Excess Rear Wheel Camber ????

[Rich]

Also weird, your 245/60 tires at 33 psi should create added ground clearance. Makes me wonder if you have the wrong Coils on the shocks.

Yes, the tire size affects it a little bit.
The 245/60 vs 235-60 adds 0.25in to the tire radius so the equivalent ride height to achieve correct alignment geometry with the 245's mounted is 5.75in.
https://tiresize.com/comparison/

33psi vs (spec) 30psi tire pressure seems close enough but it's easy to deflate to 30psi just in case.

[nkemp]

... Refer to section R:02:XX in the Workshop Manual. ...

the problem is there is a car wrapped around the frame Making the measurements I need is going to be a challenge.

[David T]

the problem is there is a car wrapped around the frame Making the measurements I need is going to be a challenge.

Yes, BUT you don't have to make exact measurements and you can compare one side to the other. You can also look for any anomalies like welding, bulging, patches, rot, etc. If you find any discrepancies you can make more detailed measurements. In fact, you don't even have to measure. Just take a piece of string and compare things side-to-side. Another way to measure is to use a plumb bob and drop the points to the floor and then measure them on the floor. My point is it can be done and probably should be done.

[DMCMW Dave]

the problem is there is a car wrapped around the frame Making the measurements I need is going to be a challenge.

Is there any chance your car is missing the metal brace that goes behind the engine? That's attached to the frame AND body and if missing would explain a lot. Hard to see how the frame could be way out of tolerance if that part is in place.

http://store.delorean.com/c-305-8-1-0-frame.aspx Part ID #6.

[nkemp]

[QUOTE=DMCMW Dave;250056]Is there any chance your car is missing the metal brace that goes behind the engine? /QUOTE]

The brace is in place. I just checked it and there is a bit of play in it (which is curious). The bolt is not tight to the frame. As I recall, the problem with that bolt is that it uses a square nut held in a metal box under the frame. The box is a bit to large and the nut will spin (due to the box bending out of shape) when trying to remove it. You have to wedge something in to hold it tight. That all said, If the tower was bending in, it seems it should apply pressure to the bolt causing it to be tight due to interference and pressure.

Anybody know the dimensions between those mounting holes/bolts? The frame reference data shows measurements for the shock top mounting points and the bolts that hold the brace are a little inboard from those. But they are accessible from the top and easier to measure.

Albeit possible, It is hard for me to imagine how the shock towers could be moving inward with the brace attached. If mine are, then it seems many more cars would be also. If mine are, then is seems there would be indicators (cracks in the powdercoat & epoxy). Even without the brace it seems unlikely to move.

As background, I've had this car for over 30 years. When I got it there was some frame rust so I did a frame off repair (the frame is now powdercoated over the bare metal where needed and over the epoxy where it was good. Zinc rich epoxy base and two color coats). The main damage was to the trailing arms and to the under part of the engine crossover bottom plate. The trailing arms were replaced. The engine crossover was reinforced with a SS panel under the original panel which is still in place. The car also rolled into an elm tree (driver's rear bumper corner was damaged) but did not suffer significant damage (the tree died). DMCH did the repairs.

So the frame "looks" great.

When I diagnose things, I tend towards simple problems first. So simpler would be:
- Can the bushings remain firm in place yet the holes get stretched to one side?
- Are the tires, with the given wear, pushing the wheels into strong camber? Does this explain why it looks so good when first lowered and changes to bad after I drive
- Are there differences in frames from the factory? Different control arm mounting locations?
....
- other simple problems???
....
- Do frames change their dimension over time?

[David T]

Now that you have given some history and the frame has had damage (that has been repaired) it tends to suggest all the more strongly that the frame may not be the way it should. Perhaps all of the damage was not repaired, or not repaired properly. Measure the distance between the front wheels and the back wheels. it must be equal on each side. Easy to measure accurately and if that is not equal you have to figure other measurements are going to be bad too. Might be time to get the car to a frame shop and see if they can measure it and straighten it.

[dn010]

The difference I could tell between early/late frames was that they riveted the plate on the underside of the engine cradle on early frames where the lower links are located (I can try to take a photo of this later today). On later frames, everything is welded. I know this because I went from a late frame in my car to an early frame from vin 712. I do not recall any other differences. In short, perhaps it is worth checking these rivets on your frame, make sure nothing has loosened or has fallen out.

The frames were built in jigs and they must have been the same jigs for the whole period of production. The only difference I have every seen in frames is manual vs automatic.

[nkemp]

The wheelbase measurements look great at 95 1/8" each side (hubcap to hubcap). And that 1/8" error could be measurement error. I then measured wheel rim to wheel rim and there is about 3/8" difference. The longer side was the side bumped (it didn't get pushed forward). BUT ... there is more error in the rim-rim measurement due to front wheel angle.

In the scope of 1981 production, I'd call that pretty close to spec and side to side.

The lower control arm mounting box is riveted and welded (sure looks welded on the inside)

I checked the bottom of the engine crossover with a straight edge because it was easy. There is a very slight upward bow. about an 1/8".

[nkemp]

I measured the top of rear suspension to the bottom of the rear crossmember (which I presume to be on the same datum line as the center of the frame:
- Spec is 19.05"
- Measured 19" each side (there is a little bit of error in this due to position and difficulty measuring but it is pretty darn close ... not enough to cause the camber I'm seeing)

If the shock tower is moving (inward at the top), it should show up in this measurement. Nothing I see leads me to follow the frame being out of alignment theory.

Since I'm measuring ... the lower control arms :
- inner bolts are pretty darn close to 23 5/8" right center to left center
- outer bolts are pretty darn close to 52 1/4" right center to left center
- best I can tell, there is no difference in the original lower control arm and its replacement (now on the car for over 25 years)

I believe the upper control arms are original.

The top of the shock towers feel good, no distortion.

Bushings (uppers) are my primary suspect now. Any other thoughts?

[DMC5180]

Post some photos of the wheel in arch.