Author Topic: STRIPPED NEWMANS CHEAP SHORT BOLTS (Read 1217 times)

mooseman · « **on:** May 27, 2015, 10:18:15 PM »

Really really pi$$ed at the guy who cheaped out on the bolts in my Newman MZX frames.
Why in the hell they used a 1 inch long bolt that only allows 7/16 of an inch engagement into aluminum threads blows my mind.

A simple change to a 1-1/2 inch long bolt could have easily eliminated this issue..........how much more could a bolt that is 1/2 in longer cost especially when you are buying them by the 1000's.

30% of the frames that I bought new direct from Stretch Devices have at least 1 stripped roller end

.
the picture attached shows the whole story
Just FYI we torque the bolts to 38 ft-lbs with a quality torque wrench
mooseman

jsheridan · « **Reply #1 on:** May 27, 2015, 10:53:32 PM »

Ive been torquing rollers for 25 years and I have never stripped an end bolt, and thats even with the short black oxide bolts you have.

45 ft lbs for MZX
55 ft lbs for M3

The fact that you have multiple stripped bolts tells me something is up with your tensioning.

Are you sure youre using the correct setting on your wrench? I

Gotta add.. if you change the bolts, you bottom out the threads as the end cap is sealed.
also.. SS bolts will seize when torqued into aluminum, youll need to spread copper anti cease on tue threads before you thread them in.

mooseman · « **Reply #2 on:** May 27, 2015, 10:59:21 PM »

Absolutely positive on the wrench setting kind of an old motor head so I am not new to this kind of thing.

the frames I have stripped out are the "light weight" silver jobs not the heavier blue jobs. We have both the blue frames physically out weigh the silver frames by at least 2x, never stripped one of those (yet) just those light weight jobs.
mooseman

jsheridan · « **Reply #3 on:** May 27, 2015, 11:03:50 PM »

Ill get a hold of george and have him get in contact with you to discuss a resolution.

mooseman · « **Reply #4 on:** May 27, 2015, 11:13:54 PM »

That will be fine but I am not looking to any coverage from Stretch Devices the frames were new to me but are no longer new by a long shot.
My point and disappointment is it is pretty mechanically unsound to have just 7/16 penetration of a steel bolt into an aluminum thread.
If the bolt were1/2 inch longer initially the threads in the aluminum, I am sure, would have held up OK.
the cost differential of a 1/2 inch longer bolt is dirt , it just makes no sense

mooseman

Itsa Little CrOoked · « **Reply #5 on:** May 27, 2015, 11:26:07 PM »

Call me tomorrow. The nuts are replacable.

Oh, not by mere mortals. But YOU can do it, I promise.

mooseman · « **Reply #6 on:** May 27, 2015, 11:33:29 PM »

hey buddy, I am guessing there will be some heat involved...........I am very interested...I will buzz you on Thursday.
mooseman

Screen Dan · « **Reply #7 on:** May 29, 2015, 07:38:08 AM »

My guys maintain an inventory of ~600 23x31 MZX-UL and we have this problem as well. The age of the frame doesn't seem to matter either. We only torque ours to 35ft/lbs. I wouldn't say that 1/3rd of ours get stripped, probably about 1/8th. We have two parts piles...stripped and non-stripped. We build frames out of the non-stripped and then we re-tap the stripped pile. The only ones we toss are when the bolt is stripped and can't be removed.

The real pisser is when a 32x48 M6 tube gets stripped beyond repair. We only have about 48 of those so that frame is effectively shot since we don't have a big parts pile of those. Thankfully it's only happened once in the past 3 years.

Any tips on how to avoid this would be awesome.

Itsa Little CrOoked · « **Reply #8 on:** May 29, 2015, 08:49:25 AM »

I've not seen any MZX's with aluminum threads, but Mr. Moosey said his are.

I suggested to him yesterday, that he should pull those endcaps out and epoxy a Stainless Steel nut on the inside of the endcap. It might require a nod to the Art Of Barnyard Physics to provide a good surface. Mine are different, I guess.

The ones I've repaired just have a Stainless Steel nut on the inside which are a cinch to replace. Re-epoxy the endcap in place and you're up and running.

I remove mine with a propane torch (warm, not HOTT) to heat up the epoxy and pull them out with a slide hammer (Body Hammer, Dent Puller etc.) which has a bolt welded on to the "stinger". A little heat, and the epoxy gives up fairly easily. The hardest part is sourcing Stainless Steel bolts which aren't threaded all the way. The smooth "shoulder" provides a sealing surface for the O'rings or plastic Hoomahickey...whichever you have.

But these frames have undergone a lot of changes over the years. YMMV.

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