What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Listened to some folks here and now I'm peeved

Desert Rat

Desert Rat

Fetch the comfy chair
Joined
Oct 19, 2002
Posts
16,246
Reaction score
15
Location
Tri-Valley, NorCal
Listened to some folks here and now I\'m peeved

Six inch lift on the 76 blazer with TC 6 inch springs up front, ORD shackle reversal and 2 inch TC springs in the back. Based upon recommendations here, I ordered a set of the maximum length Bilstein 5150 shocks. Problem is, upon installing the rears, there is only 6 inches of shaft exposed. Which means only six inches of compression before it bottoms out right? Total shaft length on these is 14.53 inches. On the front, I bought some Ford shock towers. Using zip ties, I put the shocks at the exact middle with 7 1/4 inches of shaft exposed and put them up to mark where the Ford tower will be mounted. Low and behold the tower is way to far up and hits the back of the firewall. You can't move it forward because the small hump from the old shock mounting is in the way. If I move the tower down to where it should be (based upon pics and the write up), there is only about 6 inches of shaft exposed, meaning once again most of the shaft is still in the shock.

Now, I have a 1 inch zero rate that might be going into the back depending on if it sags when I am done. I'm guessing that will give me a little more lift and expose more of the shock in the rear. But the front is definitely a problem. Anybody else run into this? Now I'm thinking I should've ordered the next smaller 5150 which has a shaft length of 11.93 inches instead of the 14.53 I got. /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif
 
Re: Listened to some folks here and now I\'m peeved

flex the rig before you go buying more shocks.
6" springs won't flatten out as much as you think they will have more droop then compressions o you can mount them lower on the chassis to allow for this, same in the rear. if you do wanna get different ones let me know I'm looking for the longest shock possible that i can afford and have some Dt 8304's that are 13" travel i think.
 
Re: Listened to some folks here and now I\'m peeved

I have less shaft exposed then you on the back and don't have a problem. On the front it is set up just enough to clear the firewall. You will get more droop then you will stuff so it should not be a problem. If it is a problem just put some longer bumpstops on. Flex it out first before changing anything.
 
Re: Listened to some folks here and now I\'m peeved

what they said. You'll never use all of your compression. Droop is what ya need. I mounted my dt8403s in the center, cause I didn't know and I've never even come close to bottoming out on the compression end of things, but I can just about max out the droop on a rear shock.

mount the 250 towers as high and as close to the firewall as you can and still get a nut/bolt for the shock on there and you oughta be good.

j
 
Re: Listened to some folks here and now I\'m peeved

My 15" travel shocks only need 4" to stuff on the rear and 5" on the front. I have them set for for 6" in the rear and 5 1/2" in the front. Do some flexing and some math and you will figure it out. Hell I almost max them out on droop set like that /forums/images/graemlins/shocked.gif
 
Re: Listened to some folks here and now I\'m peeved

yup I have the 15" travels with the ford towers also and I left 5" of the shaft exposed. works great. I think you are trying to get to much uptravel.
 
Re: Listened to some folks here and now I\'m peeved

Keep talking, I'm starting to feel better about it. I need to do some flexing and check out how it works then. I have some 4 inch bumpstops coming from ORD for the front. Do I need them for the rear or will it come anywhere near that much compression?
 
Re: Listened to some folks here and now I\'m peeved

Why are you using bump stops for 6" of lift???
 
Re: Listened to some folks here and now I\'m peeved

doesnt every suspension need bumpstops? links, ends, springs, shocks etc... none of them should be the max limiting factor on how far your suspension moves. Thats what lim straps and bumpstops are for. Factory rigs have them with (obviously) no lift at all.

j
 
Re: Listened to some folks here and now I\'m peeved

so then why try to get all the flex you can out of your suspension??? with a 6" normal lift you wont have enough travel to mess much stuff up.
 
Re: Listened to some folks here and now I\'m peeved

Suspension travel without control breaks things.

EVERY suspension should have bumpstops and at least a center limit strap.

A shock is not a limit strap or a bumpstop, or a substitute for either.

I thought me breaking my HAD front shaft should have clued y'all into that.
 
Re: Listened to some folks here and now I\'m peeved

im not saying that the shock should be the limit, all im saying is that if your suspension only moves say 5" then that is not going to be enought to break stuff.
 
Re: Listened to some folks here and now I\'m peeved

[ QUOTE ]
im not saying that the shock should be the limit, all im saying is that if your suspension only moves say 5" then that is not going to be enought to break stuff.

[/ QUOTE ]

Your suspension will move until something stops it. If there is enough force on it, it will move until the shock stops it unless there is a limiting strap. Trust me, I know.

That's why there is a tab welded to my Dana 60 and a chain running from there to the frame.

Once again.....

Suspension travel is worthless without control.
 
Re: Listened to some folks here and now I\'m peeved

your leaf springs will only move so much unless somehting else gives. I see no reasont to run bump stops or limiting strap unless ur suspension us super flexy to where if you iver flex you break, I am not going to debat over this all night, this is how I feel and you have another opinion so what not everyone has to think the same way you do.
 
Re: Listened to some folks here and now I\'m peeved

With stockish springs and "normal" lifts, limits straps are rarely needed for leafs. However, the minute you go to something like 63" springs with long angled hangers, or Springer/AK-57 setups, then you are potentially going to exceed your shocks travel. Even if you run hoops and super long travel shocks, you may have shaft problems as mentioned.

Similar for up travel, except it's more likely to be an issue with body/frame interference, steering components, OR shock travel limits. Many after market lifts in the 4-6" range do need lowered bump stops and more complete kits will come with them. The only ones that *appear* not to need it are the ones that are so stiff and binding that they can't reasonably be forced too far *in normal scenarios* to be a problem. Not running bump stops can lead to over flexed, fatigued springs and other damage including suspension components and shocks. In my case I had to lower the stock bump stop brackets in the front to keep the tires out of the steering box and prevent steering linkage interference. In the back, I use a central bump to keep the diff out of my gas tank.

In general, when your going beyond the normal packaged lifts and trying to push the limits of flexy, slinky suspensions, you want build the suspension to go beyond what you need. Then you can easily tune it with the straps and bump stops as needed. You can then make other changes to relax those constraints if you determine the need or find the time/money/way to address other things that required constraining the suspension.

And finally, don't forget that the bump stops (and strap) are inboard of the tires so they act as a fulcrum with the axle as a lever. This allows more movement than is at first apparent since bump stops compress and what appeared to be 4-5" of up travel at the frame may be as much as 8-9" up travel or more at the tire, depending on how far the other tire can drop and other suspension characteristics. That also means that you may need a 4" gap at the bump stop for a shock set at 5.5" (or even more!) of up travel to keep it healthy and alive.

And even this long description is vastly oversimplified since it does not even begin to consider things like deflection, lateral shift, and so on... The more you look at it, the more you realize that nothing in suspension is simple. It only appears that way until you *really* try to figure it out. And the "simple" leaf suspension can be one of the most difficult to understand. Unfortunately for me, I only understand just enough to realize I don't have a clue...
 
Re: Listened to some folks here and now I\'m peeved

Very well said Russ. /forums/images/graemlins/thumb.gif /forums/images/graemlins/waytogo.gif /forums/images/graemlins/peace.gif
 
Re: Listened to some folks here and now I\'m peeved

I was already to spout off the simple tech geometry of normal leaf springs then I scrolled down, saw your post (very complete) and decided to put very little useful info in my post. I have my bump stops set about 4" above the u-bolt plate (part that will hit the bump stop). My shocks show about 5" of shaft and with the stops touching the shocks have very little movement left. My x-over pitman arm might smack the spring if I allowed any more up travel.
 
Re: Listened to some folks here and now I\'m peeved

Keep in mind many lift kits require you to use their longer bumpstops if it comes with a warranty (think I saw that on Trucks!). If you have no bumpstop and over compress your springs to where they negative arch it usually means you destroyed the spring. It will never have the same lift and tension characterists.
 
Re: Listened to some folks here and now I\'m peeved

If the shock was vercial to the travel of the axle this would be an issue.

The shocks are at a angle and that angle increase as the suspension compresses. So while you have 6 inches exposed your looking at closer to 10 inches of up travel at the shock mount on the axle to bottom that shock out.
The spring is a pivot point. If you jumped the truck then you might get the suspension on both sides to compress the same and only see 8-9 inche of compression. Thats not going to happen crawling. Typically one side of the axle is going down while the other is going up. So on the compessed side at the spring the axle may only travel up 8 inches the wheel that ist center line is another 10 icnehs out will have travels 14 inch. The other side may have Dooped as much as 18. So by my calculation for crawling speeds you have over 30 inches of potential wheel travel at the center line of the wheel.

Does that Gell?
 
Re: Listened to some folks here and now I\'m peeved

Everyone concerned ought to take Zip Ties and put them tightly around their shock shafts before their next trip wheeling. They will get pushed down to where the shock shaft traveled the farthest and stay there. You’ll know soon enough if you’re bottoming out on your shocks and not your bump stops. Jack your vehicle up from the frame and with the tires and wheels off the ground disconnect your shock from the axle shock mount. If the axle droops some more, you are using your shocks as limit straps (not a good idea) and you should add limit straps or longer shocks. It ain’t Rocket Science!
 
You must log in or register to reply here.

Latest Posts

Top Bottom