Installed a new rear, now the ride is stiff

Posted By: plymouthfan

Installed a new rear, now the ride is stiff - 05/03/10 12:46 PM

Maybe I'm overlooking something stupid and very basic, but I'm perplexed.

I swapped out the 7 1/4 rear for an 8 3/4 in my Scamp. I reused the springs and shocks which weren't that old to start with. The springs are ESPO's 1" overs.

The ride before was fine. Suddenly it's VERY stiff. If you push down on the back of the car there's very little give. I can't figure out what's causing it... makes no sense, lol

Posted By: bobby66

Re: Installed a new rear, now the ride is stiff - 05/03/10 02:35 PM

Did the angle of the shock absorbers change? Is the new rear hitting something in it's range of travel? Did you tighten the fasteners with the weight of the car resting on the suspension?

Posted By: JeffC

Re: Installed a new rear, now the ride is stiff - 05/03/10 02:37 PM

Did you torque the springs with the car in the air or on the ground?

Posted By: buildanother

Re: Installed a new rear, now the ride is stiff - 05/03/10 02:57 PM

Did the rear shackles flip forward by chance?

Posted By: 440newport

Re: Installed a new rear, now the ride is stiff - 05/03/10 03:10 PM

Did you shorten the driveshaft? Are you sure the yoke is not bottomed out in the trans?

Posted By: MonGoo$e

Re: Installed a new rear, now the ride is stiff - 05/03/10 03:51 PM

Quote:

Did the rear shackles flip forward by chance?

I'm leaning on this qoute. When i did a Challenger, I had ESPO 2" over springs, first day or so, the shackles wanted to flip completely forward..after sitting car down, I was able to bounce back of car around and somewhat force them back to straight up and down, after about a week they went to more the correct position.

Posted By: MileHighDart

Re: Installed a new rear, now the ride is stiff - 05/03/10 04:45 PM

I have almost the same problem on my 68 Dart.

Swapped from 7-1/4 to 8-3/4 and at the same time I switched from the original 5-leaf springs (/6car) to new 6-leaf 1+ ESPO springs. Car is very stiff in the back, you can hardly bounce it my hand at all, and the ride is quite stiff now.

I went from 5 leaf to new 6 leaf. (I fugured the /6 cars used 5 leaf and V8 cars used 6 leaf, thats why I went with the 6 leaf) But I didn't think that was going to make the car ride like a buckboard !

Posted By: MileHighDart

Re: Installed a new rear, now the ride is stiff - 05/03/10 04:50 PM

Quote:

Quote:

Did the rear shackles flip forward by chance?

I'm leaning on this qoute. When i did a Challenger, I had ESPO 2" over springs, first day or so, the shackles wanted to flip completely forward..after sitting car down, I was able to bounce back of car around and somewhat force them back to straight up and down, after about a week they went to more the correct position.

What is the correct position exactly ?
I just went out to the shop and checked mine, and the shackles are pretty much straight up and down.

Posted By: MonGoo$e

Re: Installed a new rear, now the ride is stiff - 05/03/10 05:48 PM

straight up and down are acceptable, 100% correct are when the leaf spring portion of shackle is towards the rear of the car.

Posted By: MileHighDart

Re: Installed a new rear, now the ride is stiff - 05/03/10 06:00 PM

Quote:

straight up and down are acceptable, 100% correct are when the leaf spring portion of shackle is towards the rear of the car.

Do you think it would have Any effect on firmness or softness of the ride, if I was to put like a 1/4" shim under the rear frame mounted shackle mount, moving it forward, thus making the shackle angle towards the back of the car more ?
Just an idea, but I have no idea if it would help the ride any.

Posted By: MonGoo$e

Re: Installed a new rear, now the ride is stiff - 05/03/10 06:45 PM

I'm not sure, I doubt your specific ride height is hurt by that straight up and down, the leaf is still doing it's job.
I just know when one uses something like an extended spring shackle, it will flatten a spring out. But I know that's not what you're doing.

Posted By: scratchnfotraction

Re: Installed a new rear, now the ride is stiff - 05/03/10 07:12 PM

spring eye of shackle should be in the 4 to 5 O-clock position at ride hieght.

per the mopar chassis book

Posted By: plymouthfan

Re: Installed a new rear, now the ride is stiff - 05/04/10 10:50 AM

Quote:

Did the rear shackles flip forward by chance?

Bingo. I went out and looked at the car before I went to work yesterday and noticed they were flipped all the way forward, facing upwards actually. I guess I never noticed when I lowered the car.

As far as correct position, there's a diagram in the archives.

http://www.moparts.org/Tech/Archive/rearsusp/5.html

Thanks