[TR] Broken rear stud for rocker arm assembly

Chris Simo ccsimonsen at gmail.com
Thu May 10 06:11:28 MDT 2012


Ok - recap of last update - had a nut broken off the water pump pulley; a
loose downpipe/manifold connection; broken rocker stud;  and created some
self-induced challenges along the way.  Swapped out  with an old water pump
and still had metallic noises from engine.  I'm glad I pulled the head as I
was afraid something inside number 4 had caused the stud to break.

I tried to do some root cause analysis before I reassembled - so I cleaned
everything and really gave things a good study.

1.  Rocker stud washers have become a bit domed and are in general a bit
rough - I bought new ones from one of the big three when I rebuilt the
engine and apparently got unhardened washers. - They are reasonably thicker
than standard washers but  deformed nonetheless.  So my best theory here is
they deformed, reduced the torque on the nuts to zero or less and then the
valve train hammered away on the stud until it failed. - Rocker arms do not
seem to have any noticeable wear - so I'm leaving them as is.
2. Exhaust manifold to headpipe - No idea - the nut was down about 1/4 inch
- but not easy to loosen or tighten - maybe I missed tightening this
one.....
3. Water pump nut - I feel this is my bad - I felt the pump pulley was a
bit too easy to slide on the shaft a few months ago and even got the
locktite product that Randall uses to fill in the gaps - but did not get
around to putting it on.... so I deserve this one - Bad thing is - it took
out the pump and the pulley. Much more expensive than the locktite bearing
product.  My spare used water pump felt good in my hand and I greased it up
- but in removing the belt - I see that it has some play in the bearings
and that is likely the reason for the  continued racket in the engine;  The
noise from the free pulley bouncing around water pump one - and the noise
from worn bearings in water pump two are quite similar.
4. I reused my payen head gasket - not sure how long I'll leave it on - but
wanted to move along with my troubleshooting - I sprayed both sides with a
couple coats of the copper spray - some folks swear by it others think it's
trouble - I've used it in the past.  I've reused head gaskets twice before
due to financial constraints -   once on the TR2 -  back in 1976 - it's the
one that is still on it.  and once on the TR4 - it was retired after
several thousand miles when I rebuilt the engine.  Since I'm not strapped
for cash at this time - I plan to pull the head and do it right and figure
that with 2 behind me my luck has run out.

Head is back on and everything is buttoned up.  Left the water pump on the
car - but disconnected the belt.  Filled the radiator and used the hose to
force water through the head as I was going to start it without the belt on
to see if noise was gone.   Started right up - no noise - shut down.

Lessons relearned - go back and check those fasteners after the engine is
broken in; Don't run a water pump without a good fit between shaft and
pulley; Don't use an unrestrained hose when adding fluif to the
transmission - or rear.

Now I'm waiting for my parts.  Thanks for those that replied with advice
and encouragement.

Chris

54 TR2 - getting a new wiring harness this weekend
63 TR4 - Soon to be daily driver again
69 TR6 - needing welding and attention


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