C1 rear ride height

[Donald H.]

I am finishing my rolling chassis. Can anyone tell me the correct ride height at the rear? Maybe from the outside of the rear crossmember to the ground?

I have reinstalled all the rear suspension, but not tightened the spring shackles, stabilizer bar, or the strut rods. I assume I need to have the car sitting at or near the ride height before I tighten these. I can bring the rear down to correct height with ratchet straps over the frame and axle.

I need to also tighten the front stabilizer bar. Should I have the front end at the correct ride height before I tighten it? The front height is given in the ST-12.

If so, any suggestion on how to bring the front down?

Thanks,

[Don H.]

Re: C1 rear ride height

The installation of the body will lower it significantly. Don H.

[Bruce B.]

Re: C1 rear ride height

I do not believe there is any relationship between ride height and how or when you tighten the suspension components. They all need to be tightened according to torque specs. The stabilizer bars float in rubber bushings therefore they are not set to any hight.
Ride height is simply governed by the front and rear springs.
The ST12 on page 0-1 shows body height as measured at the front and rear of the rocker panel.
These measurements are all done on a assembled car, so relating it to a rolling frame seems impossible to me.

[Gary C.]

Re: C1 rear ride height

Gentlemen, have been chasing this "ride height" ghost for a long time. Gary....

Please check the ST12 page 01 measurements against your cars:
- front of rocker panel (bottom) 6.7 inches from ground
- rear of rocker panel (bottom) 8.2 inches from ground

Report your year model and measurements

[Donald H.]

Re: C1 rear ride height

The installation of the body will lower it significantly. Don H.

I was hoping to tighten everything with the body off since I can get to everything easily.

[Tom B.]

Re: C1 rear ride height

When that chassis was going down the assembly line you know that they tightened everything before the body drop. It shouldn't be any different when doing it at home.

Tom

[Bruce B.]

Re: C1 rear ride height

Gary,
My 57 measures as follows:
Front, at splashpan screw 8 1/4 inches
Rear, at center of spring eye 9 1/4 inches.
My rear springs have 5 leafs and the correct P.N. in the groove.
Bruce B

[John H.]

Re: C1 rear ride height

Chevrolet Engineering specified ride height as a function of spring compression at design load. On C-1's, this was called out as the measurement from the centerline of the forward end of the inner lower control arm shaft to the ground (11", as noted in Figure 3 on page 3-2 in the ST-12, and in the "Specifications" section, page 14-1). For the rear, it was called out as the dimension from the top of the rear axle tube to the bottom surface of the frame rail directly above it (Dimension "B"), shown on the "Suspension Geometry" sheeet in the Assembly Manual, usually in Section 3 or Section 4. The front dimension assumes standard tire size (27" diameter), and the rear dimension is independent of tire size. All external body dimensioning to ground also assumes standard tire sizes.

In production, the front stabilizer bar cushion frame brackets and the rear spring front bushing bolts and rear shackle bushing bolts were torqued with the suspension compressed to design ride height so all of those bushings were unstressed in torsion at ride height.

[Donald H.]

Re: C1 rear ride height

Chevrolet Engineering specified ride height as a function of spring compression at design load. On C-1's, this was called out as the measurement from the centerline of the forward end of the inner lower control arm shaft to the ground (11", as noted in Figure 3 on page 3-2 in the ST-12, and in the "Specifications" section, page 14-1). For the rear, it was called out as the dimension from the top of the rear axle tube to the bottom surface of the frame rail directly above it (Dimension "B"), shown on the "Suspension Geometry" sheeet in the Assembly Manual, usually in Section 3 or Section 4. The front dimension assumes standard tire size (27" diameter), and the rear dimension is independent of tire size. All external body dimensioning to ground also assumes standard tire sizes.

In production, the front stabilizer bar cushion frame brackets and the rear spring front bushing bolts and rear shackle bushing bolts were torqued with the suspension compressed to design ride height so all of those bushings were unstressed in torsion at ride height.

Thanks John,

I had the front measurement from the ST-12. Just checked the AIM and found the measurement. It has two for the rear "design Load" which is with passenger weight included, the other is "Curb weight". Which did the assembly line use?

Also, any suggestion for compressing the front with the body off? I guess I can add enought weight to bring it down.

[John H.]

Re: C1 rear ride height

Thanks John,

I had the front measurement from the ST-12. Just checked the AIM and found the measurement. It has two for the rear "design Load" which is with passenger weight included, the other is "Curb weight". Which did the assembly line use?

Donald -

The compression fixture in the plant used the "Design Load" dimension.

For the front, just wait until the car is completed and on wheels to torque the stabilizer bar frame bracket bolts.