Home » Public Forums » GMCnet » [GMCnet] Shoddy Preventative Maintenance
| [GMCnet] Shoddy Preventative Maintenance [message #326004] |
Tue, 14 November 2017 15:30  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
I've lately been thinking that I should examine my rear suspension. I
Installed one of the first production run of the Manny Brake system. Aside
from having re-tightened the reaction arms' pivot block securing bolt a few
times during the first 1000 miles, I really haven't looked at the system
again. That includes my trip to the west coast in 2013, Kerry Pinkerton's
and my trip to Pueblo and Rapid City in 2015, and many other trips --
undoubtedly 20,000+ miles, 'tho' I haven't checked my records.
So, yesterday, about 246/254ths of the way home from the FL panhandle, we
heard a loud scraping noise from the rear of the coach when I applied the
brakes. After a couple of episodes, 3 miles from home, I pulled into a
large used car lot and sought out the source. Here's what I found at the
right rear bogie:
https://drive.google.com/open?id=0B3XquSIYjDleNVZROTYxXzBSeXBBaWlHd0tvZEluaTFaR3dB
Ooops, wrong link! Try this:
https://drive.google.com/open?id=1bm24_y8ugQZ6fbZWU8gIkBf5DSrH-cWYbQ
Not quite as catastrophic as the first one! Yep, the securing bolt for
the reaction arm pivot block loosened, allowing the block to twist 90* and
come out of the bogie. That means that the reaction arms acted only on
each other. Braking force became dependent upon whatever limits rotation
of the torque boxes whch support the brake calipers. I haven't removed
anything yet to check for damage, but I really don't expect any. I'm
confident that Manny anticipated similar events. There seemed to be no
effect on normal braking, but I barely used them after the noise began.
I'll report any further findings.
Remember to do as I SAY about preventative maintenance -- NOT as I DO. :-)
Ken H.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326006 is a reply to message #326004] |
Tue, 14 November 2017 16:58  |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
|
Senior Member |
|
|
WHen I had a similar experience, my 'Tee nut' was long gone. Manny sent me more and I put a longer bolt and a jamb nut on top of the Tee Nut. Futher, I put locktite on everything and applied considerable force on the bolt and the jamb nut.
After some thinking, I decided that the problem was that the area where the nut flanges sit is not flat, square or even smooth. This was allowing the force of braking to move the Tee nut and eventually loosen. So I took everything off, annealed a piece of 1/16" aluminum by sooting it up with an acetylene flame and then burning the soot off with a neutral flame on my gas torch. This put the aluminum in a 'dead soft' state. When I reassembled everything, I put an extra pull on everything. EIther the jamb nut, locktite, or the aluminum must have done the trick because I put about 15k miles on it with no further problem.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326010 is a reply to message #326006] |
Tue, 14 November 2017 20:19 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
I remember you making that suggestion back when we first installed the
Manny Brakes. I never did it and thought I was getting away without it.
Now, I suspect that the mis-matched surfaces are the root cause of the
problem. The bolt doesn't look as if it's backed out any, so the surfaces
must have worn enough to allow the nut plate to rotate. I'll try to get a
look at the interior of the bogie (mirror or endoscope or digit) to see if
it's been smoothed by the nut plate moving about. And check the other
side, which should be showing similar wear.
Ken H.
On Tue, Nov 14, 2017 at 5:58 PM, Kerry Pinkerton
wrote:
> WHen I had a similar experience, my 'Tee nut' was long gone. Manny sent
> me more and I put a longer bolt and a jamb nut on top of the Tee Nut.
> Futher, I put locktite on everything and applied considerable force on the
> bolt and the jamb nut.
>
> After some thinking, I decided that the problem was that the area where
> the nut flanges sit is not flat, square or even smooth. This was allowing
> the
> force of braking to move the Tee nut and eventually loosen. So I took
> everything off, annealed a piece of 1/16" aluminum by sooting it up with an
> acetylene flame and then burning the soot off with a neutral flame on my
> gas torch. This put the aluminum in a 'dead soft' state. When I
> reassembled
> everything, I put an extra pull on everything. EIther the jamb nut,
> locktite, or the aluminum must have done the trick because I put about 15k
> miles
> on it with no further problem.
> --
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326013 is a reply to message #326004] |
Tue, 14 November 2017 21:16 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
That'll make you swallow your chew! I've the other system, which uses a heavy piece of channel on the bottom, and above the slot a plate with a bolt welded to it. That it's (mine) a drum system makes no difference, you're applying the same forces to the torque box and hence the pivot anchor. They're coming from the backing plate instead of a caliper is all. And while I don't think the design I have is capable of failing that way, checking the center assembly for tightness and >any< signs of movement just went to the top of tomorrow's to-do list.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326017 is a reply to message #326004] |
Tue, 14 November 2017 23:00 |
78 Barbi
Messages: 80
Registered: August 2004
Location: Tiverton, Ontario , Canad...
Karma: -1
|
Member |
|
|
Ken Henderson writes: Yep, the securing bolt for
the reaction arm pivot block loosened, allowing the block to twist 90* and
come out of the bogie.
Thanks for the " heads up" Ken, the chap that makes the SS water tanks in Alberta also had this happen . The inner part of the bogie box is not a machined surface and as such
is not perfectly matching the profile of the "Tee nut" , this coupled with the forces applied by the reaction arms during braking causes the " Tee nut" to move slightly and eventually
loosening and ultimately coming out of the bogie box.
I'll send out a bulletin to the 5 folks that have proceeded with the Lambke & Kelsey Hayes upgrade on the Manny reaction arm system since all the anchor points are onto the bogie
box with the exception of one , that one was a transition from the torque box directly onto a pair of the 1-1/4" Caspro sway bars. Kerry; like your idea of the annealed aluminum plate,
that solution along with loctight should do the trick.
Cheers......Albert Branscombe
Tiverton, ON
78 Barbi, 23' Birchaven
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326027 is a reply to message #326004] |
Wed, 15 November 2017 11:58 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
I took a look at mine (Tom Pryor design from Applied) and I'm not worried. The pivot anchor is cut to match the bottom of the bogie pivot mount, and the plate which holds the nut for the through bolt is bigger in each dimension than the slot - it cannot pass back through with the bolt screwed into it.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
| Re: [GMCnet] Shoddy Preventative Maintenance [message #326043 is a reply to message #326027] |
Wed, 15 November 2017 17:43 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Today I reassembled the reaction arms. I wasn't able to do a visual
examination inside the bogie, but it felt quite smooth now. Perhaps the
irregularities were self-corrected . In view of that, and the fact that
I've been running for 20K+ miles with no previous problem, I didn't follow
Kerry's example. I did turn about 0.100" off of the spacer's thru-bogie
extension to be sure the two blocks don't bottom out. I can now see
clearance between the two when the bolt is tightened to 175 ft-lb or so.
When I tested the bolt on the other side, that torque moved the bolt about
10* -- it was TIGHT. I have not yet disassembled that side to ensure that
the blocks are not bottomed out; I will soon.
No other part of the Manny Brakes at either wheel showed any damage nor
abnormality.
I'll try harder to comply with my own advice in the future.
Ken H.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
Goto Forum:
Current Time: Fri Apr 19 20:56:46 CDT 2024
Total time taken to generate the page: 0.00873 seconds
|
GMCforum
Search
Help
Register
Login
Home
