Steering Column

[Steve Crook]

Hi Sean

Sorry about the very late reply to the steering column breakeage. I examined
the joint more closely and it appears that the clamp was not correctly
tightened and therefore all the rotating loads were being taken on the edges
of the outer tube (these edges are polished from the relative movement) this
would obviously put a lot of concentrated load into the outer tube edges
which could lead to a fracture starting at this point. When the clamp is
tight the load would be more evenly distrubuted around the tube and the risk
of fracture would be greatly reduced.
This is how I see the failure being caused so unless someone has other ideas
I would reccomend that we check that our nuts are tight, epecially if the
column moves in and out (that should get some comments).

Steve
----- Original Message -----
From: "Sean Murray" <***@***.***>

Sent: Monday, April 14, 2003 8:43 PM
Subject: Re: [LotusElan.net] Steering Column


Hi Steve,

Have you had a good look at the fracture, is it a clean break or is there
any evidence of a previous cracking which would indicate contributory
fatigue failure.

The less-than -solid mounting of the short steering tube in the +2 does not
help to avoid putting the shaft under stress at this point.
One reason I reinforced this area.

Sean Murray
----- Original Message -----
From: Steve Crook
To: ***@***.***
Sent: Monday, April 14, 2003 11:57 AM
Subject: [LotusElan.net] Steering Column


Has anyone had a similar failure to this?
An Elan+2S 130 was brought to me (on a trailer) with failed steering, on
examination it could be seen that the end of the top or steering wheel
section of the two piece shaft had sheared at the clamp which is fitted to
control the telescopic action required for crash protection ie the cut
away
piece where the clamp fits down in the footwell. The shaft had snapped
completly off at the clamp, luckily when the car was being pushed (yes it
is
a Lotus) my concern is has this occured to other cars and is this a
failure
point?. The car had been involve in a minor accident to the right front
and
while there was some body damage the wheel, a Lotus alloy, appears ok
although there are signs of slight damage to the tyre. Has anyone else had
a
similar failure or can this be put down to the accident damage?

Steve Crook

[ardee_selby]

--- Steve Crook <***@***.***> wrote:
<snip>

IIRC, the manual gives a torque figure for the bolts
(which hold the two halves together) but not for the
grub screw and locknut.

Q. Should the bolts be tightened with the central grub
screw pre-set in some way to touch the central shaft,
or are the bolts tightened and then grub screw
torqued/locknut tightened?

In other words...how is the correct interference
between grub screw and central shaft set?

Richard

__________________________________

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[conor1_ie]

Does anybody know the code for the stering column stalk for a +2.
It's the one with the indicators, lights and horn. Mine is a bit
dodgy when i want to switch the main beams on.

[gobw2]

Whew! big sigh of relief. George

On Fri, 16 May 2003 08:41:18 +0200 "Steve Crook" <***@***.***>
writes:
Hi Sean

Sorry about the very late reply to the steering column breakeage. I
examined
the joint more closely and it appears that the clamp was not correctly
tightened and therefore all the rotating loads were being taken on the
edges
of the outer tube (these edges are polished from the relative movement)
this
would obviously put a lot of concentrated load into the outer tube edges
which could lead to a fracture starting at this point. When the clamp is
tight the load would be more evenly distrubuted around the tube and the
risk
of fracture would be greatly reduced.
This is how I see the failure being caused so unless someone has other
ideas
I would reccomend that we check that our nuts are tight, epecially if the
column moves in and out (that should get some comments).

Steve
----- Original Message -----
From: "Sean Murray" <***@***.***>

Sent: Monday, April 14, 2003 8:43 PM
Subject: Re: [LotusElan.net] Steering Column


Hi Steve,

Have you had a good look at the fracture, is it a clean break or is
there
any evidence of a previous cracking which would indicate contributory
fatigue failure.

The less-than -solid mounting of the short steering tube in the +2 does
not
help to avoid putting the shaft under stress at this point.
One reason I reinforced this area.

Sean Murray
----- Original Message -----
From: Steve Crook
To: ***@***.***
Sent: Monday, April 14, 2003 11:57 AM
Subject: [LotusElan.net] Steering Column


Has anyone had a similar failure to this?
An Elan+2S 130 was brought to me (on a trailer) with failed steering,
on
examination it could be seen that the end of the top or steering wheel
section of the two piece shaft had sheared at the clamp which is fitted
to
control the telescopic action required for crash protection ie the cut
away
piece where the clamp fits down in the footwell. The shaft had snapped
completly off at the clamp, luckily when the car was being pushed (yes
it
is
a Lotus) my concern is has this occured to other cars and is this a
failure
point?. The car had been involve in a minor accident to the right front
and
while there was some body damage the wheel, a Lotus alloy, appears ok
although there are signs of slight damage to the tyre. Has anyone else
had
a
similar failure or can this be put down to the accident damage?

Steve Crook

[Rob_LaMoreaux]

I just bought a triumph GT-6 column to use the outer part since I have dents in mine. Anyway part of the inner dowel portion of the column came with it. It looks like it broken where the flat ended on the dowel, so there may be a stress riser there. Of course being a much heavier car it could just be that the light column couldn't take it in an impact.

So it might be good to magnaflux that part if you ever have it out of the car.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
Cell (734)-604-9280
***@***.***
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending adventure.

[Foxie]

Steve,

I find it hard to understand how a loose clamp can cause the steering column to fracture, do I remember correctly it was the inner rod that broke ? Maybe if I could actually see what it looks like it might make more sense to me.

You're certainly right about keeping the clamp nuts tight, although my experience has been that if they are not, it's very obvious from the feel of the steering.

Richard

I was not able to tighten the grub screw sufficent to remove all play, so what I now do is fully tighten the clamp bolts (26 - 32 ftlbs), wind in the grub screw until it is finger tight, open the clamp bolts, turn the grub screw in another quarter turn or so, and then retighten the clamp bolts and the lock nut. This gives a very solid result.

Sean Murray

----- Original Message -----
From: Richard Selby
To: ***@***.***
Sent: Friday, May 16, 2003 8:22 AM
Subject: Re: [LotusElan.net] Steering Column


--- Steve Crook <***@***.***> wrote:
<snip>

IIRC, the manual gives a torque figure for the bolts
(which hold the two halves together) but not for the
grub screw and locknut.

Q. Should the bolts be tightened with the central grub
screw pre-set in some way to touch the central shaft,
or are the bolts tightened and then grub screw
torqued/locknut tightened?

In other words...how is the correct interference
between grub screw and central shaft set?

Richard

[ardee_selby]

--- Sean Murray <***@***.***> wrote:

Thanks Sean...I was never much good at lateral
thinking. (or any other type come to think of it!!

Richard

__________________________________

The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

["Mark Spiers"]

When you say 'code' do you mean the wiring colours?

Rgds,

Mark.
----- Original Message -----
From: Batman
To: ***@***.***
Sent: Friday, May 16, 2003 4:53 PM
Subject: [LotusElan.net] Column Stalk


Does anybody know the code for the stering column stalk for a +2.
It's the one with the indicators, lights and horn. Mine is a bit
dodgy when i want to switch the main beams on.

[elanwrx]

Hi group.
I need some help.
I'm trying to remove the pinion gear from the steering rack. The
workshop manual instructions state "withdraw" the pinion gear after
removing the circlip and various other parts. I've removed the
circlip and the various other parts. I've also soaked the gear
assembly in penetrating oil for about a week. Still I
cannot "withdraw" it. I've tried a few persuasive techniques, but
have not been able to budge it. Any suggestions?
Thanks,
Jeff

[conor1_ie]

No I have the wiring colours. I Need to buy a new one and I think
theres a couple of different types.


--- In ***@***.***, "Mark Spiers" <elansprint3@h...>
wrote:

[EMA7K]

got a spare one in my box of goodies.....I'll have a look tonight
and see if I can spot the part number...or whatever....
cheers
G

[Steve Crook]

Sean

It was the outer that broke where it is cut away for the clamp. This is very
much a stress raiser especially if the clamp is not fully tightened. If you
can visualise it a tight clamp will clamp the inner against the outer tube
over a much larger area than if it was loose (by loose I dont mean that is
about to fall off). If the clamp is loose all the forces are on the edge of
the cut-out for the clamp and not distributed over a large area hence the
failure.

Steve
----- Original Message -----
From: "Sean Murray" <***@***.***>

Sent: Saturday, May 17, 2003 8:33 PM
Subject: Re: [LotusElan.net] Steering Column


Steve,

I find it hard to understand how a loose clamp can cause the steering column
to fracture, do I remember correctly it was the inner rod that broke ?
Maybe if I could actually see what it looks like it might make more sense to
me.

You're certainly right about keeping the clamp nuts tight, although my
experience has been that if they are not, it's very obvious from the feel
of the steering.

Richard

I was not able to tighten the grub screw sufficent to remove all play, so
what I now do is fully tighten the clamp bolts (26 - 32 ftlbs), wind in the
grub screw until it is finger tight, open the clamp bolts, turn the grub
screw in another quarter turn or so, and then retighten the clamp bolts and
the lock nut. This gives a very solid result.

Sean Murray

[Elan45]

Have you removed the little dowel that keeps the bushing from rotating. It drops into a hole half in the bushing and half in the rack housing. If it is still in there, it could be cocking and locking the bushing up.

Roger


I need some help.
I'm trying to remove the pinion gear from the steering rack. The
workshop manual instructions state "withdraw" the pinion gear after
removing the circlip and various other parts. I've removed the
circlip and the various other parts. I've also soaked the gear
assembly in penetrating oil for about a week. Still I
cannot "withdraw" it. I've tried a few persuasive techniques, but
have not been able to budge it. Any suggestions?
Thanks,
Jeff












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[Foxie]

Steve,

Yes, this makes sense, I've just been looking at the manual diagram of the steering column, Lotus have radiused the tube opening on the upper end, seems your type of failure is not completely unforeseen.

Sean
----- Original Message -----
From: Steve Crook
To: ***@***.***
Sent: Monday, May 19, 2003 10:56 AM
Subject: Re: [LotusElan.net] Steering Column


Sean

It was the outer that broke where it is cut away for the clamp. This is very
much a stress raiser especially if the clamp is not fully tightened. If you
can visualise it a tight clamp will clamp the inner against the outer tube
over a much larger area than if it was loose (by loose I dont mean that is
about to fall off). If the clamp is loose all the forces are on the edge of
the cut-out for the clamp and not distributed over a large area hence the
failure.

Steve

[gjz30075]

--- In ***@***.***, "elanwrx" <elanwrx@y...> wrote:

Jeff,
If you have the dowel removed, as Roger suggested, you might want to
try putting an old coupler on the splines, clamping it down, and
pulling on the coupler. It took a few wacks on the coupler to get
mine out.

Greg Z.
'72 Sprint.