue.

Is it just a matter of most trucks having leaf springs in the rear instead of coils? Or is it just a design flaw with springs....or a design compromise when using coils in the rear of any vehicle that has more than normal suspension travel?

I rarely see other vehicles driving down the road with saggy rears, but when I do, it's an obviously over-loaded vehicle....or an empty 2nd or 3rd gen 4Runner.
 
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I don't know either. But when I had my stock springs and i had 3 or more people in the back of my 4runner it looked like I was popping a wheely. Now with my heavy duty OME springs I have had 6 people in the back (8 in total) and I still have less sag than stock. Stock springs are just flimsy I suppose.
 
I'm curious as to why our trucks suffer from Saggy Ass Syndrome so much more than other vehicles? I understand spring fatigue, but why is this seemingly more prevalent with 3rd gen 4runners than with other other similar vehicles?

I understand there was a recall on the bump-stops, and the extended ones were put in to limit spring compression, but that obviously doesn't address the actual spring issue.

Is it just a matter of most trucks having leaf springs in the rear instead of coils? Or is it just a design flaw with springs....or a design compromise when using coils in the rear of any vehicle that has more than normal suspension travel?

I rarely see other vehicles driving down the road with saggy rears, but when I do, it's an obviously over-loaded vehicle....or an empty 2nd or 3rd gen 4Runner.

Look at some of the newer SUV's and trucks. They all have a rake to them. Anywhere from 1-2".

The 4th and 5th gen's sit almost 2" higher in the rear. When they lift there trucks they do a 3" front and usually a 2" rear coil setup.

This added coil in the rear allows them to sag after miles and not look like out 3rd gens did. Worst case after time they will slowly level out.
 
Look at some of the newer SUV's and trucks. They all have a rake to them. Anywhere from 1-2".

The 4th and 5th gen's sit almost 2" higher in the rear. When they lift there trucks they do a 3" front and usually a 2" rear coil setup.

This added coil in the rear allows them to sag after miles and not look like out 3rd gens did. Worst case after time they will slowly level out.

So we complain about saggy asses and meanwhile, the 4th and 5th gen guys always talk about lifting to get rid of the terrible factory rake. Clearly there is no winning…

1.5-2" of rake is ideal IMO
 
It gives us a reason and probable cause to build our truck. It is much easier this way to justify the cost to fix the " Factory Problem" and upgrade them to our wife's.....

Blue
 
So we complain about saggy asses and meanwhile, the 4th and 5th gen guys always talk about lifting to get rid of the terrible factory rake. Clearly there is no winning…

1.5-2" of rake is ideal IMO

Thats great!! My brother went with the Metal 4x4 with extended flex rear. He hopes it has a little rake but from what I can tell it will be level.

Funny side note. Every 5th gen lifted I see around town has a major lean. Everyone of them. Its bad, wife always notices it when we are behind one.
 
My best guess is that it's hard find find a spring that's heavy duty enough and will last a long time, when trying at the same time to give a nice factory smooth ride. I think this has a lot to do with how relatively light weight 4Runners are (when compared to other SUV's of similar size). Most people are expecting a car like ride in a SUV like a 4Runner, yet 4Runners are also expected to do some heavy lifting, maybe up to 1000 lbs + (of people + cargo, and also trailer tongue weight). That's 1/4 of the weight of the truck. It's not easy to engineer something to have a car like ride, AND be able to hold/tow a considerable amount of weight, while overall keeping the truck light weight. It's hard to get a set up that works for everything, that looks the way you want it to at the same time.

Edit: basically my opinion is that trucks that are designed to haul heavy loads, are also generally much heavier themselves, so the weight they are hauling is a smaller percentage of their overall weight, making it easier to account for an empty vehicle, or a loaded one
 
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our trucks came with 0.5" of rake, the second gens actually came with -2" of rake, the wheel well was just lower in the back. what really matters offroad is ground clearance. the front has a lot of clearance, the back is not as good because of the gas tank and lower control arm mounts, so its better to have some rake to maximize on ground clearance without having too high of a center of gravity. plus its easier to lift the back more and maintain good ride quality.
 
IMO the 2nd gen 4Runner is probably the worst saggy ass vehicle on the road.

The OME setup on my Lexus sits a good 2"-2.5" higher in the rear than the front. I believe it was designed for hauling everything (including the kitchen sink) around in the back. Equally annoying, IMO.
 
If I asked my wife about SAS.

She would say we cant afford Solid Axle Swap!

You better keep her then. My FG told me to get the SAS truck and not the saggy ass one....

I guess that is why she is going to get a very nice rock....

Blue
 

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