Can my suspemsion springs wear out??

sizemoremk

Registered User
1990 auto, all stock....

I was replacing my water pump this past weekend, and had it on jackstands (all fours) as I went ahead with IRS bushings since I was already dirty.

Anyways after a couple days on the jackstands, it road alot better than it has in awhile, but the next morning it seemed to ride poorly again...

I've been told by several shops that my shocks are just fine. I checked all the suspension bushings, and most looked OK, and I could see nothing that appeared loose in the rear end.

I am wondering if the springs have just aged to the point that they no longer hold the car up well enough?

I have replaced nearly all the bushings in the front end along with upper control arms, etc. and now the rear IRS differential bushings.

My ride kinda sucks alltogether... any suggestions???
 
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Springs do wear out over time. Even if they don't break, they will lose the ability to "rebound". Basically the same way the springs in an old mattress no longer provide support. If you are in the market for springs, check out www.shox.com All the aftermarket springs will lower the car to some degree, but that actually provides better handling without sacrificing ride comfort (unless you go with an aggressive lowering package). You may be able to get stock springs from a dealership, just be sure they are the springs for an SC and not a "regular" T-Bird.
 
If the springs are worn, there will be a visible drop in the car height. Also, you should do the bounce test on each corner to see just how good the shocks are working. With the car on the ground, grab a corner and push up/down with all your strength and get it going real good, then let go and count the number of bounces before it stops. Should be no more than 1. Also, shove it side to side, fore-aft, all around. It something is wrong, it should show up as you push it around.

Also, if the car seems to be tracking wierd, which could be part of your poor ride, check the rear wheel alignment. Did you torque the suspension parts to specifications? Did you do anything to the front?

Interesting that you had the car on 4 jackstands to replace the WP :confused:
 
I said I went ahead and changed the rear IRS bushings, thats why the 4 wheels up....

The spec on the IRS bushings was 30-40 ft pounds, so i did 35..

I've bounce tested em in front of the shop guys, and of course did it myself, and I get it boucing good, let go and it goes back real quickl and doesn't bounce.

I had it on a lift at the hobby shop today and re-inspected all the bushings and all seemed fine...

Its been aligned recently, and the front upper contol arms, and a few other front bushings that were visibly worn have been replaced.

I can try to move each wheel back forth and side to side and wheels seems to have no play in them at all...


I don't want a lowered car, already low enough, and I woudln't want to replace perfectly good shocks either...

I know something aint right, cuz the SC I used to have rode alot better than this.

Thanks guys, any other ideas???
 
sizemoremk said:
The spec on the IRS bushings was 30-40 ft pounds, so i did 35..
For a suspension component, that sounds a little low. Here's what Haynes has, in ft-lbs:
Rear suspension:
Upper control arm to frame: 50-70
Upper control arm to knuckle: 118-148
Lower control arm to subframe: front: 184-229
Lower control arm to subframe: rear: 25-170.. (I think thats a misprint, I think they mean 125-170)
Lower control arm to knuckle: 118-148
Lower control arm to toe compensator link: 118-148
Shock to upper mount: 27-35
Shock to lower control arm: 110-120

All of my fronts were in the 100+ lb range. On the front lower arm, there is an alignment bolt which is spec'd at 96-110 lbs. If it isn't tight enough, the camber can get wacko and if its off by just the smallest amount, the wheel get cocked sideways, and the car wanders all over the road and the ride feels funny. I don't know if the problem you're having is the same, but it may be worth a look.

Also, did you lift the arm with a jack to normal ride height before torquing the bolts? They suggest you jack up the control arm until the car just starts to lift from the jackstand, then torque the bolts/nuts.
 
It was these bushings...

http://www.mn12performance.com/mn12parts/diff_bushing/IRS100_install.htm

It said nothing about how far to jack it up... but it rides the same as it did before I did this, I was hoping these bushings were my problem...

I just thogut it was strange to get such a good ride the night I changed em, then the next moirnig it felt just liek it used to....

If I get the shortest lowering springs, will I have to change shocks?

I wonder what Ford wants for a set of stock ones if avialable???
 
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