Lotus Elan

Diff Stiffening Bracket - Extra Strong Design

PostPost by: ceejay » Thu Aug 25, 2011 1:15 am

I cant lay claim to this design, it was fabricated by the previous
blokes who owned my S2 elan. At that stage of it's life it
was raced all over the country side here in OZ.

Considering that the normal Diff stiffening brackets are simply
a piece of heavy gauge angle with a couple of bolt holes
drilled for the upper mount bolts. I note that some owners say
they can be a pain in the ass to assemble while removing/ installing the
Diff in the chassis, this design is neat because it becomes part of the Diff
and makes the installation a breeze.

As you will note, much of the strength comes from the front plate
which is secured by the four upper studs on the Diff housing, as
well as the way the bracket wraps alloy housing ears, the bracket has
been on the car before it came into my ownership in 1981.

During the refurbishment, a small amount of welding was required
on a weld seam that had cracked on the left side of the bracket, not
bad for being service for probably more than thirty years.

The Diff shown here is a 3.9, I also have a 3.55, and a 4.1, the mounting
flanges on all of the Diffs (Sourced from various Escorts) have been
modified to fit straight onto the elan prop shaft. the gearbox
ratios are of the ultra close variety, first gear is pretty tall when
running the 3.55.

If you like fabricating with sheet metal, you might like to make this
a project sometime, the measurements etc can be taken directly
from the Diff, but like all small sheet metal projects, it is best to
create cardboard template patterns first, and create your project
from that.
Have fun
Ceejay.
Attachments
1-diff-0040.jpg and
Refurbished 3.9 Diff.The alloy housing is the very early type, the type that is prone to breaking near the "upper mounting ears".
2-diff-bracket-0039.jpg and
This design encapsulates the alloy housing and the Diff casing. Note how the bracket "wraps" around the carrier ears.
3-diff-bracket-0038.jpg and
The view from the front.
4-diff-bracket-0041.jpg and
The bracket installed on the Diff and bolted up, it makes a nice assembly and is easy to handle and install.
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PostPost by: 512BB » Thu Aug 25, 2011 8:13 am

Yes.........all very well CJ, but beyond the abilities of most Elan owners I suspect, including me. I shall stick with my Lotus made bit of right angle and the much stronger, later type diff housing. The angle is not so difficult to fit, just a bit of juggling and a good dollop of silicon around the bolt to stop any leaks from that area, on a rebuilt clean diff anyway! Simples.

Leslie
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PostPost by: ceejay » Thu Aug 25, 2011 8:57 am

I didn't say that you had to do this, I was merely sharing
a good idea, if anybody lacked the metalworking skills
to fabricate the product, you could always take the design
idea to someone who has... There's no rocket science involved.
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PostPost by: ardee_selby » Thu Aug 25, 2011 12:00 pm

ceejay wrote: <snip> I cant lay claim to this design, it was fabricated by the previous blokes who owned my S2 elan. At that stage of it's life it was raced all over the country side here in OZ...the bracket has been on the car before it came into my ownership in 1981.
Have fun Ceejay.


Hi Ceejay,

It would be good to know the context of this...i.e. was it a direct solution to probs found when racing...or was it AFTER having experience with the standard stiffening bracket...and what power/torque was the motor putting out...

Cheers - Richard
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PostPost by: ceejay » Thu Aug 25, 2011 12:36 pm

Richard.
As I said in the original posting, it was on the car when I bought it, the elan at
the time was powered/raced with a Brian Hart all steel motor with an output way
up there (I don't know the output figures as it was too long ago).

As to why the bracket was used, I guess it was standard practice among the guys
racing elans at that time (1970's-early 80's). the known problems of the early alloy
diff housings were more than likely the reason for the bracket being designed and
built as shown.

A rather clever modular design I would say, and not all that difficult to fabricate,
I'm glad it was left on the car.... pity I did not also grab the Hart engine as well the
quaife Diff.... oh well, ya can't win'em all I guess.
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PostPost by: bilcoh » Thu Aug 25, 2011 8:57 pm

Interesting design for a bracket. I was thinking of the more standard bracket, but in some ways, this one feels easier to create, though more complicated.

Going sideways with the discussion, I wasn't aware of the upgraded diff case. Does anyone know when the switch was made, and any photos available of the uprated case? I'm guessing I've got an older style, but would be curious to understand the differences.

BTW, I did several searches but couldn't find anything on it. Another BTW, how do you old-timers on this board keep locating the old threads that newbies like myself can't find through the search? Computers for brains, I suspect? :mrgreen:

Thanks in advance,

Dave
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PostPost by: pamitchell » Thu Aug 25, 2011 10:09 pm

CeeJay;

Thanks for sharing. This would make a great test piece for a machinist apprentice to earn his papers!
Phil
1968 S4/SE FHC 36-7936
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PostPost by: ardee_selby » Thu Aug 25, 2011 10:10 pm

bilcoh wrote:Going sideways with the discussion, I wasn't aware of the upgraded diff case. Does anyone know when the switch was made, and any photos available of the uprated case? I'm guessing I've got an older style, but would be curious to understand the differences.

BTW, I did several searches but couldn't find anything on it. Another BTW, how do you old-timers on this board keep locating the old threads that newbies like myself can't find through the search? Computers for brains, I suspect? :mrgreen:

Thanks in advance,

Dave


Dave,
Re: Cases. See elan-f14/elan-elan-diff-case-t23480.html

Re: Finding stuff - I guess it helps to know it's there, somewhere, before you start looking for it.

Cheers - Richard
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PostPost by: bilcoh » Thu Aug 25, 2011 10:45 pm

Richard wrote:

"Re: Finding stuff - I guess it helps to know it's there, somewhere, before you start looking for it."

Yes, or having just posted on this 3 days ago :) Also helps to know just what terms to search. I got really close with "diff alloy castings", and if I changed "castings" to "casing", I'd have found it.

Ah well, maybe I'll be that good when I'm a 5th gear poster as well.

Thanks again,

Dave
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