Jacking points

[Shaun_E]

Can someone tell me the definitive jacking points for a 1997 De Dion car? If you have pictures showing the car jacked up then even better. I hope to see this on the "get to know your 7" day but I need a clue now as I am to have some tyres fitted and don't want the car damaged by whoever I get to fit them (current candidates Bracknell Tyres thanks to RichardO and F355GTS).

I have searched TechTalk but there is some disagreement. For myself I have a cheap trolley jack that doesn't go too low so blocks of wood to spread the loads aren't really an option.

Shaun

 

Yellow SL #32

[ROC]

My mechanic told me for a 2001 car (probably the same) that it is under the towing hook on the front (not where the cross members cross over) and in the center of the rear end, where the A frame joins the De Dion.

 

Check that they have the tyres before you go. When I went two weeks ago only three of the four tyre had turned up.

 

I too have a problem with my trolly jack not fitting under the car. My solution is to drive on to small blocks of wood before I start

 

Cheers Rupe

Click here p21 to see pics of my 7 on a Sri Lankan beach

[darren f]

Caterham;s manual says:

At the front- under the front ‘cruciform’ i.e. where the chassis tube diagonals cross (behind rad, in front of engine)- I use a ‘spreader’ piece of thick MDF to sit under the tubes.

 

At the rear- as Rupe says, under the De-Dion tube middle A-frame connection, although this is nor ideal because (1) there’s not much clearance and (2) it can be a bit unstable (use axle stands).

 

An alternative at the rear is either side where the chassis edge rail and cross rail meet, behind the rear wheel, the connection point is just at the front edge of where the fuel tank sits.

 

Hope this helps

 

darren f

 

The Building of R300SEV is Here

[ROC]

As Darren says, the manual does say the cruciform - which is where I had always jacked it. However, I was told by Gerard Holloway of Virtual 7 and formerly of Ratrace that it is not the best place as the frame is not designed to be lifted there.

 

This I admit seems odd with the manual telling you one thing (being written by the manufactures) and an engineer telling you another

 

I must admit, I'm with Gerard on this one. It seems to me that the frame is designed to take sudden shock loads in the corners, as the wheels hit various bumps in the road. Thus the frame must be very resistant to a vertical shock load at those points. The cruciform has nothing above it in compression and thus is putting a tensile load on the frame. Intuitively this seems wrong.

 

 

[Chris W]

When my SV was built this year at the factory, they only used one axle stand at the front on the cruciform and two on the rear where the chassis edge rail and cross rail meet. You can roughly see this on the pictures on my website (click below) - see "engine 1" and "engine 7" photos which were taken at the factory.

 

I asked Tim Ward, the production manager, about jacking points while I was at the factory and he said anywhere is OK providing it's where at least two rails come together. (ie: not on any isolated rail - cos it'll bend!)

 

Chris

 

1.8K SV 140hp see it here

 

Edited by - Chris W on 9 Apr 2003 21:02:23

[Graham King]

Shaun, they do cover this on the "get to know your 7" day, I did the last one.

 

Front: As Darren says under the cruciform (where the 2 diagonal bars meet the bar across the car), axle stands as far to the outer edge of the cross bar as possible.

 

Rear: As Rupe says in the centre where the A frame meets the De Dion, axle stands under the far outer edge of the A frame where it bolts onto the chassis tube. The De Dion does rise before the car starts lifting.

 

I covered my trolley jack and axle stand tops in bits of carpet so that they didn't damage the powder coating as well.

 

If you are putting the car up on 4 axle stands, do the rear first (chock the front wheels), and be carful when you take it back off the stands it is easy to pull it off the rear stands as you lower it down from the front. Do it slowly and if the rears start to move knock them back square with a hammer.

 

Sorry if teaching grandmother to suck eggs but heard of people damaging their cars by doing this too quickly.

 

Graham.

 

 

R7 GPK

[Shaun_E]

Thanks everyone - there seems to be a consensus on this now - previous threads have not reached agreement.

I am looking forward to the get to know your seven day as although I have a reasonable knowledge of basic car mechanics I don't know much at all about stuff particular to the seven. I also have no form of manual at all - wouldn't it be great if there were a Haynes manual! If anyone knows of any useful publication that would help with this then please let me know.

Thanks,

Shaun

 

Yellow SL #32

[SteveP]

The owner's manual (on a 2003 car) suggests that the jacking point for the front if you are just wanting to change tyres is under the lower wishbone, about half way acrosss. This has the effect of just compressing the spring and damper and gives enough clearance to get the wheel off.

 

 

SteveP

[Peter Carmichael]

Just to blow the consensus into the weeds, I would advise against jacking the de-dion tube in the middle.

 

In this mode, the dedion is put into significant shear and I think this is responsible for the cracking of de dion tubes. It doesn;t face this loading in use.

 

My preferred method at the back is to jack up the diff itself.