Bump stops

[PatrickH]

So I just switched from 4" Superlift front springs to Tuff Country EZ ride 4", and from 4" blocks in the rear to 4" shackle flip. How much up travel (compression) should I allow for, especially in the front? I do have a Warn 8274 on the front, but nothing else heavy. I don't want to over compress the springs and cause un necessary fatigue making them sag prematurely. I've ordered 4.5" bumpstops, but that only gets me around 2 /2-3" lower that the factory bumps. Will the 4.5's be enough.? What are y'all running for bump stops with 4" lift"?

 

[K5wrench]

So I just switched from 4" Superlift front springs to Tuff Country EZ ride 4", and from 4" blocks in the rear to 4" shackle flip. How much up travel (compression) should I allow for, especially in the front? I do have a Warn 8274 on the front, but nothing else heavy. I don't want to over compress the springs and cause un necessary fatigue making them sag prematurely. I've ordered 4.5" bumpstops, but that only gets me around 2 /2-3" lower that the factory bumps. Will the 4.5's be enough.? What are y'all running for bump stops with 4" lift"?

I have just installed the same setup; 4" shackle flip lift rear(8"), 3 inch Tuff country HD springs up front.
Sway bar disconnect kit.
Can't find any info about moving bump stops.

 

[PatrickH]

I just had my Son's '91 out; he has 2" EZ rides and a 2" shackle flip, with 3" aftermarket bump stops. I buried both front and rear tires in the fenders, and it's still several inches from the bump stops.

 

[K5wrench]

I just had my Son's '91 out; he has 2" EZ rides and a 2" shackle flip, with 3" aftermarket bump stops. I buried both front and rear tires in the fenders, and it's still several inches from the bump stops.

So would you say lowering the bump stops is unneccesary?
I assumed ORD would have mentioned it if it was.
I can't see how the springs could be over compressed as the axle would hit the stock bump stop at some point.

 

[PatrickH]

So would you say lowering the bump stops is unneccesary?
I assumed ORD would have mentioned it if it was.
I can't see how the springs could be over compressed as the axle would hit the stock bump stop at some point.

No, they can be over-flexed, and if done enough will fatigue the springs and cause them to sag.

 

[PatrickH]

And this is my Blazer, 4". I really don't want to cut fenders to clear, but I don't want to cut a tire. The Superlift springs wouldn't flex anywhere near this much.

 

[K5wrench]

And this is my Blazer, 4". I really don't want to cut fenders to clear, but I don't want to cut a tire. The Superlift springs wouldn't flex anywhere near this much.

What size tires?
My 33's and 3" dont come near the fender.

 

[PatrickH]

What size tires?
My 33's and 3" dont come near the fender.

33X12.50
The difference could be my wheels; 8" wide but 3 1/2" back space IIRC

 

[K5wrench]

33X12.50
The difference could be my wheels; 8" wide but 3 1/2" back space IIRC

Ahh.
Yes.
I have the stock 15x8 Kelsey Hays military rims and 33x10.5x 15.
Even before the lift, they just barely grazed the back corner of the fender.
I did the lift to improve articulation and be able to disconnect the swaybar offroad without rubbing the wheel wells.
I am still curious about the bump stop issue.
If it only lifted 3", and the stock bump stop is still there, i don't see how the springs could be damaged.

 

[Fastereddie]

The stock bump stops are set up for the stock spring which is a negative arch. You want to bump stop it so your spring doesn’t go any further than flat. Whatever that distance may be.

 

[K5wrench]

Maybe ask ORD about this.
Or hopefully someone on here can chime in.

 

[obijuank5]

I used the universal poly bumpstop and just bolted it in place of the stock one.

It was really half ass but has stayed for years that way. I just stacked some washers.

 

[K5wrench]

I used the universal poly bumpstop and just bolted it in place of the stock one.

It was really half ass but has stayed for years that way. I just stacked some washers.

View attachment 264843

You know, ORD doesn't even list extended bump stops as part of their complete lift kit.
I'll call them tomorrow and ask them what they recommend.
They were very helpful.
I will report back my findings here.

Edit; fired off an email to Chris at ORD.
I personally would rather not have any more bump stop than neccesary.
The point of my lift and sway bar disconnect was to improve articulation and i want to stuff that front tire as far as possible without damaging the springs.
So I asked Chris his opinion based on a moderately wheeled rig; what are the criteria to determine bump stop height for rigs lifted like ours etc.
Added the part about not allowing the front lift springs beyond flat.

Now I have seen plenty of Scouts and Blazers push their springs pretty far.
Just can't honestly remember if their lift springs went beyond flat and inverted.

This seems like a great question that may have a lot of different answers.
Well, i'll let you know what I find out.

 

[Blue85]

There are too many variables to say that all 4" lifts need the same bumpstops. They have maybe 4 purposes:

1. Keep stuff from hitting. Most importantly tire to fender, diff to oilpan, steering parts, etc.
2. Keep stuff from bottoming out - your shocks and driveshaft - or you cause catastrophic failures.
3. Prevent early fatigue of springs.
4. Absorb some of the force as the suspension bottoms out, so it's not too harsh.

Keep in mind that these limits are different for articulation and straight suspension travel. Only real way to know is cycle the suspension and take a bunch of measurements. Stock rubber and aftermarket poly bumps don't do much for #4, so if you want to hit the whoops fast you'll have to step up to something fancier.

With uncut fenders you can't get much articulation unless the tires are under 30". Even 31s can rub while steering if the springs have much flex. Most who say "no cutting, no rubbing" are running the sway bar or not wheeling it. There is some variation based on backspacing as already mentioned, but you kind of have to try it.

 

[PatrickH]

There are too many variables to say that all 4" lifts need the same bumpstops. They have maybe 4 purposes:

1. Keep stuff from hitting. Most importantly tire to fender, diff to oilpan, steering parts, etc.
2. Keep stuff from bottoming out - your shocks and driveshaft - or you cause catastrophic failures.
3. Prevent early fatigue of springs.
4. Absorb some of the force as the suspension bottoms out, so it's not too harsh.

Keep in mind that these limits are different for articulation and straight suspension travel. Only real way to know is cycle the suspension and take a bunch of measurements. Stock rubber and aftermarket poly bumps don't do much for #4, so if you want to hit the whoops fast you'll have to step up to something fancier.

With uncut fenders you can't get much articulation unless the tires are under 30". Even 31s can rub while steering if the springs have much flex. Most who say "no cutting, no rubbing" are running the sway bar or not wheeling it. There is some variation based on backspacing as already mentioned, but you kind of have to try it.

I agree. I was just curious what others were using.

 

[K5wrench]

Still waiting to hear back from ORD.

But been shopping online.
Turns out Energy Susension makes a nice bolt in, extended bump stop.
Oreilly Auto has them on their website.

Part no. 9.9104R
$67.99 each
4-1/2" height.
2-1/2" width.
Polyurethane with steel backing plate.
Stock bumps are 3".
So 1-1/2" extra over stock.
That means only an 1-1/2" spacer and this bump stop would put us back to stock.

Skyjacker makes the same 4-1/2" bump stop but they are $87 each at 4 wheel parts.


I totally get why they are there.
It is odd the total lack of info about them.
Dozens of pictures online of ifs rigs lifted with aftetmarket bump stops.
Very few K5 Blazers or trucks showing them.

 

[PatrickH]

Still waiting to hear back from ORD.

But been shopping online.
Turns out Energy Susension makes a nice bolt in, extended bump stop.
Oreilly Auto has them on their website.

Part no. 9.9104R
$67.99 each
4-1/2" height.
2-1/2" width.
Polyurethane with steel backing plate.
Stock bumps are 3".
So 1-1/2" extra over stock.
That means only an 1-1/2" spacer and this bump stop would put us back to stock.

Skyjacker makes the same 4-1/2" bump stop but they are $87 each at 4 wheel parts.


I totally get why they are there.
It is odd the total lack of info about them.
Dozens of pictures online of ifs rigs lifted with aftetmarket bump stops.
Very few K5 Blazers or trucks showing them.

That's what I ordered, from Summit Racing. I'll machine some aluminum spacer blocks to space them down to the appropriate height.

 

[K5wrench]

That's what I ordered, from Summit Racing. I'll machine some aluminum spacer blocks to space them down to the appropriate height.

I am a little disappointed at ORD.
I sent an email.
I called.
No answer.

The complete 3" lift kit is advertised as containing "everything except the gnomes to install it for you".
I spent $1600.
If I needed another $280 worth of bump stops, fine.
But nowhere are they mentioned.
Nobody at the time I ordered, ever offered.
I assume they would at least mention the issue and offer them.

Well, i will be patient.
The ORD 3" kit is awesome.
Went together easily.
Got the sway bar correction/ disconnect.
Longer brake lines.
Longer shocks.
Improved front shackles.
Greaseable bushings.
Dropped pitman arm.
All of it.

Stands to reason that a bump stop solution would also at least be avaliable.
Hmm.

 

[blazinzuk]

I'm not affiliated with ORD but I would imagine the reason they don't sell a bumpstop with the kit is because it would never be right.

For some the bumpstop would need to prevent a certain size tire from hitting anything. Well that's got at least 3 common variables. Actual tire size and width. Wheel back spacing. Wheel width. All of those could change what bumpstop you need.

Now if it's all about flex that's another bumpstop. But on a spring you still have many different heights in the same spring because if bumpers, winches, engine differences etc. So even if it's all about flex there would be at least a couple you would need to offer.

Now just that your up to 5 or 6 different lengths. That a customer has to choose.

To measure for bump stops properly you need to flex your truck. All four corners. Whether done with a forklift an RTI ramp, a rock, an engine hoist or any other manner all tires must be lifted. Realistically you only need to lift the rear tires to measure for front bumpstops.

If you bumpstop for Max flex you should stop the spring about an inch before it goes dead flat. Bumpstops have some give in them. In reality it depends on your bump stop. Some compress more than others.

That all being said this is a very good option as it's very easy to tune the length of it.
http://diy4x.com/product.php?productid=17758&cat=250&page=1
You can get a longer bumpstop or just reuse the stock.

But it boils down to the fact that alot if different lengths would be needed to satisfy everyone

 

[Blue85]

FYI, ORD sells those bumps for $60/pair: http://www.offroaddesign.com/catalog/bumpstops.htm. If they aren't responding, it's probably race time. You might want to research poly bump stops a bit, as they split under some applications.