Rear Upper Shock Mounts

[fatbillybob]

Ford putting the joint in bending was the first mistake. There's a reason why most shocks have fasteners oriented in straight tension & compression or in shear (strut mounting).

Agreed! Just another of many mistakes. Guys like me converting from divorced spring and heavy rates following vorschlag's starting point are putting even more force there too. I used to think if shock travel is good there would ne no problems. I'm starting to rething that especially the more rips I see and the fleet ages.

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[Grimreaper]

id sign that. maybe even hold his feet or hands down too.

i swapped back to stock mounts for now. will be back in there for frpp shocks by end of the year and will see how those spots are doing. seems that dimpling on the back of the stock mount is pretty useful to help transfer the load to more than the 3 welds on the nut.

 

[GT 550]

@Grimreaper if you're up for it you could send this to your dealer and ask them to comment. Unlike most of us you have a big advantage in that your setup is stock in so far as anything that could affect the mount. They might need you to bring the car in, admittedly a PITA, but they'd be accountable to give you a definitive answer about what's causing it. It's just possible that yours is the first we've seen where the stock setup has started to fail but it might be the tip of the iceberg so the sooner the ball gets rolling the better.

 

[strengthrehab]

I got my stuff welded up today.

Now to get the stock mounts on until the newly designed BMRs come in.

I may also look into their shock tower brace that is in testing.

 

[shogun32]

I checked out the new 2023 Ford Mustang today at the dealer. It said Explorer on the front hood though.

As you can see Ford has learned nothing except to bandaid it in desperate hope it doesn't fail as fast. Given the kind of shocks an Explorer is likely to suffer I don't see this lasting either. Aren't these studs made of seriously brittle material? I think the sheetmetal is thicker, I'm eyeballing it at 2mm.

 

[fatbillybob]

look at all those stressrisers

 

[Brian@BMVK]

look at all those stressrisers

I dEsIgN aT FoMoCo

 

[shogun32]

I talked to some old hands and they said the hotrod guys weld thin panels like this using Mig as a series of spot-welds spaced widely. Do a series and then the next round spot between the previous pair. And again midway between those...

Or use a Lenco Mark II panel welder.

most HSLA (high strength low alloy) steels have directionally sensitive properties. Formability and impact strength can vary significantly when tested longitudinally and transversely to the grain. Bends that are parallel to the longitudinal grain are more likely to crack around the outer edge because it experiences tensile loads.

I think we have a case of an 'engineer' who slept thru his material science and structures class.

 

[fatbillybob]

Agree shogun. When you don't know science you weld a thicker plate! The chassis is high strength. I can tell trying to cut it. The pro s550 racers are silent as to how they reinforce this area. I think the easiest is 2 more rivnuts per side making support 4 places and welding extension plate to any aftermarket 2 hole shock mount copying the ridetech concept. The J&M mount is best beacause the bottom is flat makes for easy fab of more plate to weld. The vorschlag by contrast is scalloped and lightweight but then your fab is more complex.

My racecar is built. I'm lazy. Hopefully I get to this before I rip the holes out. For now I'm just going to race it and watch.

 

[BlownGP]

I checked out the new 2023 Ford Mustang today at the dealer. It said Explorer on the front hood though.

As you can see Ford has learned nothing except to bandaid it in desperate hope it doesn't fail as fast. Given the kind of shocks an Explorer is likely to suffer I don't see this lasting either. Aren't these studs made of seriously brittle material? I think the sheetmetal is thicker, I'm eyeballing it at 2mm.

Well, if that's the case. The S650 going to have even more problems in the rear.

 

[BlownGP]

Ford putting the joint in bending was the first mistake. There's a reason why most shocks have fasteners oriented in straight tension & compression or in shear (strut mounting).

I'm more of a visual learning. So are you saying since the bolt holes are on the humps per say instead of a flat even surface for both the holes that it makes them weaker?

 

[shogun32]

if the forces were *perfectly* parallel to the sheet-metal and the clamped area was big enough, the problem would be significantly reduced. But not only is the mounting surface not remotely 'flat' on the sheet-metal side, the articulating shock is thru the bolt acting on the nut rotating inward and outward trying to tear the metal across it's thickness. The metal is already brittle by nature and the focused edge of the nut flange is like a chisel. It's bloody obvious this was a STUPID design.

 

[Brian@BMVK]

I'm more of a visual learning. So are you saying since the bolt holes are on the humps per say instead of a flat even surface for both the holes that it makes them weaker?

It's less that than the bolts/mount surface being perpendicular to the shock axis, thus putting the entirely mount joint in bending.

 

[strengthrehab]

I went back to stock mounts yesterday. My L side mounting area looked fine, thankfully.

When BMR finalized their brace, I'll install that.

 

[CORNYOTE]

I’ve had Steeda and BMR mounts and this new Viking setup is by far my favorite. Simple, pulls the shock centerline closer to the frame rail for less stress and gives me the clearance to run a 325/50R15 rear.

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