Folks,
A long time ago, I asked for help on dismantling a rear hub from the drive
shaft assembly on my 72 TR6. A lot of on- and off-list advice followed,
and although I could have "borrowed" a puller from a number of clubs (and
kind folks), the stories of how hard it was to remove the hubs using these
tools made me think twice (and then some more: just read Bob Lang's account
in the archives for a sense of how hard this can be: I couldn't run to the
number of heavy bodies needed, and the beer they would rightly consume
afterwards).
So, I ended up doing the dumbest of all options: deciding to design a hub
puller specifically for the rear hubs of the IRS cars. Folks kindly copied
details of several club-made versions of pullers available, and details of
the original Churchill tool.
I then worked with the students at our local skills center (in the UK, read
FE college) to get the OK for them to make a puller for me. Got the OK,
and the estimate for materials ($18, paid in advance whether it works or
not ... the only downside, but at that price, not much of a risk!).
The original Churchill tool employed an hydraulic system to multiply the
force applied by the large threaded center bolt. And we know this must
work, just look at the guy in factory manual: not a white knuckle in sight!
I knew I couldn't run to an hydraulic solution, but my long-time unused
engineering background did point me towards the thread forms that would
exert the greatest force per degree. This took me to fine thread forms
such as UNF, and even UNFF (yes, it does exist). The instructor I was
working with came up with the ultimate answer (many thanks to Robert
Espinoza of Saginaw Public Schools, Michigan, USA). He suggested using an
Acme-pattern fine thread: a thread form designed to transmit force rather
than provide land-to-land grip (the usual function of vee-form thread
forms). This required a custom threading operation on both the housing and
the 1" dia bolt. Incidentally, Acme is well known to all those who work
with manufacturing machinery where it is used extensively to move
cutting-related parts such as tables, cross slides, etc.
I can report that the tool made by the students worked superbly. After
removing the shaft from the car, I removed the outboard UJ leaving me with
a nice yoke into which I was able to put a very large bar. The bar was
then trapped under the tire of our boat-towing Oldsmobile Delta 88 (this
thing weights close to 4000lbs! and luckily is painted brown to stop our
local National Guard F-18's landing on the hood/bonnet). Nyloc backed off,
and puller fixed down. Very large wrench/spanner (2" A/F - this thing is
24" long) applied to the 1" Acme-fine threaded bolt, and tightened, and
then tightened, and then jumped on, and then tightened, and so on. After
10 minutes, and without me becoming frightened from bouncing off the wrench
(though it did flex a bit): BANG! a loose hub! The backplate is true, and
everything seems fine (including the rear tire of the Olds). This was a
single-handed job, just like the guy in the manual! No heat, and no use of
a hammer of any size!
If anyone would like a copy of the drawing of the hub-puller please let me
know off-list and I'll send you a browser-readable drawing (some lists are
a bit sensitive to attachments). Anyone within driving distance of
Midland, MI is more than welcome to borrow the beast. To those further
afield: I might be able to help, but I'm relutant to ship the beast to far
(it weights about 7lbs, and is a really awkward shape to pack), I would
prefer sending you a drawing and helping you make your own "beast." The
only proviso being that no one can make the "beast" for profit. If any
company wishes to make copies, then please wait to see if this isn't a
fluke, and if it isn't, then we'll talk about charities, but we're a long
way from that at this point.
Now, I just need to find out how to remove the large inner race and housing
from the wheel mounting backplate. Anyone got a dimensioned sketch of tool
S4221A with adapter 16? The outers came out as per manual. Any thoughts?
Thanks to all that contibuted to a really successful Triumph day!
Tony Gordon
72 TR6
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