74Weld Bronco Portals now available!

[ScLeCo]

Chad had said new brackets should be mailed in about 3 weeks (a week ago). Does this sound about like y'alls time frame?

I spoke with Quinn on Friday and he said they would be shipping sometime this week, but who knows.

I do like the inset o-ring on the new fill plugs though. No more popping out like a blister.

I don't I still got a little bit of leakage. Not much but enough that you could see it when things got dusty. I went back to crush washers and bone dry after that.

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[SierraBronco]

I do like the inset o-ring on the new fill plugs though. No more popping out like a blister.

Almost like that is how they should have been done from the beginning. I'll forgive missing that one though. Taking six weeks to send me a fix to a problem that they already knew existed and only said anything because I called them? That's not as cool. Just like the leaking stub shaft seals. They know it is a problem. I shouldn't have to call them about it once I see it. If a problem is found on your $21,000 accessory then at a minimum you could email your customers and tell them there is a fix. Send it if they want it.

 

[SierraBronco]

I spoke with Quinn on Friday and he said they would be shipping sometime this week, but who knows.

I don't I still got a little bit of leakage. Not much but enough that you could see it when things got dusty. I went back to crush washers and bone dry after that.

Those crush washers are legit. Zero leaks since they have been installed.

 

[Snacktime]

I would think they'll be supplying new bolts and washers with the brackets, especially with what the old bolts have been subjected to, but I couldn't tell you for certain. The only thing I "know" is based on an email from them saying the brackets are being redesigned to accommodate the dowels. No clue what the final design will be.

But now with what was discovered over the weekend, I would be even more curious about the threads inside the portals. According to the internet, minimum thread engagement with aluminum threads is 2x the diameter. The 1.5" bolts that were installed by 74W into my boxes are 35% short of that minimum. Even the 1.75" bolts are 11% short with the split washers and flat washers they originally used. It is better when using the nordlocks, but still falls roughly 2% short of minimum engagement requirements as per "the internet" specifications. And how does the shear forces and fatigue they've experienced affect all that?

You need thread depth to achieve full strength, less thread depth just means the treads will fail before the bolt. Not something to worry about unless your bolts are stripping out.

At this point we don't know if bolt size is based on thread strength or those cap bolt/washer head area. Back engineering the problem I say both.

Engineering mumbo jumbo here https://mechanicalc.com/reference/bolted-joint-analysis and note that you have damage in the pressure cone zone in diagram 1.

Several things you can do! more bolts! bigger bolts! longer bolts!

 

[SierraBronco]

Okay. So it's not just me. I'm quite confident that the bolts used to initially hold the brackets on were all 1.5" but - I threw them away when 74Weld brought more bolts to Sand Hollow. Those new bolts were all 1.5" for sure. The latest ones they overnighted to me (after they got back from sand hollow. And missing the overnight deadline. Not talking shit, just stating facts. Credit to 74Weld for paying for overnight even though they missed overnight dropoff deadline) with the new but still wrong brackets are 1.75" inches for the bottom two holes. We were watching Down Periscope when randomly, I was hit with the need to verify thread engagement. Must've been some subliminal messaging in the movie. Maybe it was the bolts shooting out of the hull when they were hiding from sonar in the cavitation of the tanker. Can't be certain.

Their bracket is .6615" wide
The spacer is .255" wide
Split ring and washer .166" wide (as best I could tell. Didn't run them between two nuts or anything, just measured opposite the split)
Nordlocks are .0970" wide

The counterbore bolt isn't an issue when it comes to thread engagement as the counterbore is something like .534" deep.

But for the other two bolts, we get:
1.5" bolt
- .6615" bracket
- .166" split ring and washer (.0970 Nordlock
- .255" spacer/shim
= .4175" thread engagement into aluminum threads with a .375" diameter bolt 1.5" long with split rings, or .4865" of thread engagement with nordlocks.

This last time around they did supply me with longer bolts, as stated above.
1.75" bolt
- .6615" bracket
- .166" split ring and washer (.0970 Nordlock
- .255" spacer/shim
=.6675" of thread engagement with split rings. Or .7365" with nordlocks.

Can any of our smart guys please confirm this very complicated math and how much thread engagement one would want with aluminum threads and .375" bolts?

This does make me curious how their new brackets will be designed for the OEM caliper mounts. Assuming they widen the whole bracket by the spacer amount to accommodate the dowel, the OEM bolts won't be long enough. So will they supply new bolts that are longer or just machine down those mounting locations to their original bracket width?

 

[SierraBronco]

You need thread depth to achieve full strength, less thread depth just means the treads will fail before the bolt. Not something to worry about unless your bolts are stripping out.

At this point we don't know if bolt size is based on thread strength or those cap bolt/washer head area. Back engineering the problem I say both.

Engineering mumbo jumbo here https://mechanicalc.com/reference/bolted-joint-analysis and note that you have damage in the pressure cone zone in diagram 1.

Several things you can do! more bolts! bigger bolts! longer bolts!

This is awesome.

So far the bolt threads have all seemed fine. There was the time before sand hollow where the bracket that they told me was fine caused the bolt to screw in with an oval-spiral shape to it, but seems to thread in straight without it. Still seems concerning, but that was on the counterbored bolt which has plenty of thread depth. No spiral oval spinning with their new/old brackets.

 

[Razorback]

do you guys use crush washers on the drain plugs as well? link?

 

[Snacktime]

This is awesome.

So far the bolt threads have all seemed fine. There was the time before sand hollow where the bracket that they told me was fine caused the bolt to screw in with an oval-spiral shape to it, but seems to thread in straight without it. Still seems concerning, but that was on the counterbored bolt which has plenty of thread depth. No spiral oval spinning with their new/old brackets.

Then you need more bolt head area to spread out the pressure. Also need to have more force (more bolts) sandwiching the brackets to prevent movement.

 

[SierraBronco]

do you guys use crush washers on the drain plugs as well? link?

I haven't had any problems with my drain plugs, even before using teflon. My magnets still feel tight too. But after getting the go-ahead from 74w to use the teflon I went ahead and threw that on as a precaution.

 

[SierraBronco]

Then you need more bolt head area to spread out the pressure. Also need to have more force (more bolts) sandwiching the brackets to prevent movement.

The nordlocks do give more area as the old washers they provided were some slick little units that seem to be designed to fit within the counterbore. They are the same diameter as the bolt cap. But, you can only use the nordlocks on 2/3 bolts.

 

[Bikeric]

I would think they'll be supplying new bolts and washers with the brackets, especially with what the old bolts have been subjected to, but I couldn't tell you for certain. The only thing I "know" is based on an email from them saying the brackets are being redesigned to accommodate the dowels. No clue what the final design will be.

But now with what was discovered over the weekend, I would be even more curious about the threads inside the portals. According to the internet, minimum thread engagement with aluminum threads is 2x the diameter. The 1.5" bolts that were installed by 74W into my boxes are 35% short of that minimum. Even the 1.75" bolts are 11% short with the split washers and flat washers they originally used. It is better when using the nordlocks, but still falls roughly 2% short of minimum engagement requirements as per "the internet" specifications. And how does the shear forces and fatigue they've experienced affect all that?

Yes, you need thread engagement into aluminum of 2x the bolt diameter (so 20mm in this instance). The torque spec for Grade 12.9 M10x1.5 should be 45 ft-lb when using a flat washer. Any split washer should get thrown in the trash. Even though I couldn't recommend using Nordlock's I know some people will, and if you do you need to torque the bolts to 60 ft-lb to account for the under-head friction.

 

[SierraBronco]

Yes, you need thread engagement into aluminum of 2x the bolt diameter (so 20mm in this instance). The torque spec for Grade 12.9 M10x1.5 should be 45 ft-lb when using a flat washer. Any split washer should get thrown in the trash. Even though I couldn't recommend using Nordlock's I know some people will, and if you do you need to torque the bolts to 60 ft-lb to account for the under-head friction.

Our latest directions from 74W are to use the nordlocks and torque to 36 lbs/ft (up from initial 28, then 30) while using a 4" long 5/16" hex bit. (standard hex will not work. Needs to be ball end to clear hub flange but the directions do not specify this)

 

[5GENIDN]

I would like to not lose my life. It's important to me for...living...

Understand... But even with catastrophic failure, The loss of your life is not a very high probability. YES that would be worse than anything they stand to lose... But my point is more to the financial question. It could total your vehicle. And on their side they could crash the entire company with law suits.... So technically you have more to lose but... I think you understand what I am trying to say. It is very much to their benefit to make this right. My guess is that they will come through.

 

[SierraBronco]

You need thread depth to achieve full strength, less thread depth just means the treads will fail before the bolt. Not something to worry about unless your bolts are stripping out.

At this point we don't know if bolt size is based on thread strength or those cap bolt/washer head area. Back engineering the problem I say both.

Engineering mumbo jumbo here https://mechanicalc.com/reference/bolted-joint-analysis and note that you have damage in the pressure cone zone in diagram 1.

Several things you can do! more bolts! bigger bolts! longer bolts!

This is interesting to see written out:

Another way to express the total tensile force on the bolt is:


The shear force on the bolt is equal to the shear load applied to the joint:

Fb.s = Fs.app
A bending moment could exist in the bolt if there is a gap between the plates (e.g., due to a gasket) or if there are long spacers used in the joint:

Mb = Fb.s a / 2
where a is the moment arm. More discussion on the bending moment on the bolt is given in the Appendix.

We have those big spacers between the bracket and portal box. Something else that was noticed is that without the spacer but with the dowel in place, the dowel acts as a pivot, so the bracket rocks back and forth like a teetertotter. The dowel is fairly "centered" in the bracket as far as end to end is concerned, but the pivot action means that when you tighten the bolt on one end, there is now a .087" gap on the other end. Can't imagine it would be good to just crank that effer down.

Granted, based on their email they knew the dowels wouldn't work and didn't use them, so maybe the holes are just there for practice and it wasn't important that they lined up without the spacer.

 

[Bikeric]

Our latest directions from 74W are to use the nordlocks and torque to 36 lbs/ft (up from initial 28, then 30) while using a 4" long 5/16" hex bit. (standard hex will not work. Needs to be ball end to clear hub flange but the directions do not specify this)

Not if they're sending you Grade 12.9 bolts. They must be worried about stripping the aluminum threads (which might very well happen if the aluminum quality is low).

Bolted Joints that need to withstand vibration should have bolts tensioned to at least 60% of the bolts tensile strength. That is how you should spec the torque, and it needs to be 45 ft-lb to achieve the ~10,000lb of tension in a Grade 12.9. M10x1.5 is a thread size I know very intimately and performed months worth of testing on (threading into Aluminum, no less).

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