1989 LTC load leveling air shock suspension....Adjustment

[porschpow]

So after putting in the new suspension in the front, the back was sagging, even though i put new shocks in the back, i put in MOOG 8805 springs in the back, which didn't do much to change the height at all.

I don't know if I should go for taller springs (loose the soft ride) or ...Is there an adjustment that you can increase the air in the back shocks???

[gadget73]

the height sensor is adjustable. On the upper control arm where the linkage hooks, you'll find a ball stud. There are 3 holes in the arm that the stud can go into. Its got a nut on the backside you have to undo to move it. The linkage itself is also threaded for fine adjustment. I believe its got lock nuts at each end, one of which is reverse thread, then you just spin the rod itself in the middle. I want to say moving the sensor up and/or making the linkage longer makes the car sit higher but that may be backwards. Just make sure you oil all that stuff before trying to move it.

[porschpow]

are you referring to the upper control in the front by where the compresor sits? my chilton manual doesn't cover town cars, just vics and GM's

[porschpow]

I am sorry, but I am just confused, is the height adjustment on the compressor or springs/trailing arms?

[IPreferDIY]

I'm confused too. porschpow, did you used to have air suspension in the rear but replaced the air springs with coil springs? And now you want to pump more air into the shock absorbers to raise the ass end? It sounds like gadget's referring to the height adjustment for the air springs, which I would think wouldn't do anything for a coil spring setup unless there's a way to plug the air lines into the shock absorbers.

BTW gadget, if you're referring to the height adjuster for the air springs, I had it backwards the first time myself. I don't know how the geometry of the older cars compares to mine, but the one on my Watts link requires the rod to be shortened to get the system to push the ass end up.

[gadget73]

rear upper control arm, above the rear axle. The sensor itself lives damn near center above the diff, the linkage arm comes off the sensor at an angle to attach to the driver's side upper arm.


The boxes never had proper air springs. We got coil springs with air shocks that were connected to a compressor, with a level sensor thats basically like the air spring cars use. Very possible I've got the taller/shorter thing backwards. Its been years since I fooled with it, and mine hasn't been hooked up in some time now.

[porschpow]

Oh so its right next to the t divider where the break line diverts right?

[gadget73]

Pretty much. Look right above that and you'll see a box with an arm sticking off, and a rod connecting that arm to the upper control arm. The adjustment is on the upper control arm. I think that moves it about 1 inch each way, for amounts less than 1 inch you can mess with the threaded rod linkage.

[porschpow]

i see the rod, i messed with "extending the rod" each side by three-four turns. It went up a little bit.

However, the end of the ball stud joint that goes into the upper control arm, I am having a devil of a time trying to loosen that nut and to keep that ball joint end still so I could keep loosening that nut, it's very difficult to do, but I am thinking I can "lower" this end of the linkage in the control arm hole, so that it is level if not a little higher than the front.

Just got to find a way to loosen that stud end nuts without harming the ball joint end

[gadget73]

i want to say its a nut on the inside, and you have to hold the ball stud with something. Not sure if ther is a wrench flat or what. I do remember it being a pain in the ass.

[IPreferDIY]

... The boxes never had proper air springs. We got coil springs with air shocks that were connected to a compressor, with a level sensor thats basically like the air spring cars use. ...

Ah. Another historical tidbit that's nice to know.

So after putting in the new suspension in the front, the back was sagging, even though i put new shocks in the back, i put in MOOG 8805 springs in the back, which didn't do much to change the height at all.

I don't know if I should go for taller springs (loose the soft ride) or ...Is there an adjustment that you can increase the air in the back shocks???

Something that came to mind was whether it might be useful to change the rear bushings if they haven't been done in awhile. I know when I did my front bushings, the front end was definitely sitting higher without having replaced the springs or shocks. I'm not sure how much the back improved after changing the rear bushings. I had adjusted the height sensor just slightly the wrong way, but my car still seemed level, so maybe the new bushings had offset the height sensor error. I wonder if your rear bushings might be worn enough to cause some sag.

[porschpow]

Hey so, I had a chance to fiddle around with it. What i can do, is pry something btw the rail and the nut as so to stop the thing from turning (since I can't use a vice grip on the ball end). I was thinking to move the ball studd to the lower spot (towards the ground) since it look to me that it sits at the highest spot

[jaywish]

You did move the thing to another hole before trying the adjustment screw. That is easier.

The shorter the rod the higher the car goes up.

[porschpow]

weird, ok, must be an optical illusion, either that or the springs are settlin, it seemd to me that longer I made the rod, the higher it went up

I tried to undo the bolt to make it go into a lower hole, towards the ground, but i need to find a way to hold the ball stud still while i try to get the nut off

[gadget73]

longer rod makes the car higher. THinking about it, when the back end of the car settles from weight, the arm on the sensor is pushed upward. If its lifted, the arm moves downward. If you want it higher, you move the arm upward to make it that way, either by making the linkage longer or moving the stud upward a notch.


I remember screwing with this on my car, laying under it with the car just sitting on the ground. I vented the air shocks and got stuck under the car. I was able to get out, but I had to pick the car up and scoot back several times to get there. You're not as fat as I am though, so you may fit.