Good catch. Will add in AM. Thanks
Rear shock mount bending
- Thread starter kcjaz
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- mount rear rear shock shock
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No rust on LCA’s, they were slick and greasy, just covered in dirt.
I apply an undercoating every fall to prevent rust on East coast. Downside is it collects dirt and mud but doesn’t seem to trap moisture which is a good thing.
I did and it worked well.
Question to the bent lower shock mount folks w/ BP51/BB shock guard issues: Has anyone seen/done a replacement sleeve/stud installation? (or know of a link to such a procedure) Basically replace the OEM one with a new one? My interior threads got super chewed up; not pretty and no longer a smooth threading for the bolt. I've done the bend-back process once before, using a longer interior bolt (little by little) and external sleeve to straighten out...but threads are not doing well. I'd rather not have to replace the whole assembly.
- Thread starter
- #65
Resurrecting old thread. In preparing for Cruise Moab I noticed this that the rear lower shock mounts were so bent that it was impossible to remove my BB shock guards. I had to take a die grinder to the bolt access holes to make room for a socket.
You can see the bend angle in the pic with the socket on the bolt. Heading back from CM, my buddy with the same set up on his 200 noticed his BB guard was hitting the upper shock housing as the 1/4” plate that protects the shock rod was bent in. I looked and had a similar issue. We both remove the bent BB guard on the side of a trail.
The retaining “lip” on the shock rubber bushing is torn off at the bottom. If I hadn’t enlarged the holes, I could not have removed the guard on a trail without a die grinder.
I’m pretty sure that part of the problem is the design of the BB guard itself. The mounting tab that the shock bolt goes through puts the force of impacts on the mount itself. This is made worse as the upper guard bolt just acts as a pivot point. It’s really the forces are the same as if there was no guard. Another factor, discussed in this thread above, is that BP51 shock lower bushing is all rubber with no metal sleeve. This weakens the OEM mount. The combo is bad. Also, the overall size of the guard itself makes hitting it more likely.
I’m going to try to bend the shock mount back but I think ultimately I need to modify this and just go to a through bolt and maybe raise it a bit. I’m not running these guards anymore. There has got to be a better way to protect the mounting bolt and the bottomed of the shock.
You can see the bend angle in the pic with the socket on the bolt. Heading back from CM, my buddy with the same set up on his 200 noticed his BB guard was hitting the upper shock housing as the 1/4” plate that protects the shock rod was bent in. I looked and had a similar issue. We both remove the bent BB guard on the side of a trail.
The retaining “lip” on the shock rubber bushing is torn off at the bottom. If I hadn’t enlarged the holes, I could not have removed the guard on a trail without a die grinder.
I’m pretty sure that part of the problem is the design of the BB guard itself. The mounting tab that the shock bolt goes through puts the force of impacts on the mount itself. This is made worse as the upper guard bolt just acts as a pivot point. It’s really the forces are the same as if there was no guard. Another factor, discussed in this thread above, is that BP51 shock lower bushing is all rubber with no metal sleeve. This weakens the OEM mount. The combo is bad. Also, the overall size of the guard itself makes hitting it more likely.
I’m going to try to bend the shock mount back but I think ultimately I need to modify this and just go to a through bolt and maybe raise it a bit. I’m not running these guards anymore. There has got to be a better way to protect the mounting bolt and the bottomed of the shock.
UPR LC
GOLD Star
Wow, that is crazy. The guard is not the best structural design, but I'm really surprised how much the shock mount has bent downward.
A better design would be a double shear bracket that would use a bolt through the shock eye (with appropriate sized sleeve) similar to the front strut mount.
- Thread starter
- #67
Agreed. You could put in another bolt up top to give you your double sheer and get any force moment off the actual shot mount. I may look at that and just grind off that bent tab on the Bug built guard. You still have a much larger surface to hit and bang though.
- Thread starter
- #68
Here’s another photo of how it was before I left for CM.
UPR LC
GOLD Star
That photo is really helpful.
To me it seems there is something other than shock compression forces that is bending the lower shock "peg".
Is it possible that the axle housing is rotating up (top of housing rotating towards the rear of the vehicle) during suspension articulation, with the additional potential of the shock bottoming out on compression?
The way the bushing and shock guard tab are positioned in the photo, it seems the bending of the shock mount is not happening at that static axle/shock position.
Is there something else going on here, like the the shock limiting suspension travel? I would think the shock skid would be completely bent down like the shock mount.
UPR LC
GOLD Star
Agreed, also seems some sort of rotational issue at play (axle housing rotating) to have that guard tab bent as severely as it is.
- Thread starter
- #72
Good question. At this point IDK. I suppose if the shock hit its travel limit in compression, it could bend the mount pin down (though I’d think if that happened, the shock itself would break). I have over sized Timbren bump stops and I never feel any hard axle axle compression bumps or hits. I used to be able to feel the axle hit the stock bump stops when dropping of a step or ledge. The larger Timbren stops fixed that. There are a few guys who have reported the same mount bend (maybe not as bad as mine) without running the BB guards so maybe there is something with the shock itself (besides the lack of a metal sleeve in the bushing.
I thought everyone who had bent that had the shock guards, but maybe I’m misremembering.
I will say I don’t think the bending is due to overextending or over-compressing the BP51s. I jus checked and mine are still straight and @kcjaz as you saw there’s zero chance of compression was the cause that mine wouldn’t be completely destroyed after that spot in the swell…
- Thread starter
- #75
Jerry had the bent mounts before he had the guards.
- Thread starter
- #76
Seems about right.
I had the same thing happen to one of my Bud Built guards. It lasted me several years. Fast forward, I won a raffle for BB at one of the COTR events and used that to buy a new set. Jason - you may want to send the pics to Bud and Chip, they may consider updating the design.Seems about right.
Yup, all of this. Terrible aftermarket parts design on multiple fronts, and at the core, its poor engineering or lack thereof.
This picture tells the story. Not only are the BB guards reducing clearance and making it more likely to hit things, it's also multiplying it and translating the force into a downward bending moment on the lower shock mounting stud. Which is already weaker than the stock config due to OME not fitting an appropriate sleeve as the stock setup had.
I'll add that the lower offset wheels tend to expose the lower shock mounts more. This is where full fat tires might help in shielding the lower mounts. Perhaps best insurance is mod with more tire (lift) that actually gets things out of harms way than playing contact sports.
Honestly on a new guard you could cut off 75% of the vertical part. You really just want to protect the bolt, and if you have rock guards in your shocks you’re unlikely to hit the shaft before the area protruding around the bolt would hit anyway
I don’t love the design but also trashed a bolt once so they do help.
I don’t love the design but also trashed a bolt once so they do help.