Lotus Elan

Sprint- Spyder chassis jacking & propping

PostPost by: stuartgb100 » Fri Dec 23, 2005 5:53 pm

Hi,

I'd like to lift the car some 6-8 inches completely off the ground for a two to three week period.

I need sufficient access for a complete exhaust system + manifold change, together with a strip down and rebuild of rear struts and driveshafts.

I've got trolley jack, two ramps, two axle stands + blocks of wood.

Sorry, but I don't know the Elan that well yet, and an awful lot of it looks pretty fragile (come to think of it, an awful lot looks pretty ...... period !) from the point of view of jacking/propping.

At the front, I'm pretty happy with a couple of axle stands, one at either end of the tubular chassis x-member.

Question is, what's best at the rear, bearing in mind the sort of access I'm going to need to remove/replace suspension and driveshafts, exhaust etc?

I'm a little concerned about the whole thing rocking when trying to work at the rear.

Can I do this safefully in one hit, or best to limit it such that only one axle is lifted at any one time?

Regards,

Stuart.
stuartgb100
Fourth Gear
Fourth Gear
 
Posts: 901
Joined: 10 Sep 2005
Location: Cambridge UK

PostPost by: type26owner » Fri Dec 23, 2005 6:23 pm

The rear lifting points on the baby is at the front corners of the rear wheels on the fiberglass body. I place a 2x4 along the intersection of the flat bottom panel and the fender skirt. A wide stance jackstand or a pile of wooden blocks will do to give it the height and make it stable enough so you cannot push like hell sideways and have it accidently tilt or slide it off onto yourself. All four corners lifted up with about 6 inches of ground clearance under the wheels at full droop is about the ideal height for working at ground level.

Working on the rear struts requires those moments of maximum exertion of force. Be careful. I normally completely remove the strut assemblies to do the bearing replacement on the workbench. On the workbench I have a 30-ton hyraulic press and can heat stuff up with heat lamps.

Remember to follow Dave Bean's advice for the struts. They are real proven safety hazard (the axle breaks off at high cornering forces) if not obeyed.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: stuartgb100 » Fri Dec 23, 2005 6:52 pm

Keith,

Thanks. The reference to the rear jacking points being on the underside of the cill, below the rear seatbelt mounting point, is what I thought would be advised.

However, having just replaced one structural lattice/rod assembly within the cill, I'm surprised how 'flimsy' it seems as a jacking/propping point.

I'm sure your're right, but just in case, can I send you the bill if all goes
't'ts up' ? ........... and would you pay? (vbg).

Regards.
stuartgb100
Fourth Gear
Fourth Gear
 
Posts: 901
Joined: 10 Sep 2005
Location: Cambridge UK

PostPost by: type26owner » Fri Dec 23, 2005 7:05 pm

It's the vertical panel that gives it high strength so stay under that intersection. Every engineer knows the inherent weakness of applying a force perpendicular to the plane of a thin flat panel. That's why the floor section of the body is like that. The raised 3D section under the seat and the ribbing give significant stiffness to the occupants loading.

My second biggest fear besides having a stupid deer run in front of me is having a piece of debris come up through the flimsy floor and clobber me. Plan on armoring the floor and fender someday, maybe before the start of the trackdays for next year.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: nebogipfel » Fri Dec 23, 2005 7:28 pm

I feel I should beg to differ with Keith on his advice for the rear end.

I would personally never lift an Elan via the shell, it is not strong enough. OK it will not collapse but you are risking lovely stress cracks! You are also placing great loads on the mounting points (have you seen how thin the shell is in places?)

I would lift the centre of the chassis (beneath the diff) using appropriately placed wood blocks. If you need to take some of the weight off a rear corner a small block on the extreme outboard end of the wishbone would be OK lifting with even a simple scissor jack.

I recently had the shell off my car and having seen it in closeup would never place these sort of stresses through it.

Opinions do differ on this subject, so this is my two pence worth :)
John

No longer active on here, I value my privacy.
User avatar
nebogipfel
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1588
Joined: 25 Sep 2003
Location: Norfolk UK

PostPost by: type26owner » Fri Dec 23, 2005 7:39 pm

Hey John,
Have you ever taken a close look at the model of car that came before Elan? The first Elite is a fiberglass free-standing, fully stressed structure which is quite an engineering wonder and achievement. The only major flaw was the suspension bobbins tended to shear off the bodywork from time to time. Chunky had big brass ones for sure. :oops:

BTW, I also never lift the car by the bodywork, only support there.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: elansprint71 » Fri Dec 23, 2005 7:56 pm

... no engineer in his right mind would lift the weight of the car using the bodywork.
Reverse up the ramps and get the exhaust off, lift the front end onto the axle stands (a decent piece of plywood on each will spread the load), then support the rear of the car by placing stands under the centre of the chassis- I use a cut-off from a builders plank so that I can place the stands about a foot apart, thereby ensuring the rear end is rock steady.
Even when the body was new it was barely up to taking the weight, it was reliant upon the steel reiforcing bars; you rightly suspect what has happened since then. The glassfibre of the Elite is considerably thicker than the Elan and a special type of scissor jack was supplied.

Cheers,
Pete.
elansprint71
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 4092
Joined: 16 Sep 2003
Location: Cheshire, UK.

PostPost by: nebogipfel » Fri Dec 23, 2005 8:27 pm

Yes the Elite was designed to be a fibreglass only (more or less!) structure and was much stronger than the Elan

Still not a good idea I would respectfully suggest :)

I'm not saying 'glass cannot be strong enough but Elan 'glass certainly is not

The Elan shell is VERY thin and VERY flexible and horribly prone to stress induced cracking which may not impair the strength too much but looks ghastly.

If you are talking about jacking verses supporting, ultimately the stress through the shell and loads on the bobbin/mountings are pretty much the same.

We all have to decide for ourselves but my Elan is lifted via the chassis and supported on the chassis.
John

No longer active on here, I value my privacy.
User avatar
nebogipfel
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1588
Joined: 25 Sep 2003
Location: Norfolk UK

PostPost by: stuartgb100 » Fri Dec 23, 2005 8:30 pm

Pete,

Just to be clear.

Reverse up the ramp and remove box etc .... ok.
So elan is now on rear ramps.
Lift front onto axle stands ..... ok.
So elan is now airborne.

You post said:
"then support the rear of the car by placing stands under the centre of the chassis- I use a cut-off from a builders plank so that I can place the stands about a foot apart, thereby ensuring the rear end is rock steady."

I do not understand this. I think I need some stability at the margins/ perimter here. because of the likely rotational forces required to remove hubs etc

Regards.
stuartgb100
Fourth Gear
Fourth Gear
 
Posts: 901
Joined: 10 Sep 2005
Location: Cambridge UK

PostPost by: type26owner » Fri Dec 23, 2005 9:06 pm

.. no engineer in his right mind would lift the weight of the car using the bodywork.

We're in agreement then. Chunky (Colin Chapman) was nuts! :lol:
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: 1964 S1 » Sat Dec 24, 2005 12:20 am

Stuart, I'm with Pete on this one, his method is nearly identical to mine and I've never had a problem in 22 + "Lotus" years. The ramps are great at either end, you may have to drive up on a thick short plank to get the ramp under the lower valence, and then, with great skill, drive up on but not over! Or, I've jacked mine up first (always using the chassis,) and then put the ramps or stands underneath, depending on the work to be done. At the rear I've never jacked, supported or lifted using the fiberglass corner due to concern about bobbin damage on a 42 year old "prototype" shell. And you'll be tugging [a bit] with the halfshafts. I have used on my +2 a plank, run underneath the width of the car, placed perpendicular to the driveshaft at the front edge of the rear wheel wells with jackstands near the outer ends. I shimmed it so the chassis took most of the weight but the stands were far apart safe and stable. Or, create some cozy wooden blocks for jackstands that fit just beneath the rear strut/bearing housing, and at front, outer chassis corners. Where to hold it up for strut removal, the debate rages, there are at least four other discussions in the archives on this subject. The old style garage pit would serve us all well. Good Luck! Eric
1964 S1
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1496
Joined: 15 Sep 2003
Location: Hamilton County, Ohio

PostPost by: sk178ta » Sat Dec 24, 2005 1:40 pm

East of the Pecos I have a reputation as well experienced in the removal of Lotus rears but modesty precludes boasting of my prowess or scorning engineering genius. So I compliment Pete on his excellent advice, but I would go further. Remove the exhaust on ramps then place a plank across the rear ahead of the diff. supported on crates leaving plenty of work room. The weight will be taken on the chassis and a little padding will prevent the body rocking/moving and protect the shell.
Jim
sk178ta
Second Gear
Second Gear
 
Posts: 132
Joined: 08 May 2004

PostPost by: mark030358 » Sat Dec 24, 2005 5:29 pm

Hi there,
To lift the rear my friend has made a tool which fits between the A frames as close to the wheel as possible. The tool or bar is then jacked in the centre using a trolley jack, hence all the weight of the .lift is taken on the suspension. When high enough, a 6"x2" plank of wood, the width of the rear of the car is is used to support the body on axle stands. Note that the exhaust has to be off. The plank is shimmed under the chassis to help weight distribution. Basically same idea as the last three posts.

merry xmas

Mark
User avatar
mark030358
Fourth Gear
Fourth Gear
 
Posts: 916
Joined: 29 May 2004
Location: Willaston, Wirral

PostPost by: berni29 » Sat Dec 24, 2005 5:59 pm

Hi

For jacking up the rear of my +2 (Spyder chassis) I fabricated a "U" shaped support where the upright parts of the "U" shape meet the chassis and the exhaust sits inside the "U". I place it more or less parallel with the first wishbone bush. Works fine. If I want one side up then I put a long piece of wood under the sill and jack on that. I have in the past actually used the standard jacking points as well!

On the Spyder chassis the front member is round (and on my car oily) and once the support slid out from under it. I was thinking "that looks a bit off centre" as it fell off. Luckily the steering rack support is very strong. I was not under the car but in the process of raising it. Never get underneath untill you have something solid and well placed under there.

Berni
Racing green +2s with green tints. See it at:

www.searchsmart.co.uk/lotus
User avatar
berni29
Third Gear
Third Gear
 
Posts: 387
Joined: 10 Mar 2004
Location: Beckenham Kent

PostPost by: 1964 S1 » Sun Dec 25, 2005 6:30 am

I love this site, I love Lotus, can anyone imagine a more complex discussion on how to jack up a car?
1964 S1
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1496
Joined: 15 Sep 2003
Location: Hamilton County, Ohio
Next

Total Online:

Users browsing this forum: No registered users and 11 guests