First of all, sorry to ask yet another shock question......but my questions are fairly specific (I hope).

O.K., like many on this forum I too want to raise the front of my truck (05 2500HD) to level it out. I want to do it right and use the Cognito kit but don't have the cash for it right now. But, I may have an opportunity to get new shocks for the truck for Christmas. So, in light of the fact that I will be raising the truck some time next year, and, if I am purchasing new Bilstein shocks now, which ones should I buy (that will work fine now, and then with the cognito kit).

Stock Bilstein FRONT replacements : BE5-6081 HO

2 inch longer FRONT replacements : BE5-6140 HO (actually for a F250 but they fit)

or...5100's or 5125 ( I don't really know what the P/N number is for the 5100 series for the front of my truck) and I'm not sure what the benefits of this series shock is over the 6081 other than being longer.

ANyone have the actual P/N for the 5100 series shock for the front?

Or, should I just wait until I put the cognito kit in? (I'd really rather get the shocks in sooner than later.)

Thanks for any thoughts.

DEWFPO

I would suggest the OEM replacement units and the Cognito kit will have you covered with the lower shock mounts.

While I don't like the idea of spacers on stock shocks you DO NOT need 2" longer shocks.

Keep in mind that you are dealing with a motion ratio.

Think of it in terms of a teter totter. A foot from the fulcrum may only move 6", but the very end could be moving 5 feet.

So 2" of lift at the tire/fender opening doesn't take away 2" of shock travel.

While I don't like the idea of spacers on stock shocks you DO NOT need 2" longer shocks.

Keep in mind that you are dealing with a motion ratio.

Think of it in terms of a teter totter. A foot from the fulcrum may only move 6", but the very end could be moving 5 feet.

So 2" of lift at the tire/fender opening doesn't take away 2" of shock travel.

That is correct, however the point is that the oem replacements are worthless on the raised front end, due to travel limits. A spacer OR longer shock is needed from experience.

1/2" to 5/8" will allow you to contact the OE service stops. These are the brackets on the fram that stop the suspension from collapsing if the shock is removed.

I have 3 points here:

1) If you really needed the 2" longer shocks then you'd be plunking the upper a-arm off this stop and it would show.

2) You do NOT want to do this...

3) A small increse in shock extension will eqaul a lot more travel at the wheel due to motion ratio as mentioned above.

Also IF you go to the Cognito front end kit, you will have brackets that allow more travel. Keep in mid that the higher you go, the worse the bump steer, and camber changes are.

Bear with me here I've not swapped out my shocks yet or for that matter looked really close at them.

Raising the truck takes away rebound travel. But like I mentioned if you raise the truck a full 2" the shock is probably only seeing 3/4". Is that to much?! I sure wouldn't think.

How much droop travel does the truck have at stock height before the shock fully extends? (In this case I beleive that they probably do NOT fully extend).

What I'm thinking is that yes you are losing rebound travel, but on highway conditions it should be a problem as you aren't 'hanging wheels' on the highway. But could be a problem off road when the truck could see more droop travel.

What is the extension or droop limiter at stock height?

I'm trying to fully understand what's going on here. I know that shocks are very important, and based on my experience with the Camaro I just can't buy something just because it fits. Or just because someone said so.....

Not trying to sound like a jerk either. I think that with some of my shock experience that I could help others to come up with the 'BEST' solution for a front shock on a cranked T-bars truck.

I added approx 1" total spacers, and I just touch the a-arm stop now, if I jack it up, I no longer top out the bilstein. I did an article a year ago, using washers (top), and homemeade lower spacers (bottom). The ride difference was substantial. A 2.5" torsion lift, leaves less than 1" of downtravel, terrible ride quality, even on highway, IMO.

Wish the lower spacer was available separately.

So if you totally skip the spacers you will be using the shock as a droop limiter. Yeah that's really bad. Especially with all of the weight pulling on the shock.

What is the upper A-arm stop? Is there a soft bump stop for the upper arms, or is there simply metal to metal contact?


I still think the best option is a Bilstein 5150 on a shock hoop. This gives you a nice long shock and travel will no longer be a problem. Bilstein should be able to revalve/rebuild them as everything they sell is rebuildable/revalveabe.

I would base the valving of this shock on the factory replacement Bilstein. We know that shock works well. I would however reduce low speed compression a little as this would reduce the 'hit' from the stiffer front end that a cranked bar truck will have. Then again because of the added spring rate of the pre-loaded bars I woudl increase medium speed rebound some to prevent the cadillac float on highway dips.

I would then add a limiter strap to limit droop. This way you aren't relying on metal to metal contact, the shock itself, or resistance (as in bind) in the suspension links, swaybar links, or CV joints.

And then sense the factory bump stop DOES contribute to the spring rate of the truck I would probably build a spacer to space the factory bumpstop back to the original type location. Meaning almost touching.
This I would definately test out though as the ride could be better by not being on the stops.

This of course would be for some bling factor. But honestly, I can't see any disadvantages except maybe cost.

If I do go with the stock type Bilsteins (becaue of cost my preferred setup is what I mentioned) I will still get them custom valved. And definately build the spacers.

On the spacers....I would rather have a shock valved for OUR trucks taking into account T-bar rate, swaybars, weight of the truck etc,etc, and use spacers than a shock tha fits better but is valved for another truck.

metal-metal

I agree on spacing the jouncers also, but good luck with that.
I think it would be good ride (and less stress on the T-bars) if they touch.

The Bilsteins at this level are not rebuildable/revalveable. The custom revalve charge on a new shock is near the retail price of the shock itself. The shock has been designed in as the travel limiter.

...The shock has been designed in as the travel limiter.
No shock should be used as a suspension limiter.

Last I knew Bilstein was only charging $65 to revalve shocks. This was early this year. Of course that was on Car shocks, but the design is the same. Only difference being the truck shock is bigger. I'm comparing car HD to truck HD's (which is what everyone is buying)

All Bilsteins like I mentioned are rebuildable/revalveable.

I'd have to call them to get exact quotes on the 2500 shocks but like I said, the car shocks were only $65 apiece. FWIW I also had a set of car shocks shortened for a lowered application and that was damn cheap too. They are very reasonable with the custom work.

No shock should be used as a suspension limiter.

Well it is in this case. Same with 6" Fabtech lifted truck I had on the hoist...

That is correct, however the point is that the oem replacements are worthless on the raised front end, due to travel limits. A spacer OR longer shock is needed from experience.
Ding, ding, ding....we have a winner!

The shocks cjsho mentioned are valved similar to the Bilstein BE5-6140 I am running. They are longer than the OEM replacement Bilsteins but shorter than the BE5-6140. Any shock used as a limiter will fail prematurely as they are not designed for that purpose which is exactly why Bilstein designed a longer shock at ORU's request. If you do not use a shock extension go with either the BE5-6140 or 60007-BF; both are longer and valved properly. If you buy the Cognito kit and use the extensions than the OEM replacement Bilsteins will work. If your suspension kit uses the shocks to limit travel you have a problem!

The mechanical stops have not moved. You can add all the shock length that you want, but the fall out stop on the frame will ne the limit. You can get there with the stock shocks and a spacer BUT do you really need to?

With all of the 2" over shocks/green keys/jacked fronts out there, you'd think SOMEONE would hear the upper a-arm hit the mechanical stop, yet nobody that I have heard of has complained. That's because you don't need that much for 99% orf the vehicles out there and if you need to go further then teh Cognito kit with the revised upper a-arm is needed. This kit has taller lower shock mounts so again no need for longer shocks.

Like it or not, GM designed the shock as the travel limiter and Bilstein matched the length on their OE shocks. Fabtech also apparently chose to use the shock as the limiter as well.


As for revalving shocks, Bilstein will do it upon initial build as previously stated. Cost is equal to the price of the shock itself. Once the shock is assembled, it is NOT designed to be repaired or serviced. To get this we need to go to a much more $$ series...

Kennedy. Do you know if the stock Rancho 9000X's fall into the same category as the Bilsteins as far as being designed to be the downtravel limit?

ORU also includes a small bumpstop for the upper a-arm with their torsion keys to avoid the upper arm hitting the mechanical stop.----

I wonder why they chose such a long shock? The OE length shocks (I'd be pretty certain Ranchos are also OE length) can get you to point of contact or pretty darn close.

As for revalving shocks, Bilstein will do it upon initial build as previously stated. Cost is equal to the price of the shock itself. Once the shock is assembled, it is NOT designed to be repaired or serviced. To get this we need to go to a much more $$ series...


That's NOT true. Many people have this misconception simply because of the way that the higher end shocks are marketed.
The higer end 7,000 and 9,000 series shocks are USER REBUILDABLE AND REVALVEABE. That simply means that they are disigned to be easily taken apart and put together. And include a shrader valve for recharging the Nitrogen.

These shocks are simply impractical and for ANYONE short of offroad racers a complete waste. The shocks are all the same. A monotube is a monotube. (granted some are larger, some with resevoirs etc, but like I said if you aren't an off-road racer who cares). Shim stacks are actually pretty cheap so if you have an idea what you need/want to do that isn't that bad. The re-charging equipment is actually quite expensive. And you need a few other tools. Like I said not practical.

BUT, all Bilsteins are rebuildable and revalveable, and are made to be rebuilt. You just have to send them to Bilstein. They will also revalve USED shocks, and do it for a relatively small fee. And they do it on regular old off the shelf stock type replacement shocks.

When I had shocks rebuilt/revalved/shortened for the Camaro it was done on a set of used shocks. And FWIW those shocks are SO much more complicated that I can't spec valving's for them (and neither could Bilstein) but Sam@StranoParts.com did. And to give you guys an idea, those shocks were valved based on tire brand, size both front and rear, bushings, spring rate front and rear, swaybar size front and rear, weight of the car, primary surface, ride height, etc,etc.

FWIW Sam also sells the stock Bilsteins for damn cheap. The site stinks but he'll send you a quote right away. In fact I'll check with him and post back. He owns a Dodge though....

Kennedy you are partially correct but some of your information is incorrect. When the suspension is cycling at full drop the A-arm should be your limiter not the shock. If you use the OEM Bilsteins you WILL have a problem should you ever go offroad and are at full drop. Yes 99% of the time people, including myself, will not encounter this problem but I like to do things right 100% the 1st time. As to why ORU and myself are running longer shocks...there is your answer. Also as BlackCrewCabDuraMax mentioned almost all Bilstein shocks are rebuildable. I know for a fact my front 5125's are but 5150 series are not.