Justin & list,
I was absent from the list yesterday and missed being able to have some
input on the shock fluid topic. As some may know we rebuild lever shox, but
this is not meant as a commercial post. Perhaps my experience of having
seen and taken apart probably more Sprite front shox than others on the
list may help.
First, the original Armstrong shock absorber fluid seems equivalent to a
20 wt fork oil (or hydraulic "jack" oil). This is from my observations, not
technical treatises. An original Healey 100-4 owner's manual notes that
should it be necessary to replace/top-up the shock fluid and the proper
Armstrong oil is not available, then use a 20 wt hydraulic OR engine oil.
(brand names available though NLA)
Sprite fronts (5925L/R) are the most difficult Armstrong shock we
rebuild
because of the quality of the units we get to rebuild (cores). Failures
unique to 5925s are 1) loose arm on the shaft, 2) piston bore ridge, 3)
broken connecting rod 4) blown poppet valve 5) stripped trunion screw 6)
leaking body casting.
1 through 4 can be directly attributable to incorrect fluid or low fluid.
Too high a viscosity _can_ "stiffen" the shock beyond the tolerances of the
mechanical components. The arm and the internal rocker arm are affixed to
the shaft by splines which we see often stripped and invariably the shock
has been "beefed-up" with heavy oil. Broken connecting rods and blown
poppet valves occur for the same reasons. Bore ridges usually occur with
fluid too thin, contaminated w/ dirt, low fluid levels, or low lubricosity
(?). Rare is the core that doesn't have at least one of these conditions.
The tear down guys um.... "dislike" them. Takes twice as long.
Justin, this is probably a lot more than you wanted to know, sorry. In
short DO NOT USE HEAVY OIL IN SHOX. The proper way to get a stiffer ride
(if the shock is working properly) is to adjust the valves, but that will
have to wait for another day.
At 07:11 PM 12/16/98 +0000, Justin Cook wrote:
>Just what is this "shock absorber fluid"? I assume it comes from the
>same place as "turn signal fluid." Can I put 90 weight oil in these
>shocks or what?
>
BTW, "turn signal fluid" is actually a refrigerant made by Joe Lucas that
turns to vapor when exposed to the atmosphere.... hence the "smoke has
leaked out" when the signals cease to work.
Peter Caldwell
1 very rough Innocenti
(the Sprite with an accent)
among other LBCs and 4WDBCs
Contact for: The Columbia County Bonspiel
Curling on 13 sheets @ 5 clubs in WI
Feb 5 - 7 1999
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