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View Full Version : Revisit to suspension trouble....



fastsc92
06-09-2008, 07:26 PM
A few years back I posted a thread discussing some suspension issues I was experiencing. At the time I had a set of S/T lowering springs on my 92, mated with some cheapo KYB shocks. Not the best set-up out there but it was good enough for me. I had the springs for a few years and I could never get the front end to sit level with the rears. This was my problem.

When I installed the set, I got shorter end links for the rear sway bar. However, I never did anything to the fronts. Here is an old picture of how the car sat on level ground a few years ago. The front end sitting higher than the rear......
http://img.photobucket.com/albums/v325/fastsc92/IMG_0084.jpg

This year I installed a new set of H&R springs figuring that they have a lower rating and they are progressive for a better ride. After the install, the rears sit nice and low, and the front end still sits high. In fact, its 1/2" taller than before the swap. ( The rears however sit lower than the S/T springs and the gap is perfect..)

Now before I get a bunch of responces, here are some facts:
1. The car has had time to "settle" with the suspension, but the measurments are the same
2. ALL the bushings and control arms have been done in the front end, and there is no suspension binding
3. Measurements from the ground to the fender lip is 27" in the rears and 28" in the front. I'm not sure what size tires are on there now, but regardless, the car is not sitting even


So here are my thoughts....

I've been through the front end of this car nearly a hundred times, with no luck. The only thing that i can think of is that the strut rod is binding, causing the front end not to settle. I highly doubt this, endless someone can convince me otherwise.

OR

The front swaybar endlinks need to be cut 1.7" and rewelded.

Any thoughts to this long issue that's been a pain in my butt for years?

Mike8675309
06-09-2008, 09:43 PM
A

I've been through the front end of this car nearly a hundred times, with no luck. The only thing that i can think of is that the strut rod is binding, causing the front end not to settle. I highly doubt this, endless someone can convince me otherwise.

OR

The front swaybar endlinks need to be cut 1.7" and rewelded.

Any thoughts to this long issue that's been a pain in my butt for years?

I just checked my fronts. 26.5" from the ground with 245-45-ZR17 tires and vogtland springs 1.6" drop. Rear is 27.25"

Checked my 35th which is stock but old. Front is 27.75" and rear is 29"

Front swaybar links are factory on my 93 with the drop srings. The design of the sway bar allows it to pivot as a unit such there is no impact on the suspension loading if both links are the same length regardless of suspension position. It is the rear that are touchy... though mine are still stock in the rear as well.

The strut rod should not be able to impact things, but if you have poly bushings it may, especially of the lower control arm bushing at the subframe is poly. That joint needs to move as the suspension travels in an arc with the strut rod helping to position the shaft. If that bushing is not allowing the lower control arm to move the strut rod will fight that bushing resisting motion.

If you have someone with a different SC around, you and some buddies should push on the front fender and watch the motion of the front tire. Then go and do the same thing on your car and see if it moves.

something is holding the car up. Do you have stock shocks? i.e. there isn't a shock with a too long of a shaft that is holding things up?

Ddubb
06-09-2008, 11:07 PM
Do you have half of a tank of gas?
Anything loaded in the trunk when you are measuring ?
How are your rear spring isolators ? Worn out or nice and stiff ?

- Dan

Mike8675309
06-09-2008, 11:24 PM
if you mean me... all isolators are original. in both the 90 (stock suspension) and 93 (lowered suspension) the only things in the trunk are the spare and a jack. I dunno about gas. 1/2 in the 93... probably 3/4 in the 90.

For fast92sc... good questions.

fastsc92
06-09-2008, 11:26 PM
To answer some more questions.....

The links in the front are indeed stock length.

The control arms in the front are new, the uppers from Moog and the lowers from TRW. They both contain stock-like rubber bushings at their mounting points.

The Strut rod bushings are Moog and are a hard, blue plastic

The rubber insolations in the rear are new from Ford.

The shocks are KYB's on all four corners

The trunk is empty except for a remote battery box and my nitrous bottle. I'm fairly confident that the rear end is sitting at the correct height, I'm just wondering why the front is high.

As I said before, I'm not sure what size tires are on there now, some junk tires and rims from a LX while it's being prepped for paint. I think they are on the order of 26" tall. But regardless, the front is sitting much heigher than the back.

The car rides and handles normal, and if I push on the front end, it has plenty of travel. I've gone through things in my head hundreds of times and this one still has me stumped.......

Duffy Floyd
06-09-2008, 11:37 PM
When you did the suspension work did you load the suspension prior to tightening the pivot joints such as Shock Mount bolts, upper and lower Control Arm pivots, rear pivot joints too?

fastsc92
06-09-2008, 11:39 PM
Everything was snugged up when the control arms were on jack-stands. Therefore the weight of the car was on the suspension before everything was tightened up. There is no suspension binding that I can see.

Mike8675309
06-09-2008, 11:51 PM
Everything was snugged up when the control arms were on jack-stands. Therefore the weight of the car was on the suspension before everything was tightened up. There is no suspension binding that I can see.

If the jackstands were just on the lower control arms, all the weight wasn't in the right spot. It was slightly inboard which will not deflect the arms as much as if the car rests on the tires.

I would loosen all the bolts, and set the car down and see what it looks like after pulling it forward and back a few feet.

fastsc92
06-10-2008, 09:06 AM
I don't think bind-up is the issue here. I've tightened it before when it was on the ground, with no luck. I just chose jack-stands this time so it would be easier to get at all the bolts. I'll give it another shot and loosen everything, even the strut rod on both ends. Maybe getting the car on a pair of ramps will get the weight on there and also allow me to get at the bolts and nuts much easier.

Maybe my issue lies within the KYB shocks. They measured to be the same as the stockers when I took them out. The spring perkes are in the right spots and everything appeared to have the same dimensions.

XR7 Dave
06-10-2008, 09:31 AM
You are understimating the impact of what you have done to the weight of the car. Putting the battery in the trunk has 2x the impact because you took it away from one end and put it on the other. Add the nitrous. You removed AC so delete that, and I'm guessing that your new IC system isn't any heavier (probably lighter) than stock. Did you take anything else off the front end?

Also, how you orient your rear springs has an impact on ride height. I know the Ford manual says it doesn't matter how you position the springs but it does, IMO.

Having the car on jack stands is not at all like being on the wheels. It has to be on the wheels to load the suspension. Make sure you really loosen the bolts and then bounce the car to settle the bushings. They might not want to move now that they have set in one position and have been tightened that way. Also, it can take a long time for a suspension to really settle. Leaving a car with the front in the air a lot while working on it and leaving the back on the ground can contribute to a higher set in the front as well.

And then if all else fails jack the rear up, loosen all the bushings and retighten with the suspension fully relaxed. ;)

fastsc92
06-10-2008, 09:46 AM
I agree that some weight has been removed from the front end, but I was having this issue before the front mount, before the battery removal, and the AC is still in there besides the condensor.

The rear sits level on both sides, and at the moment, there is nothing in the trunk, the bottle only is in there for track nights.

When I had the S/T springs the height was ok, but the H&R springs make the stance much better in the rear. I think this is because the S/T springs are rated for 1.5" drop for a normal t-bird, not the sc, whereas the H&R's are the correct springs for this application.

The control arms and bushings are new, but I installed them at least 4 years ago, with maybe 2000miles on the components. They were tightened with the car on the ground. I would have guessed that things would have settled by now. Again, when I have a chance I'll try to loosen everything up and get it on the ground. I don't think I've ever loosened the strut rod bushings when doing this. I mainly focussed on the lower CA bolt and the lower shock bolt. The uppers I tightened with the arms in the level position.

Now once it is on the ground, whats the best way to get at everything, because access is limited?

XR7 Dave
06-10-2008, 10:05 AM
Another possibility is that the springs are actually made for a 4.6L application (regardless of how they were sold or labelled) as the 4.6 is heavier in the front.

fastsc92
06-10-2008, 10:27 AM
It could be possible. They were boxed as #51624 and also labeled as 51624 front and rears on the springs themselves. H&R states they are for SC and V8 models, whereas the 51623 are for N/A v6 lx models. I don't think this is the case however....

#51624
front spring rate- 310-385 lbs per inch
rear spring rate- 540-610 lbs per inch
freelength- 16.25" front, 12.00" rear

The freelength on the H&R's were longer than the length of the S/T's, but I'm assuming that's just in the design of the progressive spring.

ricardoa1
06-10-2008, 11:57 AM
Aside from what Dave said on the weight transfer, Advertised number sometimes do not give the same results. It is always best to get opinions of other results then going by the actual reading on the springs.


Very few springs will give you rake, most come lower in the rear. A tank of gas will make a big difference in height. It is easier to just raise the back and level out that way, as the springs settles it should give you an even drop.

Driving the car will also make the springs settle, big dips on the road will work out the springs and get them closer to their designed drop.