Suspension gurus! Opinions, advice and criticism requested

[Tanglefoot]

My car ('90 n/a 240 - totally stock) is in some serious need of suspension attention. The rear is getting hammered on almost every bump that I drive over, and the exhaust system is in jeopardy of getting torn off on my driveway entrance (which happens to be a 20 degree angle of asphalt). This is without anything in the trunk or people in the back. It gets much worse with any weight in the car.

Now, I'd like to fix this. My requirements are simple (and thus make things much more complicated). I cannot lower the car. The areas that I drive have terrible roads, my driveway entrance is awful, and I tend to carry heavy things on a semi-regular basis. I am also fairly broke. The absolute most I can spend on this is $500. I would much rather the options in the $200 range.

I would love to have a sportier setup at the end of this, but that may be asking a lot. I have been looking on IPD at Bilstein HDs and overload springs. I also searched on here about the options of mid 90's Suburban front shocks as replacement parts. Can those be used safely with overload springs? Is that too much for a DD? I know I should prolly replace bushings and such as well. Can I do that myself, or do I need a shop with a press to do it? I have basic hand tools, floor jack and jack stands.

Suggestions?

[tryingbe]

What are you looking for?

Smooth ride or stiff ride?

[Tanglefoot]

Well, at the moment, I'd be happy with not bottoming out everytime I hit a bump :lol: I wouldn't mind stiffer than stock, but I also don't want to feel every pebble on the road.

[tryingbe]

Then get the Blistein tour class struts/shocks and over load rear spring with new strut mounts and with whatever left you can get some new bushings.

[volvo940tuner]

Bilstein HDs ftw

[towerymt]

How bad are the large trailing arm bushings (the ones pressed into the flanges on the axle)? Those could be worn out if the back is sagging. FCP sells Boge bushings for about $17ea and the special tool can be replicated for about $15-20 in parts from a hardware store.

[Spac]

Sounds like some Bilstein HDs should be your first step.

Then some wagon rear springs from a wreck if you still need help.

It won't be confused with a properly set up rac car, but it will solve your problems.


And make sure that the bushes, ball-joints and tie-rod ends are in decent condition. Towery is right about the torque arm bushes - they seem to die quite quickly when the shocks are crook. When/if you install the new ones, tighten them while the car is at ride height, NOT with the rear axle dangling in the breeze. If they're tightened with the suspension at full droop, then they've got a considerable amount of tension on them almost all of the time - so they don't last at all well.

[Tanglefoot]

How bad are the large trailing arm bushings (the ones pressed into the flanges on the axle)? Those could be worn out if the back is sagging. FCP sells Boge bushings for about $17ea and the special tool can be replicated for about $15-20 in parts from a hardware store.

What should they look like? I've never looked at them when they were good, so if it's not flamingly obvious that they're toast, I'll miss it. What's the special tool I need? I do have the Bentley manual, which lists tool numbers, right?

Sounds like some Bilstein HDs should be your first step.

Then some wagon rear springs from a wreck if you still need help.

It won't be confused with a properly set up rac car, but it will solve your problems.


And make sure that the bushes, ball-joints and tie-rod ends are in decent condition. Towery is right about the torque arm bushes - they seem to die quite quickly when the shocks are crook. When/if you install the new ones, tighten them while the car is at ride height, NOT with the rear axle dangling in the breeze. If they're tightened with the suspension at full droop, then they've got a considerable amount of tension on them almost all of the time - so they don't last at all well.

Yeah, at the moment I'm thinking Bil HDs and overload springs. I wouldn't mind the back end raised up a bit. I know, I know, contrary to all performance. However, the back of this car has almost always dragged a little. Thanks for the tips so far!

[Tom Wiley]

I have Bilstein TC's. Not recommended.

[Kevin Hawkinson]

What should they look like? I've never looked at them when they were good, so if it's not flamingly obvious that they're toast, I'll miss it. What's the special tool I need? I do have the Bentley manual, which lists tool numbers, right?

For checking them, you'll want a long prybar of some sort. With the rear in the air, if you can lift the axle up from the trailing arm with the prybar (more than 1/4"), then you need new bushings.

The special tool to press out these bushings is like a big thick tube with hefty endcaps and a big gnarly bolt.

Alternatively, if you don't want to make or buy a bushing press tool, and if you can figure out how to get all the old rubber out of the metal bushing sleeve, you can do the poly bushings. Get them from Dale.

[Tanglefoot]

For checking them, you'll want a long prybar of some sort. With the rear in the air, if you can lift the axle up from the trailing arm with the prybar (more than 1/4"), then you need new bushings.

The special tool to press out these bushings is like a big thick tube with hefty endcaps and a big gnarly bolt.

Alternatively, if you don't want to make or buy a bushing press tool, and if you can figure out how to get all the old rubber out of the metal bushing sleeve, you can do the poly bushings. Get them from Dale.

Ok cool. I'm putting in engine mounts tomorrow, so I'll try to check the bushings then. As for the poly, what are the pros and cons? They're stiffer right? Do they last longer? Are they noisier?

[klr142]

Regarding rear springs for your suggested use and price range, just grab some rear springs from a wagon and toss them in, maybe cut a coil or coil and a half off the top of them first to get rid of the lifted look and bring it back to stock height, but stiffer.

Regarding shocks, do NOT get the Bilstein HDs for the rear of the car, they will not be up to the task you're asking of them. They may do ok, but I doubt they'll stiffen the car up much or keep it from bottoming out if you're already doing so. Well, I guess that depends on how blown the rest of your stuff is. They'll be an improvement over stock/old, for damn sure. For the price, I'd probably just grab some KYB Gas-A-Just rear shocks, or the Boge/Sachs TurboGas rear shocks.

There's also trimming the first bump off of the rear bump-stops too, so that they don't come into play so early.

[Janspeed]

bottoming out has little to do with shocks.
if it bottoms out your springs have sagged. It's the springs that keep the car up and level.
A worn out shockdamper makes the car bounce and the suspention tramp under acceleration

There is however an exception: if your car has the self levelling Nivomat shocks and you replace those with Bilsteins then the springs will be too soft! (no fault of the bilstein)
The Bilsteins are designed to work with the stock or harder springrate and not with the ultra soft springs that belongs to the Nivomat setup.

[klr142]

Basically, yes, but, we're talking 240 here(no Nivomats), AND, a shock that is stiff on compression, and gas charged will ADD to the spring rate, as well as make it harder to bottom out the suspension due to more resistance to compression.