Passenger side rear is suddenly sitting lower

[Hilljack68]

I and a few friends took the Coronet out for a while yesterday. Upon returning, I noticed the passenger-side was about 1.5" lower than the driver-side (at the rear). It sat straight before yesterday.

A little background: She's a '68 Coronet 500/318/904 - a standard grocery-getter, but now with a mostly-stock 340. The springs were re-arched about seven years ago. I don't race her, but I will get into the four-barrel at least once every outing.

I haven't crawled underneath yet (we got home in a down-pour and I was in going-out-to-eat clothes). I guess my question is this... since the springs have already been re-arched, am I better off just laying out the cash for new ones? And if so, what do you boys like - ESPO, Mopar Performance, Hotchkis, Mancini, other?

 

[toolmanmike]

I and a few friends took the Coronet out for a while yesterday. Upon returning, I noticed the passenger-side was about 1.5" lower than the driver-side (at the rear). It sat straight before yesterday.

A little background: She's a '68 Coronet 500/318/904 - a standard grocery-getter, but now with a mostly-stock 340. The springs were re-arched about seven years ago. I don't race her, but I will get into the four-barrel at least once every outing.

I haven't crawled underneath yet (we got home in a down-pour and I was in going-out-to-eat clothes). I guess my question is this... since the springs have already been re-arched, am I better off just laying out the cash for new ones? And if so, what do you boys like - ESPO, Mopar Performance, Hotchkis, Mancini, other?

Espo.. Let us know what you find.

 

[Pikser]

Have yesterdays passenger drive tonight and see if that levels it out.

 

[Hilljack68]

Have yesterdays passenger drive tonight and see if that levels it out.

Yeah, my fat-*** friend Brian!

 

[WileERobby]

Inspect the suspension before you jump to conclusions. I've seen the spring perch/shackle crack, also the frame mount area rotted away.

 

[Hilljack68]

Ok, I spent a couple hours out there this afternoon. First off, the right rear tire was down about 12 pounds, so after re-inflation it helped a little, but there was still something else going on.

I measured the distance from the floor to the shackle bolt, and it was the same on each side... and I was officially perplexed. I remember reading somewhere that adjusting the torsion bar might serve to fix the tilted rear, but it didn't seem to make sense to me. But I figured, what the heck. I measured the suspension height on both LCAs, and they were quite a bit off. (They were perfect when I first rebuilt the front suspension, so I guess they settled in over the last year or so).

I got the LCAs as close as I could (per the shop manual), took her for a ride down the road and back, parked her on the concrete, and BOOM... perfect stance!

...then I washed her and had a beer.

 

[Hilljack68]

Inspect the suspension before you jump to conclusions. I've seen the spring perch/shackle crack, also the frame mount area rotted away.

That was actually the first things I checked. The shackle, front hanger, frame rail and the springs themselves looked perfect.

 

[WileERobby]

Ok, I spent a couple hours out there this afternoon. First off, the right rear tire was about 12 pounds, so after re-inflation it helped a little, but there was still something else going on.

I measured the distance from the floor to the shackle bolt, and it was the same on each side... and I was officially perplexed. I remember reading somewhere that adjusting the torsion bar might serve to fix the tilted rear, but it didn't seem to make sense to me. But I figured, what the heck. I measured the suspension height on both LCAs, and they were quite a bit off. (They were perfect when I first rebuilt the front suspension, so I guess they settled in over the last year or so).

I got the LCAs as close as I could (per the shop manual), took her for a ride down the road and back, parked her on the concrete, and BOOM... perfect stance!

...then I washed her and had a beer.

 

[Photon440]

Ok, I spent a couple hours out there this afternoon. First off, the right rear tire was about 12 pounds, so after re-inflation it helped a little, but there was still something else going on.

I measured the distance from the floor to the shackle bolt, and it was the same on each side... and I was officially perplexed. I remember reading somewhere that adjusting the torsion bar might serve to fix the tilted rear, but it didn't seem to make sense to me. But I figured, what the heck. I measured the suspension height on both LCAs, and they were quite a bit off. (They were perfect when I first rebuilt the front suspension, so I guess they settled in over the last year or so).

I got the LCAs as close as I could (per the shop manual), took her for a ride down the road and back, parked her on the concrete, and BOOM... perfect stance!

...then I washed her and had a beer.

So what was causing it to sit straight the day before you noticed that it was no longer level?

 

[AR67GTX]

Yes, often an uneven front suspension will create an even more unlevel rear stance. I have a C2 Corvette and it’s rather common with them although with close to 50/50 balance I’ve never fully understood why. With most pony and intermediate cars that are front heavy, a weak front spring or low torsion bar will make the lighter, opposite side, rear corner sit high.

 

[Hilljack68]

So what was causing it to sit straight the day before you noticed that it was no longer level?

That's the question I'm still asking myself. No idea. Maybe it was a slowly evolving issue. I normally back in to the garage, so I don't see the tail end very well when I approach the car. That day, because it was pouring rain, I pulled straight in. When I went to close the garage door, I turned around and saw it. Weird... I know it was fine a couple weeks ago.