Lotus Elan

small or large front upright?

PostPost by: rdssdi » Thu Aug 09, 2007 12:51 am

How can the various uprights and stub axles be identifdied?

How can the "larger" bearing (GT 6) upright be identified from the "smaller" bearing Spitfire front upright?

Bob
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PostPost by: garyeanderson » Thu Aug 09, 2007 1:12 am

Hi Bob
All knock on uprights used the larger GT6 uprights, stub shafts
Bolt on wheels used the early spitfire equivelents.
The stub axles are 5/8"and 1 inch in diameter on the spitfire/bolt-on hubs The stub axles are 3/4" and 1.060" on the GT6/knock-on

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PostPost by: rdssdi » Thu Aug 09, 2007 2:24 am

What if a P.O. replaced a KO original upright with an earlier spitfire (bolt on) upright?

Would the hub fit onto the stub axle?

Could a larger (GT 6) stub axle fit onto a small bearing upright?

Bob
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PostPost by: garyeanderson » Thu Aug 09, 2007 10:43 am

Hi Bob
Inner and out bearings are different as well as the Hubs (Elan and
Plus 2 knock-on hubs are also different),stub axles and uprights. It would be easier for a upright assembly to be swapped onto a bolt on wheel car than a knock-on wheel vehicle but that doesn't mean much to the average Lotus home/pro mechanic. If it can be done wrong, it may very well be done wrong...

Gary
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I took a photo of the front upright page in the Dave Bean catalog. Get the catalog and read it, for the money, it has more usefull info than any other publication on the Elan and Plus 2 than any other document that is in print.
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PostPost by: rdssdi » Thu Aug 09, 2007 3:06 pm

Thanks Gary.

I have a Bean calalog. I will use it as a reference. I am now into front end alignment and wissh to cover all bases. Thanks again.

Bob
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PostPost by: billwill » Fri Sep 27, 2019 9:53 am

Front Suspension 1967 S3 coupe

Can you visually tell the difference between an upright for a bolt-on axle from an upright for a knock-on axle if no axle is fitted?

I would hate to take mine apart, including removing the axles from the old uprights only to find that I had got the wrong new uprights.
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PostPost by: Craven » Fri Sep 27, 2019 10:51 am

A good indicator but maybe not 100%, this cast in pip indicates a late casting that has the larger taper bore.
p1020878.jpg and
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PostPost by: Frogelan » Fri Sep 27, 2019 11:25 am

It is possible to do the full GT6 conversion to bigger bolt on hubs / bearings / axles / uprights...I have done this (part by error, then by design).

I have just one suggestion: whilst this works for Girling AR calipers (alignment) i have not tried it with the original calipers...

Is it possible to spot...no, IMHO.
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PostPost by: vxah » Fri Sep 27, 2019 11:27 am

The tapered stub axle hole is also smaller in the "bolt on" upright, if the two types were together you would see a visual difference.
My PO had fitted the wrong upright then by hand, ground down the taper to make the larger stub fit!
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PostPost by: Craven » Fri Sep 27, 2019 12:22 pm

There are a number of aftermarket hangers available that allow a variety of caliper to fit this upright.
GT6 hanger = P16 Spitfire hanger = P14.
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PostPost by: billwill » Fri Sep 27, 2019 3:21 pm

Can I tell by measuring the outside and inside diameters of the axle tapered hole with a digital caliper. If so does anyone know what the figures should be?
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PostPost by: vxah » Fri Sep 27, 2019 6:59 pm

Outside stub hole measures about 27.5mm on the big upright and small upright is about 26mm.
Inner hole size is 21.5 for big upright and 20mm for smaller upright.
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PostPost by: billwill » Fri Sep 27, 2019 11:55 pm

Thank you.

I will measure the pair (that I bought off a fellow member here) tomorrow, before I go ahead with ordering a new set of Trunnion bits from Sue Miller.
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PostPost by: billwill » Fri Sep 27, 2019 11:57 pm

vxah wrote:Outside stub hole measures about 27.5mm on the big upright and small upright is about 26mm.
Inner hole size is 21.5 for big upright and 20mm for smaller upright.


Are these for bolt-on axle stubs or for knock-on axle stubs ?
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PostPost by: vxah » Sat Sep 28, 2019 8:39 am

Knock on uses the big stub which needs a bigger hole in the upright.
Bolt on uses a smaller stub so the upright has a smaller hole for it to fit into.
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