Busted another Bilstein 5150.. Anyone using the 7100's or have a recommendation?

[goldensd]

Had another awesome trip this weekend through Barrett Lake. Made all of the hardest lines without getting hung up, or much carnage.

I did however manage to snap the bottom of the shaft on one of my 5150's on one of the obstacles near the end of the trail. At least it gave a good reason to try out my buddies home made welder he made by adding a second alternator and removing the regulator to give about 70-80 volts to stick weld with. It worked sweet and only took a few minutes to fix up after we got off the trail.

I've been waiting for this to happen, as there just doesn't seem to be enough movement in the bushing to account for the amount of angle change I get over the full part of flex.

Anyways, I've been eyeing the short body reservoir 7100's for a while, but was waiting for a justification for them. Now that I've got one, I thought I'd check to see if anyone has some experience with them. I'm looking at these for a couple reasons:

1. The heim joint style ends should provide more movement without the binding
2. The short body's are the perfect length for me to go from a 10" to a 12" shock, and be perfect for where I need to set my bumpstops for rubbing.
3. Heavier valving. I'm currently running the 255/70 which is perfect at the start, but with my weight (6,000 lbs) they quickly fade and get pretty bouncy. Thinking the 275/78's might help a little with this, without being too harsh on the road.
4. Rebuildable - Can't hurt, and would make these the last ones I should ever need to buy.


Any opinions on these or any other shock I haven't found that fits this bill are appreciated.

[SirFuego]

I took a look at your build thread to remind me of how you've done to your rig. I have a couple questions regarding your shock failure.
1) Any chance the shock skid plates you built are hitting the shock when you are flexing (or do they possibly move when you drag the skids over a rock)?
2) Are you running any type of limit strap?

The only reason I ask these questions is because I've been running a setup similar to yours for the past couple years and never noticed any binding with the triangulated shock setup. I don't jump my rig or really do any high speed stuff, though.

[IndyZJ]

Are you running limit straps like you should be? That would be a MUCH cheaper way to keep shocks alive. Which style mounts are you using, and how are they oriented? A pic could help.

IIRC, the bottom eyes on 5100 and up Bilsteins are removeable and interchangeable if you really need the rod ends, but IDk if that would really give you any more angularity. If you REALLY want the 7100s, I would still try to figure out what's going on with your mounting situation before you ruin a more more expensive set of shocks, too.

ed: Damnit, Fuego typed faster than I did.

[cowboy63b]

I did however manage to snap the bottom of the shaft on one of my 5150's on one of the obstacles near the end of the trail. At least it gave a good reason to try out my buddies home made welder he made by adding a second alternator and removing the regulator to give about 70-80 volts to stick weld with. It worked sweet and only took a few minutes to fix up after we got off the trail.

[chadjans]

The misalignment on the spherical bearing shocks with misalignment spacers is not that great.

Are you running limit straps? How are your mounts phased in relation to the axle? Bolt running front to rear or side to side, top and bottom?

How big is the shaft on a 7100? That is alot of coin to be droping on a 10 or 12 inch shock. Almost a waste really.

[goldensd]

Thanks Guys, Here's a little more info:

It's actually my front that is the problem, rears work great.

I've got the top mount running parallel to the axle (side to side), and the bottoms perpendicular to the axle (front to rear). I know when I did it this seemed to the best orientation for the axle movement, but maybe its not. At ride height, the alignment looks pretty good, but when it drops, it looks like it needs a little more flex in the bushing.

II do have limit straps installed, and they get tight before the shock max's out.

I know that I still need to finish my real bumpstops, but all of my stuff is crawling in the rocks, and judging from the way this one broke, I'm pretty certain it wasn't from slamming down on it.

I didn't get any pics yesterday, but here's a couple old ones to show the orientation. I used the ballistic mounting plates when I put this together.






Looks like the 7100's would have a 14 mm shaft.

[IndyZJ]

It's hard (if not impossible) to tell from the pics, but is the shock bushing already binding at ride height? It almost looks like the bottom shock bolt is horizontal while the shock is a few degrees past 90 to it at ride height.

[SirFuego]

I would rotate the top shock mount 90 degrees which would allow both the top and bottom to be oriented "front to rear". If you think about it, that's the same way the rears are oriented -- just at a less extreme of an angle. With long arms, the axle doesn't move much front to back, but it does move side to side when flexing. Having the mounts opposing each other is probably creating a good bit of binding.

[goldensd]

It's hard (if not impossible) to tell from the pics, but is the shock bushing already binding at ride height? It almost looks like the bottom shock bolt is horizontal while the shock is a few degrees past 90 to it at ride height.

I looked again tonight, and it might be a little out of plumb, but very slightly, and actually to the opposite side that it goes against as it drops. Actually, now that you've got me thinking about it more, I wonder if it gets bound more at compression, than extension. I'll have to play around a bit more with it.

Thanks

[goldensd]

I would rotate the top shock mount 90 degrees which would allow both the top and bottom to be oriented "front to rear". If you think about it, that's the same way the rears are oriented -- just at a less extreme of an angle. With long arms, the axle doesn't move much front to back, but it does move side to side when flexing. Having the mounts opposing each other is probably creating a good bit of binding.

I'll look at it and see, I see your point, but it seems like it would still create some pretty bad binding with both points front to rear. I'll have to play around with it some more.

Thanks

[chadjans]

but it seems like it would still create some pretty bad binding with both points front to rear.

Both bolts running front to rear allows the bushing to rotate around the bolt as the suspension cycles. Then the only loading you will see is as the pinion rotates. Which is why I think you are breaking shocks.

[goldensd]

Both bolts running front to rear allows the bushing to rotate around the bolt as the suspension cycles. Then the only loading you will see is as the pinion rotates. Which is why I think you are breaking shocks.

Thanks, I'll may just weld it back up, spin the top and see how it goes for a while. It's actually only the 2nd shock that's broke over a few years, so it hasn't been overly bad, and if I remember right, the first might have been due to lack of straps. That said, maybe I can keep these going for a while.

[Mochisme]

Good question and comments from others. Now I have to go look closer at my shocks as I have busted four Bilsteins 5150's, all on the left rear and two of them at the last GSW.

I have limit straps on the rear, but not the front and like I said I only bust the left rear shock. Those thqat have looked at it could not make any suggestions, or see a problem. Have to see what I find, as I seem to recall all four of mine have the mounting bolts running with the axles.

[AgitatedPancake]

That's gotta be a Bilstein defect of some sort...that's odd

IIRC Gold your running the same ballistic lower mounts (or copies?) as I am, with basically the same exact mounting configuration. The only difference is I'm still running the stud up top. The crazy think is I have 12" Rubicon Express twin tube dirt cheap bad mamma jammas, do NOT have limiting straps and I've never had a problem with them.

[SirFuego]

I have limit straps on the rear, but not the front and like I said I only bust the left rear shock. Those thqat have looked at it could not make any suggestions, or see a problem. Have to see what I find, as I seem to recall all four of mine have the mounting bolts running with the axles.

Are you still running the stock shock setup? What type of material is the bushing?

Keep in mind that we are flexing our axles at a MUCH more extreme angle than the Jeep engineers ever designed it for. In minimal flex situations that type of orientation is fine. However, once we start to lift a vehicle and put more extreme angles on the axle while flexing -- this creates a lot of binding in the shocks with that orientation (possibly to where the misalignment allowed by the bushing isn't enough). That said, this design is basically immune to damage due to pinion angle changes.

Once you rotate the shock mounts to run front-to-rear, the shocks can now just pivot around the bolt while you are flexing -- but like Chad said, that orientation can cause binding if the pinion angle changes as well as the axle moving forward and backward. The big difference here is that since we mostly rung long arm suspensions, the pinion angle changes and axle movement creates much less severe angles than flexing. The bushing has very little problem dealing with that.

I know I sort of verbosely expounded upon Chad's comment, but it seems that you are running into the exact same issue.

Folks running coilovers can be a little bit more liberal with their mounting options due to misalignment spacers they can use.

[goldensd]

That's gotta be a Bilstein defect of some sort...that's odd

IIRC Gold your running the same ballistic lower mounts (or copies?) as I am, with basically the same exact mounting configuration. The only difference is I'm still running the stud up top. The crazy think is I have 12" Rubicon Express twin tube dirt cheap bad mamma jammas, do NOT have limiting straps and I've never had a problem with them.

Yeah, I believe we are running the same mounts. I do think that the break was at the winkest link since it broke in the middle of the section that has the threads cut in the shaft, but it had to be a result of either excessive binding or fatigue from minor binding to have caused it. Who knows, maybe the having the stud up top helps provide a little more cushion and movement for the bottom bushing.

Speaking of the upper stud, I wish Bilstein would hurry up and get their new 5160's out, I'm curious what specs/pricing there going to have to them since I've seen them with the upper stud mount.