Paul,
1) The crank pulley (harmonic balancer) is a friction fit (no capscrew).
Standard puller should remove (but be sure and use the tapped holes in the
pulley).
2) A small bracket goes around the middle of the tube (or thereabouts) and
bolts to the block (shares an oil pan bolt or uses a block boss). The insert
into the block is a friction fit (very little friction I might add).
3) Yes. Use the harmonic balancer to centralize the timing cover (install the
harmonic balancer prior to final tightening of the timing cover bolts). This
is a very important step.
4) I'm not sure what you mean by "anything else", but the timing cover (and
balancer), and oil pan (among other ancillary items connected to such) will
need to be removed including the front plate prior to messing with the front
bearing cap. I suppose it might not hurt to install the front plate, but it
seems unnecessary (and I've never done it that way). Now would be a good time
to tap the front bearing cap so that the two reversing bolts can be installed
from the cover side (that way you can remove the timing cover without removing
the oil pan - email back if you don't understand this).
5) The main caps use bolts. Carefully measure the bolts for stretch. A
thorough rebuild includes replacement of the bolt inserts and nuts on the
connecting rods (among other things). A minimal rebuild would reuse all said
parts, once again, you can measure the bolt inserts for stretch. See your
favorite machinist for the specs.
6) See Bob Adler's tech article on www.chevytrucks.org. I think it addresses
it. If it doesn't, the answer is yes (and no depending on who you talk to).
If you're going to plastigage everything, it would be easy to lift the crank
out to ensure a proper fit for the seal.
7) Yes, 235 timing gears are fiber (among other materials), however a cherry
timing gear (i.e. very little visual wear) that has been soaking in oil for 50
years (or however many) can have a tendency to shear, i.e. the fiber weakens
with time. I recommend you replace the gear if you do not know the history.
8) Yes, the seal can be installed with the socket *given* you properly support
the back of the cover and use the right size socket.
9) Good question. For the best fit, the head and manifold should be machined
to the specified flatness. Those cast iron products have a tendency to warp
with usage and that could be what happened in your case. Check both with a
machining straight edge. I've used a Permatex product made for exhaust
manifolds (copper color) if going the minimal route (however, with limited
success).
10) Dress up the oil pump prior to reassembly (i.e. check for wear). It's a
good time now. Also visually check the lower end of the cylinder walls for
early problem signs. It seems a shame to spend all this time if there are
piston problems in the works.
Good luck!
Allen in Seattle
Inline #2235
'50 3100
>>> <Hudson29@aol.com> 07/19/99 03:58PM >>>
This weekend I got a little time to clean and do a some work on a '59
235 that is to go into my '51 3600 someday. The motor was supposed to be a
good running unit, and maybe internally, it will prove to be in sound shape,
but the items I can see on the outside, however, do not inspire confidence!
In view of some of the "teenage" type work in the areas so far
visible, it seems like a good idea to roll the motor over on it's stand and
open up the bottom end for inspection. A little time with the factory shop
manual brought up as many questions as it answered. Here are a few of them:
1. What holds the crank pulley on? I found a hole in the nose of the
crank, but not the expected big capscrew. Do you need the special GM
tool to remove it?
2. What holds the "Road Draft Tube" in place? I could find no fixings
of any variety.
3. The book claims that a special tool is required to centralize the
timing cover hole around the crankshaft. Is there a workaround for those
of us lacking that tool?
4. Can the bearing caps be removed for plastigageing without
disturbing anything else? The manual warns somewhat cryptically that
something from the front mounting plate is attached to the front
bearing cap and must be tightened first!
5. Can the main and rod nuts be reused, or should they be replaced?
6. I understand that if my motor has the wick type of rear main seal
the crank must be removed to remove the old upper seal. Should the seal
prove to be of the more modern lipped design, can I sneak the upper
portion out V-8 fashion with a brass punch?
7. One of the 216 timing gears was fiber. Is this also the same with
the 235, and if so will any weakness or damage be obvious?
8. Can I drive the front main seal into the timing cover with a
socket or should I begin the search for a proper seal installer?
9. There is some evidence of exhaust leakage between the head and the
exhaust manifold. Are the stock gaskets the best ones to use?
10. Does anybody have any bottom end tips or mods worth doing for
somebody unfamiliar with the old Chevy sixes?
It would sure be nice to get this old six singin' it's song, but this
is a hobby vehicle and there is just no reason to hurry the job along. With
any luck a solid bottom end will be found and the motor can be reassembled in
a straightforward manner.
Paul O'Neil, Hudson29@aol.com
1951 Chevrolet 3600 Pickup Project, See it at:
The Poor Man's Advanced Design Tech Tips Page
http://home.earthlink.net/~conntest47/
Fullerton, California USA
AEROMARK - Need Rubber Stamps or Signs? See:
http://hometown.aol.com/hudson29/myhomepage/index.html
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