Body to chassis bolt alignment

[cannonsami]

Hello all,
I'm finally fitting my S2 body to the frame, however, it's not the original frame for the car. I'm having trouble getting the bolt holes to line up with the bobbins in the body. I've been able to line up one of the ones in the backbone ahead of the shifter, but not the other, and I've also been able to line up both on the "T" piece of the chassis. It seems like the other one on the backbone should just fall into place but its at least 1/8" off. Is there a trick to it or is the second one on the backbone not lining up due to inconsistencies at the factory? thanks

[BDA]

My experience was a little different from yours but I wonder if it might be instructive.

First the differences: I have a TCS and I used a new Spyder frame (not the tube frame but I don't think that's important).

The holes for the ends of the 'T' were not drilled and neither were the holes at the end of the 'Y' of the frame. Of course, I don't have the angles welded on either side of the backbone to bolt the body to the frame from underneath the seats so I didn't have to worry about those. The holes in the frame to secure the body in front of the shifter were there and matched the body mounting holes, the best I recall.

So I'm guessing that Spyder didn't put holes in the frame where they thought the placement of the bobbins in the body may not match - thus the 'T' and the rear legs of the frame were not drilled. I would also guess that the other mounting holes were expected to be "properly" placed or their placement was at least more predictable.

Before I mounted the body on my frame, I expected to be able to move it a little to make sure it was in proper alignment but there was no way I could move the body in relation to the frame. With the closed cell foam I put between the frame and the body, it was a tight squeeze so I abandoned any idea to make fine adjustments to the position of the body and I just drilled the holes into the frame where the bobbins were.

I don't believe I've heard of anybody using a frame sourced from another car (I'm sure it's happened but I've just never heard of it). Surprisingly, it sounds like you are able to make fine adjustments in the position of the body to the frame. I would line up all the holes you can and just redrill the others. If you're really concerned about the 1/8" difference, you can try to use a thick washer inside the backbone.

[TurboFource]

I was able to use a piece of round bar smaller than the hole diameter and get things to line up the small amount a couple of the holes were off.

[EuropaTC]

Personally I wouldn't worry about getting perfect alignment and whilst you would expect a mainstream manufacture to have identical bodies & chassis which are interchangeable, this is 1960s Lotus we're talking about, a quaint cottage industry from rural Norfolk.

BDA mentions getting a blank, undrilled chassis, mounting the body and then drilling the holes. That's what I did when I replaced the Elan chassis and although I used a Spyder chassis, the method was exactly the same in the period if you bought a genuine Lotus chassis - they also came undrilled. The idea was you mounted the body on the bare chassis, marked through the bobbins, lifted the body off then drilled/tapped the holes. I don't know but it wouldn't surprise me if Lotus did the same on the production lines, after all they put it in their workshop manuals.

Whilst every effort is made to keep the centre dimensionsof off the bobbins within reasonable limits, it is recommended that the chassis be 'offered up' to the body before any assembly is undertaken. A visual check should be made for any holes that may not align with their respective mounting points in the body shell . These may be elongated iust sufficiently to receive the mounting bolts. Drill ond top chassis(with body tempororily in position) to accept the mounting setscrews of:
a. Front suspension uprights.
b. Rearbody cross-brace.
c. Intersection of top flanges of front side member.

So matching a body and chassis from different cars, well I wouldn't expect them to line up. If they did I'd be amazed and delighted, but my world doesn't usually run like that.

If I were you I'd use the sacrifical screwdriver to lever the body over the holes as best you can, then I'd drill out any misaligned bobbins to match the chassis. If it's so far out that you're going to weaken the bobbin too much, say cutting through the side, then I'd mark up through the bobbin, lift the body, weld up the non-aligned hole and drill a new one.

Have fun !
Brian

[Bryan Boyle]

Hello all,
I'm finally fitting my S2 body to the frame, however, it's not the original frame for the car. I'm having trouble getting the bolt holes to line up with the bobbins in the body. I've been able to line up one of the ones in the backbone ahead of the shifter, but not the other, and I've also been able to line up both on the "T" piece of the chassis. It seems like the other one on the backbone should just fall into place but its at least 1/8" off. Is there a trick to it or is the second one on the backbone not lining up due to inconsistencies at the factory? thanks

Using the center 2 bolts as the reference...first, don't tighten anything down until you have all the holes set.  Second, locate using the two forward of the shifter, then see where the 6 bolts at that base of the firewall line up.  if you have a couple that are good there, bolt them up snug (not tight), and drill out the remaining ones at the firewall base.  Use flat washers under the nuts, again, snug them up, not honk down on them.

Then move to the T.  look down through the bobbins.  Close?  If not, drill out the frame.  Again, flat washer under the nut.  Then go to the rear of the Y.  How far out are you?  Do the same there, leveling the body by putting washers between the body and the frame.. 

Then go back, starting with the bolts forward of the shifter, and tighten down.  Base of the firewall.  Front T.  Rear Y. 

After decades of use/abuse/storage/whatever...especially if you're not mating the body to the frame it came with, you will have to adjust.  These were hand-made, and each one is just a little different.

This is what worked for me on more than one body drop onto a frame.  YMMV.

[Fotog]

That's a lot of good, thoughtful advice!

Vince

[4129R]

I have had trouble lining up the holes for the seat belt mounting bolts on the centre tunnel.

All I did was drill larger holes in the oval bobbins. End of problem.