Of assembling a Harley Sportster transmission after the case
has been modified for a ball bearing on the sprocket side.
Some projects are doomed from the start, and a big part of
experience is learning how to spot them in advance. My own Ironhead Sportster project from Hell
is a good example of one of those. I
didn’t.
This poor motorcycle, which had only accumulated some 12,000
miles in its brief tortured existence before I rescued it, had fallen under the
control of an idiot, who thrashed and trashed and jumped and dumped it within
an inch of its life, only abandoning it to the corner of the garage when the
oil coming out the transmission was equal to however much you put in. Then it became trade bait and payment for
debts, and changed hands several times before I wound up with it for $1000,
which proved to be way too much. Still,
it was a numbers matching original 1979, which is rare because they were so
ugly nobody bought one. It even still
has the 18” rear mag wheel.
The drive chain on a Sportster is on the right side, and the
transmission pops out the left side after you pull the clutch and a bunch of
other stuff. Where the mainshaft goes
through the right side case there is a steel insert cast into the aluminum case
and bored at the factory to fit a pressed-in bearing race that houses a series
of loose roller bearings held in place by a retaining ring on the one side and
a thrust washer on the other. When one
over-tightens the rear chain the load is felt as accelerated wear in those
rollers that can lead to bearing failure that causes the mainshaft to wobble
under load and wipe out the oil seal behind the sprocket, which then allows all
the oil in the clutch and transmission to run out past the shaft. If one is of the type to notice the oil, but
think, “Well, it’s a Harley, after all, they just mark their spot, right?”, and
do nothing about it, well, then it’s not surprising one would also not notice
that the oil stopped leaking out on the garage floor after every ride, mostly
because one never cleaned up the previous oil anyway, but tracked it into the
house, after which the old lady chewed on one for some time. Then, when one noticed the rear chain was
kinda sloppy because the bearing was chewed up, and took a Crescent wrench to
the axle nut and tightened that chain right up, plus a little for smoothness,
it was a good thing one had drag pipes on the bike, which made it less likely
that one heard the bearing sieze up and start to spin inside the critical steel
sleeve, cause that woulda made some noise, all right. Especially when the dry-as-a-bone gearbox
started to howl as the gears lost their alignment because the mainshaft was
going south and started rubbing the corners off the gears. But even for one so idiotic as to fail to
notice or understand the significance of all this, there comes a point where
the bike just wouldn’t go no more, so there it sat. And when I first pulled the sprocket off and
looked at the charred remains of the mainshaft and the hogged out guts of the
right side engine case, I knew I was hosed.
Screwed, blued and tattooed, as they say. So I parked it for a few years to see if it
would fix itself, say about ten.
Then I got introduced to Keith Johnson, a genius machinist,
welder, technologist and beer drinking hippy biker then creating strange things
from a garage along Lake Tapps. He had
run across this same problem in the past and created a spud to which you could
bolt the engine case half down flat on the table of a milling machine and pick
up the exact center of where the mainshaft bearing bore used to be, and
re-machine the case to fit a ball bearing.
He had turned up an old Harley Davidson blueprint from 1958 that showed
the dimensions of a counter bored pocket exactly five hundred thousandths of an
inch deep and 2.0476” diameter, apparently a modification requested by the
Racing Department, who were flogging the early Sportsters at dirt tracks all
across the country and needed more load capacity there. Keith proceeded to do just that through both
the steel insert and the aluminum case itself, working upside down from the
back side of the housing, and it came out right, an achievement that I take my
hat off to, speaking as a machinist myself fully aware of how tricky that job
was.
So that fixed the engine cases, and the frame had been
straightened and repaired by Darwin in White Center, so it was time to put it
back together. About 5 years later, one
day, innocently, Ron said, “You know, those projects are great to have, but
every now and then you gotta actually do one, right?” That’s when I knew it was time to get back on
the Sportster from Hell, and stay on it this time. I’ll let you know how it comes out.
Oh, yeah, one more thing.
When you replace the loose rollers on the sprocket side of the mainshaft
with a 6205R ball bearing, it turns out to be 15mm wide, or .590”, which does
not leave room for the stock thrust washer with the tang on the bottom that
matched the notch in the race that you’re not using any more, so you have to
find a thrust washer that matches the ID and OD but is about .040” thick, which
I found at Grainger under part number 4XFR4, to bring the end play down to about
.005”. The OD and ID are 1.540” and 1”,
respectively.
Then you discover that the mainshaft is .983” diameter and
the bearing you got is 1”, so then you cut a piece of feeler gage about .007”
thick on the bias so it fills the gap and slip it in between the shaft and the
inner race with some Loctite 609 to keep it there, knowing it will be further
retained by the sprocket on the outside and mainshaft low gear on the inside.
Here’s a copy of the factory drawing from 1958 that shows
the counter bore:
With that in hand, and a good machinist sitting in front of
a decent milling machine, you can get that wasted engine back in useable shape
again. Good luck. :-{)}
Revival
As I have been reminded of late, the project of bringing
back to life an old motorcycle that has been in storage, if not disassembled,
for lo these many years is not smooth and straightforward. There will be fits, and stops and starts,
parts lost and found, mistakes made, oh, yeah, lots of those…
I picked this bike up sorta as a favor for a friend, some
twenty-one years or so ago, and it was pretty thrashed, as detailed in the
previous installment of this story, titled “Trials and Tribulations”. The one thing it had going for it was the
fact that it was a numbers-matching original XLH-1000, but that was pretty much
the only thing. I’ve learned, for
example, that in 1979 the Sportster engines came with three different exhaust
valve diameters, 1 5/8”, 1 11/16”, and 1 ¾”, and that mine were the smallest,
meaning it was the cheapest of base model Harleys from the days when they still
produced the XLCR and the XR-1000. So
that put the kibosh on any thoughts of somehow breaking even financially on a
restoration project featuring this particular bike, especially given the bent
frame, hogged out transmission case and general state of destruction visited
upon it by a succession of idiotic owners, or one really bad one.
I decided early on that, because of the rough treatment it
had received, this bike was the Harley equivalent of the abandoned puppy, and
that the only proper response was to take it in and nurse it back to health, no
matter how long it took. I suspect the
main reason it survived all these years was because we only moved once in all
that time, which allowed the Sporty the luxury of rest, and of being forgotten.
After the initial rush of enthusiasm when the project
arrived, which resulted in some fortuitous parts finds like the new rear
caliper and brake rotors and the Koni shocks off the discount table at the
dealer and the frame being repaired and straightened by Darwin in White Center
and powder coated by Art Brass, the discovery of the ruinous transmission
damage put a ten year damper on the project, during which time it lived in
boxes under the bench. I gotta say that,
in all that time, the only good part I lost was the front upper motor mount,
and that’s a bummer, because all the cheap chromed aftermarket parts are junk
that must be reworked to even start to fit.
I’m still looking for that.
The assembly of the engine was delayed for a few years while
I tried to get the flywheel and crank shaft runout within factory specs. The early version of the crank had retainers
and screws around the crank pin nuts, the way they’d done it since the early
days, but, starting in late 1979, they dropped the retainers and substituted a
drop of Loctite 690 on the taper and tighten the hell out of those nuts, which
I never trusted, but there it is. I have
an old Shovelhead service manual that says to use a drop of battery acid in
place of the Loctite, which is newfangled.
I finally took it up to Steve at Burgin’s, who showed me you just gotta
hit it real hard in just the right place, after which it went together
fine. It hasn’t blown up yet, but I
haven’t taken it to the drags yet, either.
After that it was a fairly straightforward process of
assembly, test, say damn, disassemble, fix, reassemble, test, say damn some
more, and so on. The gas tank was so
full of crud after all the years of dry storage (yes, I know about oil storage,
now) that it plugged the petcock strainer so high that reserve fuel supply did
not work, causing it to run out of gas on its maiden voyage. The bike should have come with electronic
ignition, which started with the ’78 models, but had been converted to points
by one of the idiots, so I went with that.
Right off the bat the little tab that rides on the point cam broke in
such a way that it looked fine with the engine off, but lifted like a finger
when you attempted to start it, and collapsed the point gap. After we got that figured out I decided to
replace it with a nice Dyna-tech electronic ignition that I found in my pile,
only to discover that it was junk, but only after going to the trouble to
install it. Tell me why, please, why,
oh, why do people take junk parts off their motorcycles and keep them? Do they think time heals all wounds? Have they forgotten the simple fact that
electricity, at its root, is smoke, and when the smoke comes out the
electricity goes away? But I digress…
forgive me. The mind wanders when you
consider how you installed three different carburetors to fix an electrical
problem.
I learned many lessons during the course of this project,
some that bear repeating. I learned not
to buy new tires at the start of the project, wait till closer to the end, so
as to avoid brand new ten year old tires.
Same goes for batteries… I
learned that the shallow dish in the rear sprocket goes to the inside, and if
you guess wrong the first time it will rub on the chain guard and the sprocket
cover, which is bad. I learned that
camshaft end play is over rated, and can lead to head-bangers balls, which
explains Metallica.
I finally got it home from that ill-fated maiden voyage and
discovered that the shifter peg had vibrated half way out of the shift lever,
the clutch perch pin had been missing the retaining ring on the bottom and was
standing at attention. The right side
front caliper had somehow coughed up one of the nuts that hold the caliper to
the fork slider, squirting the shoulder bolt out the side and taking a chunk of
the hexagonal pocket on the inner edge of the casting with it. I noticed that while trying to figure out why
the front brakes quit working, and was that brake fluid all over the rotor on
that side? More damns… the left front
caliper was quietly disassembling itself as the big bolt that holds the halves
together backed out. Geez, who was the
idiot who put the brakes on that front end?
Oh, yeah, that guy… I’ll have to talk to him.
But slowly, almost in spite of itself, the list of things to
do got smaller and smaller. The
collector vehicle plate arrived in the mail, finally, and the left turn signals
actually fixed themselves, which was good, because there was no reason why they
shouldn’t, and I couldn’t figure out why they wouldn’t.
And so, after twenty-one years of breakdown and storage and
neglect and renewal, one of Harley Davidson’s equivalent to a teenager in love in
the ‘50s is now back on the road. I owe
many thanks to my guru team of Ron Fox and John Van Golen for helping me
through the starts and the stumbles. The
plan is to introduce it to the community at the Isle of Vashon TT in 2015, if
the Harley Gods be willing. We’ll see
you there. :-{)}}
