How Much Travel in the Rear?

[Plainview]

I'm wondering if there are any guidelines concerning how much suspension travel I should have on compression in the rear.   Using the extended bump stops I got from Marlin (https://www.marlincrawler.com/suspension/parts/bumpstop-large)  will give me about 4" to 4.5" of clearance before the bump stop contacts the bracket on the frame at my current ride height. 



I expect this will decrease some as the springs settle and the ride height lowers a little.

Does that seem like too little?

This also plays into my shock choices.  When the bump stop contacts the frame there is 18" distance from center to center of the shock mounting studs.

If I go with the Rancho RS999143 I will have an additional 2" of bump stop compression before the shock bottoms out (they have a 16.05" compressed length).  I don't imagine I'd be compressing those bump stops by a full 2" under any kind of normal conditions...?

How much clearance do you like to see between when the bump stop contacts the frame and the shock is fully compressed AND is ~4" clearance between the frame and bump stop reasonable or will it cause problems in normal driving?  (Don't want to be bouncing off the bump stops all the time).

Thanks for any input!

[kneedownnate]

The way most seem to set their bump height is to flex the spring until it's nearly flat and set the bump so the spring is not quite flat, so when it compresses the rubber/eurethane a little the spring will still not go negative.

[Plainview]

Well, that's good info, thanks!  I wonder if I have enough old engine blocks around here to weight the rear down enough to flatten the spring... LOL!

Do you think it will work as I have it now?

[84Flatbed]

A floor jack might get you high enough if your not on big tires, otherwise a bank or rock work nice to flex the suspension. What your showing there would probably work fine, you could always cut them down some if need be.

[Plainview]

Hmm, I'll have to try that - putting the jack under the spring perch.  Not sure if I can jack it high enough without lifting the whole back of the truck though without adding weight.  I'm running 32s.

If I cut down the bump stop then that gets me closer to the point of the shock being fully collapsed when the bump stop hits the frame.  How close can I come to full shock compression when the bump stop meets the frame without risking damage to the shock?

[emsvitil]

I wouldn't cut the bump stop until you see if the bump stop is even being hit.............

[Plainview]

Well yeah, I wouldn't alter anything unless I had to.

Question remains - how close to full shock compression can I get when the bump stop hits the frame and be safe?

[84Flatbed]

Those bump stops will compress some but I wouldnt think much more than 1".

[Plainview]

I wouldn't think so either but thinking has gotten me in trouble more than once.  Thanks!   

[blackdiamond]

Well yeah, I wouldn't alter anything unless I had to.

Question remains - how close to full shock compression can I get when the bump stop hits the frame and be safe?

It probably depends on how hard you hit the bottom.  When I first built my 4Runner I had Bilstein shocks, 5125's I think, that I was bottoming out constantly on my trip to Moab.  It was bad enough that I had a local shop install some bump stop things that went right on the shock to cushion the eye from the shock body.  It was a preventative measure.  I replaced the shocks with Rancho 9000s and will still on occasion feel the bottom of the shocks, but now it's a couple times over the week in Moab instead of 10x per day.  I am sure that bottoming them out will reduce their life, but unless you're hitting them hard I wouldn't necessarily expect an immediate failure.  I don't even run bump stops as I have never seen a springs over compressed and rarely bottom a shock anymore.  A lot of it is my easy driving style.

[84Flatbed]

I know bilsteins die quick from bottoming, I've seen it with the 5125's and 5150's.
I have similar bump stops on my tacoma, in this picture it looks like those stops would compress more but they are pretty solid at that point, I tried with my body weight on that corner and couldnt get much more out of them. The oposite tire is just about to lift off the ground. I could probably cut down more or get rid of my stock bs but this is flexed and straight up and down affects the travel differently.

[emsvitil]

Put a tie-wrap around the shock rod to see how close it comes to full compression.

[LittleSteve]

Or, take the leaf pack to bits and re fit just the longest with the bushes in it then pack that out with flat steel and box section till its as thick as it should be. Reasemble with shackles as it should be.
Then take a rachet strap and pull the axle to the chassis till its almost flat, then as the others have said measure up and fit shocks etc. because it willl be so soft you will be able to jack the chassis up and weight the axle down to make sure your shocks have adequate extension. Then when youve got everything figured reassemble and grease the contct areas of the springs, dont be shy with it.

[Dirt Mover]

Use some string and stretch it from eye to eye and measure how much arch you have in your springs. Set your bump stops gap similar to your arch height. Since you're running 32s I'd guess you're not running lockers or an ultimate so with your set up I would doubt you'll be putting a negative arch in the springs.

[Plainview]

Thanks for all the suggestions.  Dirt Mover - that's the easiest one yet!