elan factory cv joints

["velocmac350]

brian. stev`s cv joints are excellent the best on the market.
particulary as new donuts do not have asbesdos content under EEC law
in them now? tried to paste some info if it will work with yahoo?
clive
D.1. Doughnuts

link in the drive train between differential and wheel hubs.
Originally developed for general application industry, they provide a
relatively cheap, robust and trouble free coupling for the automotive
industry.
Not only did they perform the function of the standard metal
Universal joint, but they also acted as a noise and shock insulator
in the drive train. They are also regarded as a weak link ? in
the
situation of drive train getting locked up for example, where they
would break up before the rather more expensive metal parts such as
the diff or gear box.
In practise, on the Elans, they create rather a lot of "wind up" and
thus a jerky, rough acceleration path. Only experience or great care
meant a smooth drive take up. As many road testers heavily criticised
this point, Lotus in conjunction with Dunlop developed the
interleaved coupling, with the idea of fitting it to their heavier,
more prestigious +2 models.
The design followed the earlier hexagonal doughnut, except there was
an extra metal plate bonded in to the metalastic rubber, between each
metal plate taking the mounting nuts and bolts, thus giving a 12
plate sandwich construction. The result was to reduce the stretching
effect of the rubber and thus reduce "wind up".
For a while Lotus listed both types of doughnut in their parts list,
but eventually retained the interleaved variety.
Despite their success, they were all rather prone to failure with age
and use. The failure was caused by the splitting of the rubber away
from the metal plates. This often only meant small cracks, but if the
doughnut was on the left the crack would open up until the doughnut
broke completely. At speed this could mean a failing drive shaft,
creating havoc. (there is even one report of an early +2 having half
of its wiring loom ripped out as the result of the cables getting
wrapped around a loose shaft!). In fact, as this was a potentially
dangerous failure, Lotus modified the last +2 130/5 drive shafts by
fitting a fail safe device, consisting of a small 1/4" peg welded
into the centre of the drive spider ends and a small piece of larger
tubing welded into the diff and the wheel hub spider on assembly. The
peg rotated freely within the tube, thus creating a safety catch to
any failing shaft. The drawback of these models was that the whole
rear suspension wishbone had to be unbolted and swung away from the
car in order to undo and release the couplings or drive shaft.
Many people now consider fitting the solid drive shaft conversion to
eliminate the drive "wind up" or "surge" and hopefully the cost and
trouble replacing the four doughnuts. Although Lotus did fit solid
drive shafts to the 26R racing Elans, these cars are very different
to the normal road Elans and were designed nearly from scratch in
order to meet circuit rather than road conditions and demands. It is
unbreakable if the maintenance free sliding splines can be totally
forgotten about, as any UJ and spline with a lot of movement usually
required extra lubrication and inspection for wear, particularly
in "dirty locations" as in the +2. The other consideration is that of
the change of drive train locking up. This could happen, say, by
taking a hump-back bridge at speed, flying into the air the
suspension goes on full droop and the splines and UJs physically lock
up ? the result being a stationary if not damaged drive train
when
the car lands. The landing and sudden "take off" of drive train could
possibly finish anything else off?. with the present costs of
diffs
and gear boxes, this possible problem may be worth considering! Talk
to Mick Miller or Spyder about their conversions.
The doughnuts on the other hand provide a progressive flexibility
through all angles and cannot physically lock up solid.

D.1.1. Types & Prices
The choice is really a matter of price and convenience. The criteria
is the fitting of any doughnut of the correct size (Hillman Imp range
is the same size as the Elan).
Thereafter weather you are considering standard or interleaved, you
pay your money and take your choice! Generally, the less money you
pay the lower quality the coupling. The following general list gives
some idea of the types available:
1. Lotus Interleaved Coupling, Part no BB026 0 0034 ? has the
stiffening plates and a special rubber mix. Recognised by a silver
paint test, (Indicating it has passed a Lotus specified stretch
test). Suitable for all Elans. Available from Lotus Dealers.
Introduced 1969.
2. Other interleaved couplings ? identical size and detail to
above
except for two paint marks. (Although some do have silver marks).
Thus quality cannot be assured. Available from Christopher Neil, Paul
Matty and even some Lotus dealers! Generally it can be assumed they
are suitable for all Elans although it is generally advised to check
condition regularly.
3. Talbot Imp Competition (Hillman Chrysler) ? similar to the
above
although rubber mix details cannot be confirmed. Fitted to
competition Imps. It is often suggested they are the same as above.
4. Lotus Standard Coupling. Part no A026 0 0034 ? without the
interleaved plates these were fitted to all Elans as standard up to
about 1970. Now withdrawn.
5. Other Couplings - these are often advertisements for cheaper
versions to the Imp couplings but in practise these often have a
harder or low quality rubber mix and do not give the flexibility of
other types, and in some cases the metal mounting sleeve does not
extend completely through the rubber coupling. Although they are very
cheap they would not be recommended. "You pay for what you get"
Obviously the Lotus genuine part is really the true recommendation,
however, if an owner is prepared to regularly check the couplings for
cracking and general condition then the alternatives may be
considered. It has been noticed, years ago, that some Lotus Dealers
have been dealing in non-genuine couplings at Lotus prices so check
carefully for the paint marks. The last point connected with
doughnuts is the bolts. They are not the same as the Hillman Imp
range but are Lotus Part no 036 D 0172 with Nyloc UNF 7/16th full
stoner nuts on the other end. The early Elans also used to have a
special washer fitted, but this has now been deleted and there is a
note in the Workshop Manual about it.

Doughnut bolts part No. OLD J056 replaced by 036 D 0172
Doughnut bolts (2) 7/8th X 2 7/8"
Stoner nut 7/16" Nyloc UNF full
Special washer 26 D 017 now obsolete
Workshop Manual section R1
Always coat bolts in Copperslip

D.1.2. The Do-Nut Debate
A report in Club Lotus magazine, in January 2002, starts the debate
all over again Mick Miller in conjunction with GNK. Motor sport. Have
developed a replacement drive shaft system, for Elan & Plus Two`s,
that feature constant velocity joints to eliminate the old fashioned
Rotaflex coupling. There have been some unhappy reports suggesting
that donuts "ain`t what they used to be" an information sheet from
Mick Miller tell us that some "environmentally unfriendly
constituents have been left out of the rubber resulting in a poor
quality" Some years ago a universally jointed replacement was on
offer, that came with length of rope to ensure that the system did
not lock up on if the car jumped over a humped back bridge, so
inducing full droop. The 26R Racing Elan had twin sliding splines
equipped drive shafts but of course these cars ran with extra
negative rear camber on smooth tarmac surfaces with a 160bhp plus to
transmit. Spyders have offered an other solution for several years,
this consist of one CV joint and one donut.
On the other side of the world, in Melbourne Australia Steve Taylor
at the Elan Factory, have developed there own Twin CV joint solid
drive shafts for both Elans & plus two`s The debate will go on and on?