Trim height measurement questions

[Tom L.]

In the past I noticed that my car does not sit properly. Recently I did some suspension work in the rear of my car and it did not correct the problem. Before I begin a discusssion about what I see I wanted to take some measurements.

My AIM has the trim heights listed but some are unclear to me, so here's my questions:

1. Where is the Z dimension taken on the outer part of the lower a-frame? At the center of the ball joint? Lower part of the treaded end? Or at the spindle?

2. Are the E and J, and K and F the same dimension (there is only a nominal diffrence in the chart) and where is the measurement taken, from the frame or rocker panel to the ground?

3. It appears that the half shafts are supposed to be level, is that correct? there is no clear undicator other than the line drawn through it.

Thanks in advance!!

[Tom L.]

Re: Trim height measurement questions

Hmmm... no bites. I scanned and attached the page from the AIM, perhaps that'll help. Thanks

[Timothy B.]

Re: Trim height measurement questions

Lynn,

When I checked my 63 I used the lower stud on the lower ball joint to floor then from the center of the lower control arm bushing bolt to floor. Compare the difference from side to side then to book spec.

The rear measurment process is in the archives.

[Alan S.]

Re: Trim height measurement questions

Hi Lynn,
Is your car completely back together. The weight of a few items can affect the height... I'm thinking of the amount of gas in the tank, the battery, and the spare tire.
When I checked ride-height on my 71, I first checked the P and R dimensions. The height of the tire, (about 26.9" originally), affects these dimensions, but it's pretty easy to check, (and adjust for a different height tire if needed), and it gives you a general idea of what the situation is at each wheel.
Regards,
Alan

[Stephen L.]

Re: Trim height measurement questions

Lynn, the "Z" and "D" dimensions look for a differential measurement between the 2 points as shown on the drawing supplied in an earlier thread reply. This measurement negates tire height.
If these dimensions are within spec then the suspension and frame are within specs. Now if you measure the body points side to side and front to back this will tell you if the body is on the frame correctly or the frame has a problem. You'll need to take into account tire size by again looking at the chart and if ALL body point dimensions are off by the same amount then the tire height difference from original tires will be the answer.
Just follow the directions for the points. The 1/2 shaft in the drawing is for illustration purposes and doesn't necessarily indicate that the shafts are horizontal.

[Tom L.]

Re: Trim height measurement questions

Tim, So you used the bottom of the stud. While there is no clear indication I would think that the measurement would be taken at the center of the "ball" in the joint that the suspension point rotates on. I'll check and see.

Alan, all the things you mention are in the car. The only item of significance that is not are the mufflers, I simply couldn't get under the car to tighten the suspension bolts so I left them out for the time being.

Steve, I'm aware that the Z and D measurements negate tire size, I just want to take a bunch of measurements as correctly as I can before the car goes back up on stands.

Once I take measurements and determine if they agree with what I "see" I'll post more. I want to be able to respond to suggestions with real info before I get into that.

Thanks!!

[Timothy B.]

Re: Trim height measurement questions

Lynn,

Now you have jogged my memory, I may have used the lower boss (flat) on the spindle to the floor. Let me check my 63 AIM and see what it says because that's the way I did mine.

[Stephen L.]

Re: Trim height measurement questions

Lynn, I used the lower side of the "boss" of the spindle as suggested and the center line of the "A arm" shaft and my dimensions worked out correctly

[Tom L.]

Re: Trim height measurement questions

Thanks to all who replied. Just thought I'd report on my findings. I mentioned that I went through the rear suspension, here's what I did:

1. Replaced all bushings
2. Replaced trailing arms and had bearing assemblies rebuilt.
3. Replaced the spring with a used original (New liners, retainers, paint), one leaf on mine was cracked
4. Replaced brake and fuel lines....UGGGH!!
5. Replaced the seals in the rear
6. Gave everything a good cleaning and painted the frame and reinforcements

Once I got everything into the car; spare tire, fuel, battery, etc... and aligned the rear.

Befor the did all this the car sat weird, I was hoping it would be corrected. The rear was a little low (probably the spring and old bushings), it leaned to the right and the right front was lower than any corner. After all the work the rear came up (maybee too much but I'll see after I drive it a bit) but the right side was still low and the right front even lower.

I took a boatload of measurements and from what I can see the right front of the frame is indeed a little low (coil springs, bushings?). Everything else is at or very close to spec, taking the + or - into account.

The body itself is the culprit it seems. It must have been put on the car that way way back when OR when I had the body re-done it wasn't put together quite as straight as it was. There were a LOT of panels replaced.