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Topic: Basement door, broken hinge bolt (Read 1874 times) previous topic - next topic

Re: Basement door, broken hinge bolt

Reply #25 –
I use plumbers synthetic grease on a  lot of parts.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Basement door, broken hinge bolt

Reply #26 –
OH, OH! Another Rube Goldberg suggestion.
Get a 1/4-20 socket head cap screw the same length under the head as the shoulder/stripper bolt. From someplace like Fastenal. The bolts are about 78 Rc.
Get a drill bushing same outside diameter as the bearing diameter of the shoulder/stripper bolt and the inside dia that will fit over the 1/4-20 bolt. Bushing length same as the round part of the shoulder/stripper bolt under the bolt head and to where the thread diameter starts. Economy headless drill bushing Company comes to mind as a source. Usually available from a bearing supply company.
Assemble bushing onto the bolt and now there isn't a "weak" spot where the threads end at the relief on the shoulder bolt
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Basement door, broken hinge bolt

Reply #27 –
If the bolts are tight there is no shear taking place at the smaller diameter. The shoulder part of the bolt would have a clamp load of over 2000 lbs. with a grade 5 bolt.

https://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Basement door, broken hinge bolt

Reply #28 –
Quote from: nitehawk –
OH, OH! Another Rube Goldberg suggestion.
Get a 1/4-20 socket head cap screw the same length under the head as the shoulder/stripper bolt. From someplace like Fastenal. The bolts are about 78 Rc.
Get a drill bushing same outside diameter as the bearing diameter of the shoulder/stripper bolt and the inside dia that will fit over the 1/4-20 bolt. Bushing length same as the round part of the shoulder/stripper bolt under the bolt head and to where the thread diameter starts. Economy headless drill bushing Company comes to mind as a source. Usually available from a bearing supply company.
Assemble bushing onto the bolt and now there isn't a "weak" spot where the threads end at the relief on the shoulder bolt
My guess is that if it had been built that way to begin with, this whole thread would never exist.

Re: Basement door, broken hinge bolt

Reply #29 –
Quote from: craneman –
If the bolts are tight there is no shear taking place at the smaller diameter. The shoulder part of the bolt would have a clamp load of over 2000 lbs. with a grade 5 bolt.

https://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf

Having no mechanical engineering background to speak of I'll try to parse what you're saying:

If the bolts are tight, there's no slippage between the 2 pivoting arms at the pivot point, and therefore no shear force.

I guess my reply to that would be that the holes in the arms admit a 5/16" bolt with no enlargement required.  If that's the case, then since the section of the bolt that occupies that space where the arms pivot is necked down - below 1/4" by the depth of the thread (making it what, 3/16"?) then the potential for slippage in that space is always present - and any slippage between the arms at the pivot point would exert a shear force on the bolt at that point.  How's that?  So does it really make sense to have the bolt undersized at that point where the arms pivot, or would it have been better to have a sleeve there and let the bolt turn free inside it?  I think it's just a poor design.  But the point about keeping the bolt tight at all times is well taken.  I'll just add it to my ever growing list of things to do periodically.

Re: Basement door, broken hinge bolt

Reply #30 –
Quote from: RT_Geezer –
Having no mechanical engineering background to speak of I'll try to parse what you're saying:

If the bolts are tight, there's no slippage between the 2 pivoting arms at the pivot point, and therefore no shear force.

I guess my reply to that would be that the holes in the arms admit a 5/16" bolt with no enlargement required.  If that's the case, then since the section of the bolt that occupies that space where the arms pivot is necked down - below 1/4" by the depth of the thread (making it what, 3/16"?) then the potential for slippage in that space is always present - and any slippage between the arms at the pivot point would exert a shear force on the bolt at that point.  How's that?  So does it really make sense to have the bolt undersized at that point where the arms pivot, or would it have been better to have a sleeve there and let the bolt turn free inside it?  I think it's just a poor design.  But the point about keeping the bolt tight at all times is well taken.  I'll just add it to my ever growing list of things to do periodically.

Where the shoulder of the bolt contacts metal the force of a 5/16-18 nut being tightened is over 2000 lbs. clamping against the metal. There is no movement at that contact point therefore no shear. If the nut gets loose the force is all shear since no clamping force is in effect. All of the movement is along the shoulder part of the bolt.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Basement door, broken hinge bolt

Reply #31 –
Quote from: craneman –
Where the shoulder of the bolt contacts metal the force of a 5/16-18 nut being tightened is over 2000 lbs. clamping against the metal. There is no movement at that contact point therefore no shear. If the nut gets loose the force is all shear since no clamping force is in effect. All of the movement is along the shoulder part of the bolt.

Maybe we're talking about different locations.  In my case, there is movement - pivoting movement between the 2 arms being held together at that point.  And where that pivot movement takes place there is a gap of 1/8" on the diameter there between the holes in the arms and the necked-down section of bolt (a 3/16" section of bolt inside holes in 2 arms that are at least 5/16"). There is nothing but clamping force to keep the arms from slipping in the direction of shear.  Regardless how tight the nylon threaded nut is, some slippage in the direction of shear due to the pivoting motion is inevitable - there is nothing to prevent that (whereas a lubricated sleeve - or bearings - would prevent it).  We must be talking about 2 different locations.  I just had mine apart - and I'm referring to the location where my bolt broke.  Given the additional weight and leverage of the wide bay doors found on the 40' coaches, a better mechanical solution at the pivot points would prevent the bolt from breaking.
I think my words are failing here, and we all have better things to do, so this will be my last comment.

Re: Basement door, broken hinge bolt

Reply #32 –
Here are the pictures of my bay door hinges.

1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Basement door, broken hinge bolt

Reply #33 –
Quote from: craneman –
Here are the pictures of my bay door hinges.

Chuck,
As you've already seen, here are  mine ... I'm glad you pursued this, as even though we both have '99 40' U320s, the pantographic door hinge assemblies are different - yours have nylon washers, and mine do not.  Whether they did have the washers when the coach was built is anyone's guess.  I'll see if I can get hold of some and retrofit - making sure the bolt shoulders are the correct length to accommodate.
Thanks very much!
Rich