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Re: lubricating trunnions

To: british-cars@Alliant.COM
Subject: Re: lubricating trunnions
From: Michael Sands <mit-eddie!apple.com!sands@EDDIE.MIT.EDU>
Date: Mon, 5 Mar 90 13:12:40 -0800
I have found out more since I started this and it may help muddy the 
waters further.

The threads on the trunnion are threaded oposite for left and right.
There is a groove cut through the threads vertically that allows the 
lubrication to pass from the grease nipple in the vertical link
through the brearing.  What appears to be a dust cap where the trunnion
meets the vertical link has a strange profile as does the end of the
trunnion where it meets the seal.

                        -----------
                        \         /
                         \-     -/
                         /       \
                         --------
                 
                        /--------\
                       /          \
                       -         -
                        I       I

I also looked up the proper section in the Lotus Super Seven
book concerning the adjustment and lubrication of the trunnion.
It says to tighten it completely and to "unscrew it to working
height".  It also says to lubricate it with 90 wt gear oil.

I finished the installation of my suspension this weekend in
a marathon effort supported by my daughter and wife.  I set
the alignment with my nifty new tool from Halibrand.  The goal
was one degree negative camber and about 2.5 castor.  By the
time I had taken apart both suspensions five times for adjustment
I was wishing for the good old naive days before with no adjustment
available.  The only hitch was getting the castor down.  With
the rod ends screwed all the way in it now sits at 3.5 or so.

In my discussions with Jim and reading Phun's book I am uncertain
if this is good or bad.  I will try it and see how it feels on the
next sunny day.  Puhn suggests that light cars with big tires
maintain large amount of castor and Smith seems to confirm.  I 
don't understand enough of the theory to make a call myself.  The
table Puhn has shows Triumphs in the 3.5 and 4.0 degree range.

All that is left is to have my daughter and wife paint the nuts
with nail polish so I can see if any are not tight.  You have
to find something for the eight year old to do to make sure she
turns into the daughter of a SOL'er.

Michael


PS  I found a good way to pump the trunnion with 90 wt.  Unscrew
the body of the grease gun and hold the lever and head unit
upside down.  Carefully fill the small cup with 90 weight, and
carefully, without shaking, pump it into the trunnion.  Requires 
the skill and steady hand of a surgeon, but then most operations
on Brithish cars do.



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