#1  
Old 07-21-2020, 01:24 PM
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abefromen abefromen is offline
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Default Front springs?

Car is a '77 GP SJ with around 50Kish original miles.

It has been sitting for 25+ years and after getting it street safe and driving it, the suspension feels totally out of tune. And the way it sat it was obvious the suspension had sagged.

On smooth road it's fine and over minor road imperfections at low or highway speeds it isn't bad.....but go over railroad tracks or run over some bigger cracks and bumps and it's awful. It doesn't bottom out, steering is tight, reponsive and the alignment was just checked and is spot on, but it should be way more comfortable than it is.

Putting on 4 new shocks didn't do anything and tires are new.

I went ahead and changed out the rear springs with stock replacements and it not only raised the rear up a bit, but the ride in back was vastly improved.

I then went ahead and took of the control arms off because the control arm bushings both upper and lower were very dry rotted. They were also pretty hard.

The main question is, I really don't want to change out the front springs because it's a real crap shoot with replacement springs. Already tried some off the shelf moogs but they were WAY too high and stiff so out they came.

I can install some spring spacers on the original springs to bring up the ride height but it makes no sense to not change the springs if they are shot...........OR was it the old dry rotted hard bushings that was causing the harsh, out of tune feel of the front suspension? They were not all worn out because it was still alignable, but they were cracked, dry rotted on the exposed ends and hardened. They were tough to get a drill thru them when removing.

New springs in the back took care of the ride quality back there but are the bushings the culprit in front more than the springs?

Hate to put it all back together with spacers on the springs just to have the same harsh ride over moderate road bumps and train tracks but I'd also don't wanna keep trying different springs, way too much work.

Oh and regarding springs, when I called Eaton to hopefully get the right springs the first time, they refused to reveal the spring specs to me for the springs they said I needed. I found that odd and I didn't buy from them.


Last edited by abefromen; 07-21-2020 at 01:35 PM.
  #2  
Old 07-21-2020, 01:59 PM
JLMounce JLMounce is offline
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The bushings will be a large part of your ride harshness issue. It's also going to improve tractability, especially over some of those harsher road surfaces as the suspension will deflect less. Going to new springs is a crap shoot with these things and there's definitely some trial and error involved with it unfortunately.

If you like the way the car sits right now, and the springs you currently have don't show signs of corrosion or anything else that could be a safety concern, I'd put those back in. If you want the car to come up in the front to match the back, I'd try a set of springs from the forum sponsor here in the stock height.

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  #3  
Old 07-21-2020, 02:14 PM
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abefromen abefromen is offline
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Quote:
Originally Posted by JLMounce View Post
The bushings will be a large part of your ride harshness issue. It's also going to improve tractability, especially over some of those harsher road surfaces as the suspension will deflect less. Going to new springs is a crap shoot with these things and there's definitely some trial and error involved with it unfortunately.

If you like the way the car sits right now, and the springs you currently have don't show signs of corrosion or anything else that could be a safety concern, I'd put those back in. If you want the car to come up in the front to match the back, I'd try a set of springs from the forum sponsor here in the stock height.
Car needs to come up in front 1" or 1.50" that's why I was thinking just to add a 1/2" steel spring spacer to bring it up. Springs have some heavier surface rust on them but nothing that appears will compromise anything in terms of safety.

I guess it stands to reason the hard control arm bushings must have something to do with the harsh ride up front over bumps etc.

I have read where some people replace rubber suspension components with poly and then say the ride is harsh. I would think this situation is similar due to the age of the bushings.

  #4  
Old 07-21-2020, 06:04 PM
JLMounce JLMounce is offline
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Yeah if you were riding primarily on the bushing sleeves, you'll transmit a good amount of NVH back to the driver in that situation.

If the front end needs to come up almost 1.5" I wouldn't hesitate to put brand new springs in it at the same time. You're likely going to get about that much height out of a set of stock springs. If you're so inclined you can also add rubber spring isolators to the new springs at the same time.

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  #5  
Old 07-21-2020, 06:46 PM
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abefromen abefromen is offline
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There was plenty of rubber still around the sleeves. no metal on metal or anything like that it just seemed to me the rubber was extremely hard due to age. I don't recall other control arm bushing rubber that I had to drill thru being so hard to drill out.

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