Chassis Packing

[Matt_Harnden]

I’ve got the Opal on axle stands today ready to start some work to improve the alignment of the body.

Currently the vertical alignment of the coach lines between the hinge side of the door and the rear panel don’t line up too well. There is about a 3/4” drop and I want to try and improve this. I have fitted new hinge pins and the door shut lines are quite ok (although I have had to pack out the top hinge).

My plan is to add some hardwood packers between the body and chassis to try and slightly lift the body at the front half and hopefully then raise the door hinge point enough to improve the coachline.

Has anyone done similar work and do you have any tips? For example, should I add a packer under the cow horns or is it best to avoid this? Etc...

Thanks for your advice.

[Matt_Harnden]

A couple of photos to provide more explanation......

Matt

[squeak]

Matt, I would remove the spacing washers from the top hinge and this would raise the back edge of the door. The resultant larger gap in the back of door shut line could be improved by packing UP the body tub over the rear chassis extensions. Just my 2 cents cheers Russell

edit : on further thought IF this results in a "pinched" back of door shut line at the TOP, then add packing on the main chassis rails as well. You are moving the body UP relative to the cow horns, this will drag the windscreen forward, and the trailing edge of the door up. Any packing at the cow horns will result in misalignment of the starting handle to rad shell hole.
now 4 cents worth, cheers

[Martin Prior]

I’ve got the Opal on axle stands today ready to start some work to improve the alignment of the body.

Currently the vertical alignment of the coach lines between the hinge side of the door and the rear panel don’t line up too well. There is about a 3/4” drop and I want to try and improve this. I have fitted new hinge pins and the door shut lines are quite ok (although I have had to pack out the top hinge).

My plan is to add some hardwood packers between the body and chassis to try and slightly lift the body at the front half and hopefully then raise the door hinge point enough to improve the coachline.

Has anyone done similar work and do you have any tips? For example, should I add a packer under the cow horns or is it best to avoid this? Etc...

Thanks for your advice.

I cured a similar problem on my RP by putting a stack of flat washers into the body mounting points between the front chassis member and the scuttle bottoms.

[Matt_Harnden]

Matt, I would remove the spacing washers from the top hinge and this would raise the back edge of the door.  The resultant larger gap in the back of door shut line could be improved by packing UP the  body tub over the rear chassis extensions.  Just my 2 cents  cheers  Russell

edit :  on further thought IF this results in a "pinched" back of door shut line at the TOP, then add packing on the main chassis rails as well. You are moving the body UP relative to the cow horns, this will drag the windscreen forward, and the trailing edge of the door up.  Any packing at the cow horns will result in misalignment of the starting handle to rad shell hole.
now 4 cents worth,  cheers

Thanks Russell, currently there is already misalignment between the rad shell and starting handle and the body needs to be lifted to compensate for this. I’m going to use a combination of your ideas and those from Martin Prior (below). I’ll update you on my progress or lack of it. Matt

[JonE]

I'm having similar problems with the Nippy, including not enough space between the dash rim and the steering wheel which makes me think about splaying the body a little to improve things. I'd been considering that some of the design characteristics - a completely horizontal bonnet hinge line - mean that differential packing front and back is going to be needed... but it keeps coming back to the need to centring the rad shell on the starter nose cone.

I'd wondered whether different engine mount rubbers exist or different charactersitics on the feet on crankcases (for instance, once a sports crankcase is lost and a Ruby one adopted) start off some of the problems for body fit?

[Matt_Harnden]

I’ve got the Opal on axle stands today ready to start some work to improve the alignment of the body.

Currently the vertical alignment of the coach lines between the hinge side of the door and the rear panel don’t line up too well. There is about a 3/4” drop and I want to try and improve this. I have fitted new hinge pins and the door shut lines are quite ok (although I have had to pack out the top hinge).

My plan is to add some hardwood packers between the body and chassis to try and slightly lift the body at the front half and hopefully then raise the door hinge point enough to improve the coachline.

Has anyone done similar work and do you have any tips? For example, should I add a packer under the cow horns or is it best to avoid this? Etc...

Thanks for your advice.

I cured a similar problem on my RP by putting a stack of flat washers into the body mounting points  between the front chassis member and the scuttle bottoms.

Thanks Martin. Just to clarify, are you talking about the points highlighted below? Also, I’m unsure what you mean by “scuttle bottoms”? Cheers.

[Matt_Harnden]

I’ve got the Opal on axle stands today ready to start some work to improve the alignment of the body.

Currently the vertical alignment of the coach lines between the hinge side of the door and the rear panel don’t line up too well. There is about a 3/4” drop and I want to try and improve this. I have fitted new hinge pins and the door shut lines are quite ok (although I have had to pack out the top hinge).

My plan is to add some hardwood packers between the body and chassis to try and slightly lift the body at the front half and hopefully then raise the door hinge point enough to improve the coachline.

Has anyone done similar work and do you have any tips? For example, should I add a packer under the cow horns or is it best to avoid this? Etc...

Thanks for your advice.

Update (6/1/2018)

Just got back from the shed..... I have managed to fix one issue but created another. I guess that the flexible nature of the Opal body will give me some challenges!

Anyway, I removed the 4 attachements between the cow horns and the chassis and also the 4 attachments below the scuttle (as suggested by Martin Prior). I put the chassis directly on the axle stands the ensure there was no lift from the suspension. I have not loosened any other chassis to body bolts apart from the mounting collar around the steering column.

By carefully blocking and jacking the body off the chassis below the scuttle, I now have a 5mm gap under the cow horns and a similar amount under the scuttle connections. The gap around the radiator cowl has much improved and the top of the doors are level with the rear body. So we have some success!  However - the top of the shut line between the passenger door and the rear wing panel has opened up significantly, probably as much as 10mm.

Question: is it now best to pack and attach the cowhorn mountings and the four mountings below the scuttle so that I have a fixed point, or should I now loosen the rear chassis mounts and lift the body at the rear to try and I’m improve the shutline?

Thank you for any feedback!

[squeak]

Matt if you're happy with the fit so far, go ahead with the packing and bolt up the front half. If you're still happy then experiment with raising the rear half.
Bear in mind you will have then raised the body relative to the chassis along its entire length.
I'm not a fan of packing up the cow horns, some adjustment in starter hole fit can usually be achieved by slacking all the front panel bolts and pushing down on the rad cowl and/or raising the squashed rubber engine mounts.
Reduced packing at the front should reduce the requirement for packing all along the chassis particularly at the rear.
Thanks for the followup posting its always good to here results and good luck, cheers Russell

[Phil Kingdom]

I have never done Austin 7 body but have done a couple of Triumph Heralds, and I found it best to have all the fixing points loose to start with, when a satisfactory position is achieved with the spacers go around and nip up all the bolts a little bit at a time, recheck the alignment then tighten a bit more and repeat till every thing is tight, this way any thing that is out of line can be corrected as you go.