Shock mount failure

[david brady]

Greg,



I don't think the axle tilt puts undo stress on the shock. If you

consider the steer axle in full droop on one side and full bump on

the other. The angle of the axle is roughly 5 deg to the horizon,

and this turns out to also be the angle of the shock.

(inverse sine of (8 inches / 96 inches)). The rubber bushings

in the shock can easily comply without transferring

excessive forces to the mounts. I'm sure Ridewell did this basic

calculation. If this were the cause then we'd be seeing similar

failures on the drive axles. The cause could be shocks that bottom

before bump stops (shocks too long), folks retracting their

HWH jacks w/o first airing up the suspension, folks raising the

front off the ground w/o first dumping air, or simply and inferior

Ridewell design. After year 2000 or so, I was informed by

the engineering staff at Ridewell that all their suspension systems

underwent finite element analysis and subsequent redesign;

consequently the LXi uses a different shock mount system than

the WB's. Could be that Ridewell addressed an inherent weakness.



David Brady

'02 LXi, NC







timvasqz wrote:

I think the crack was there from off-camber HWH jack parking in
the

past. looks like the temper of the weld proved a brittle spot that

under normal conditions would not have issue. Then the new shock

absorbed more bounce but reacted equally agressive causing much more

stress on the mount. I think the mount post should have less strength

and be a point that can bend at failure. the tripod gussettes are a

bad idea.



I think problems arise when the bus air bags are dropped to be

leveled but the spot is too off camber. the HWH push one side up

and tilt the axle too much. at that point raising the front is

effortless and and the 30 foot lever post all the stress on the

tucked tire.



If I was to repair that mount I would remove two bolts and make a

trapazoid shape cut and replace the plate with a butt weld then build

the post mount back no better than before.



If you lose an airline and must drive. there is a screw set in the

maxicam to turn off the parking brake. you can then plug the airline

and fold it over then tape it.

Greg ofTim&Greg

94ptca



..--- In "WanderlodgeForum%40yahoogroups.com",
"Don Bradner"

...> wrote:

>

> I'm the latest victim of a driver's side front shock mount
failure.

It took out the brake line when it went. I was not far from home on

the way back from Q, so I limped on in (I know, in retrospect it was

too dangerous, but I kept a lonnnng following distance!)

>

> I've used the local Detroit dealer in Arcata (Trinity Diesel) a

couple of times now for service, so I called them, and the service

manager said he would swing by for a look, no charge. He ended up

removing the shock and the air line, and said that he would come by

the next time he was this way with a new airline. A new shock will

have to be ordered (the top bent/caved in) and they will schedule an

appointment to get it welded after they have that. Shock was 17

months old.

>

>

> Don Bradner

> 90 PT40 "Blue Thunder"

> My location: www.bbirdmaps.com/user2.cfm?user=1

>

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