TheExaminer

Just replaced my shocks and struts hoping it would smooth out the ride some. Helped a little, but still not enough. Every small bump rattles your skull and every other bone in your body. I also hear a mysterious, very small metal on metal knock sound coming from somewhere in the back sometimes, but I can't tell where it is. Would changing all the bushings in the suspension front to back do much for the car? Autozone has a full kit for $144 I see.

92 Formy L98 BTW....

SOCAL-Z

I am doing all my bushings right now on a 87. I would say yes after seeing what they looked like on my car all worn out with cracks and some of them even falling apart. Check Amazon.com price for the bushing kit.

TheExaminer

Yes, only $106 on Amazon, thx for the tip. The only ones I'm worried about messing with are the lower control arms in the front. Don't like messing with those springs, I think the book says to put a jack under the control arm to support it while taking the bolts out. I'll have to take a closer look at that, there's got to be an easier/safer way. BTW, let me know what kind of results you get with the change if you don't mind.....

SOCAL-Z

I sure will.

JamesC

iTrader: (5)

It's possible that the kit (or at least similar versions) may contain pieces you don't need. You might be better off in purchasing what you require a bit at a time.

JamesC

gt4373

TheExaminer

Yeah, that crossed my mind, especially looking at Rockauto. I'll have to go through the picture of the set and see what's there. There were a few pieces I couldn't figure out what they were.

Scorpner

iTrader: (4)

Not knowing what you have on there now, I'll throw some things out there that can cause a harsh ride.

• The wrong pairing of shocks/struts vs. springs.
  
• After-market suspension parts like double poly rear LCA's.
  
• Poly bushings instead of stock rubber.
  
• Low profile tires on large rims.
  
• Lowered suspension.

Noise can be caused by:

• Double poly rear LCAs (can cause binding).
  
• Loose spherical bushings.
  
• Poly bushings instead of stock rubber.
  
• Worn strut mounts.
  
• Transmission mount.
  
• Bad sway bar end links.
  
• Loose shock/struts and/or suspension bolts.

I'm sure there is more but I would exhaust the common methods of troubleshooting, or even take it to a good mechanic before randomly replacing things. That said, they are probably old enough to warrant automatic replacement. IMO, the bushings should have been checked and/or replaced when the shocks/struts were changed. The strut mounts should be replaced if they are not newer.

It is possible to remove the front lower control arms via the strut mount but that requires popping the spring out the side. By the time the arm is lowered there isn't as much tension on the spring but you still don't want to be in front of it.

Then the bushings need to be pressed in using a bushing press you can rent from an auto parts store. Taking them in to get pressed out via a large floor press doesn't work that well because the control arm doesn't fit. I might try the Del-A-Lum bushings next time but they are expensive.
Example of press:
https://robrobinette.com/images/S200...oint_Press.jpg

TheExaminer

Yeah, I knew I'd need a bushing installer. I just replaced shocks and struts with AC Delco gas charged, should be equal to OE. I did not replace the strut mounts, they weren't perfect, but not too bad either and didn't want to incur the extra expense right now. As far as I know the springs are original, and the car is definitely not lowered. If there was a spring change, I have no way of knowing, only had the car about 18 mo's. Also, as far as I can tell, this car still has all the original bushings, they are in tact, but show age and cracking. Trans mount is ok, just had that off a few weeks back, and replacing the end links was part of my bushing project when I do it, although honestly they don't look too bad--but they may be dried out and stiff. I may need new tie rods because when I turned the wheel lock to lock to bleed the steering system, it sometimes made a metallic popping sound at extreme right (I think it was right). Not a repetitive popping, but a one time pop when lock was reached. Ball joints seem ok, no movement, but replacing them wouldn't be hard if I get to this. No loose bolts that I know of. Rear trailing arms are original, er, at least one of them is, the other is 4th gen, but I have the original one if needed. Wheels are original GTA 16" cross laces. This car rides like absolute crap, even though it handles nicely in corners after the S and S change. I know some of that is just thirdgen tech, and I can live with that part of it because I love these cars. But there's no way this car rode this harshly when new, just no way.

ambainb

Noise in rear could be a few things.. my money, check the sway bar end link brackets, where the bolt to the car.. the loosen up for some reason and knock .. usually when pulling in a drive way.

Scorpner

iTrader: (4)

Hmm, nothing that you posted really sticks out as something that would contribute to the harsh ride that you're experiencing. A lot of people here go with after-market parts and larger wheels which can affect the ride quite a bit. I would not add poly bushings at this time as they may contribute more ride quality and noise issues, making it more difficult to diagnose. If you do go with poly try to get ones with grease-able fittings with the passages that allow the grease to flow inside. That is just my opinion though and there may be something that I'm missing.

I would give the strut mounts more importance though. I had one that used to pop whenever I jacked the car off of the ground and also when it was set it back down. When I removed them I found that the rubber was separating in one of them and you could only see that when the car was set on the ground. Many times when you take the strut cap off, the car is already on jack stands or a lift. The inside of the stock strut mounts are basically a giant rubber disk with a bearing inside (that also has a tendency to freeze up and possibly bind).
If you do end up with the springs off of the car try articulating the A-Arms to see if they are loose and/or difficult to move and/or even bind. the rears should be easier to check as the springs will drop out when allowed to extend all the way down. Recheck the shock and strut nuts while it's on the ground. Could also loosen and re-tighten the sway bar mounts and links while it on the ground as well in case they are boosting the suspension.

Could maybe be a broken spring? They are sometimes difficult to see. The OE springs do differ quite a bit (Ie. IROC/WS6 vs. standard) and you can tell by the thickness of the front coils and also the sticker/band which is often still readable. Your info says that you do have a WS6 so there may be a difference in OE shocks/struts available. The last time I purchased standard shocks there was no differentiation in part numbers between IROC, standard or V6 options which I thought was odd. I don't know how much that would matter as far as ride quality goes but that's the only other thing I can think of off hand.

Oh, I would go with poly end links, they don't seem to affect the ride as much while taking up slack that I've noticed with the rubber end links. Good idea on checking the end link brackets too.

TheExaminer

Ok, that's helpful info, thx for taking the time! I don't think I have a broken spring,but I'll give it a look. The rear will be easy to check if I change end links. I have a set of 4th gen spring cushions I want to put in anyway. I had thought about putting 4th gen variable rate springs in the rear to smooth out the ride some. But you think poly bushings would actually make the ride WORSE?

ambainb

I would think so

Scorpner

iTrader: (4)

To be honest, I'm not a mechanic but I've been reading the threads on here since 2005 and there hasn't been anything consistent on ride quality. It's been mostly about performance.
One thing I do think is important is to only change one thing at a time.

I actually do think that the rear can cause a lot of harshness due to the weight difference (lighter possibly more sensitive to changes). But again, it is important to have the springs and shocks matched or they will fight each other. My guess is that's where your problem is unless the original bushings are totally shot.

If you were to have rear LCAs with polys on both ends then yes they will bind because the OE LCAs were designed to flex a little bit. Even the later GM LCAs with the harder rubber were shaped differently. If you imagine the car tilting in a turn you should be able to "see" that they need to twist a little. Ie. the body twists but the axel stays in place on the road. Polys do not absorb shocks, or flex like the originals do. Rubber will be more forgiving if you're trying to reduce harshness.

TheExaminer

So I've got those new AC Delco S & S, which is close to what came with the car, and the ride was actually even worse before I made that change! How can I check the springs? What would I look for? I can't imagine the springs have been changed, but you never can tell. So you think the 4th gen springs in the rear would help? For all I know, the bushings COULD be totally shot. 23 year old car? Wouldn't be out of reason....

TheExaminer

Here's a closeup of the bushing in the RTA that isn't on the car right now. I'd say it's pretty representative of the overall condition of all the bushings. They look about like this. What do you think?

TheExaminer

"Even the later GM LCAs with the harder rubber were shaped differently."


Yip, my 4th gen bushings are star shaped.

Scorpner

iTrader: (4)

Well, as I was saying. The last time I went to buy struts and shocks, they didn't differentiate between WS6, standard, or even V6 shocks and struts. So unless you were able to verify that the shocks and struts that you purchased are matched to your springs then that could be contributing to the harsh ride that you're experiencing. So if the ones you purchased are “close,” how close are they and are they actually a good match for your springs? Keep in mind that the WS6 package was the highest performance package and will be more stiff and probably will have less room for variance as far ride quality goes. (Ie. More difficult to dial in with the current availability of replacement parts.) One of my Thirdgens rides rough while other people with the same set up says theirs are fine so there are differences between individual cars and peoples perceptions as well.
If you search online you should be able to find information on how to match the spring rate with shocks/struts. So if you can find out what your shocks and struts are rated for and then compare that to what your stock spring rates are you would know if what you have is going to work.

The tag on the springs look something like this:
http://restorationpartssource.com/st...Y3925817_t.jpg
Below is some info on what the spring rates are via the tag numbers. There used to be a complete chart but I cannot find that any longer.

https://www.thirdgen.org/firebird_spring_rate/
https://www.thirdgen.org/forums/susp...og-5660-a.html
https://www.thirdgen.org/forums/susp...ring-rate.html
http://corner-carvers.com/forums/showthread.php?t=17707
Here is an example of matching struts/shocks to springs but I haven't seen anything for Thirdgens:
http://www.maximummotorsports.com/te...ing_rates.aspx


From what I've seen, the rear springs often have the same part number. Fourth Gen rear springs may be the same. I don't know why you want to swap to a different generation of springs or any part for that matter before straighting out your ride issue first. As I was saying, I would want to minimize any differences until you get the harshness straightened out.

The RTA bushing looks worn. I don't know how loose it would be on your car though and/or if an accumulation of looseness among parts is an issue. I would take the car in to an experienced mechanic and have them evaluate the condition of the suspension components and if the bushings are loose or not. Otherwise you can try moving things around to see if anything is loose. For instance if you hear a clunk, then try to reproduce the noise so you can locate it.

Yes, you have the later RTA I was talking about.

TheExaminer

I got AC Delco struts (503340) and shocks (53010) under the "original ride quality" section on Rockauto. Checking AC's site, but don't see any info on what spring rate, if any, they are designed to work with. The ride has improved slightly since the change, just not enough. As bad as those old struts were, I'm not totally convinced they aren't the original struts! I mean, they were totally shot. I don't see a brand name on them, but there is a sticker that says "sensatrack" on it. None of the bushings I've come across is loose enough to move by hand, but that doesn't necessarily mean they aren't loose under heavy load.

TheExaminer

Found it, sensatrack is Monroe. IDK what kind they used at the factory.

Scorpner

iTrader: (4)

Yep, the Sensatracs are ok for stock like my V6 Camaro, but I wouldn't use those with WS6 springs. I'm guessing that the original ride quality shocks/struts are generalized parts to cover the entire range. I hope that I’m wrong but that's why I was saying that the last time I checked they didn't differentiate between the various versions of Thirdgens. You can see on the links how many different types of springs were available and stock V8 spring are very different than WS6, I wish I could tell you the difference in the actual rates but I'm sure it's quite a bit.

I would try replacing the strut mounts if they look like they are original (or old) and then make sure the rear LCAs are the same either way you go. See if that changes anything. Make sure too that you loosen up the front and rear sway bars and tighten them while the car is on the ground so they're not pre-loading the springs. Hopefully others will chime in with ideas as well.

TheExaminer

Just to make sure we're on the same page.... The Monroe sensatrack was what I took OFF the car this time that were totally shot. I went to the AC Delco site itself and put in my car info, and the only shock/strut combo that even came up was what I just bought, it didn't even offer me other choices. I can't imagine they could be so far off that they're causing all the trouble. Im more suspicious of the bushings, but I need to investigate getting OE type instead of poly--if that's even possible anymore--and not paying a mint for them. Right now I AM running one thirdgen RTA and one 4th. I'll put the other 4th gen on. I doubt it'll make any difference, but it's worth a shot. My panhard bushings may also be bad. Really the only ones that are any trouble to replace are the front LCA's. I need to invest in an internal spring comp. Loosening and tightening the links is a good idea too, and easy. I might pick up some new links this week at Autozone, want to put my 4th gen insulators in anyway, good excuse to do all that at once.

TheExaminer

Rockauto has the Moog 5662 front spring for $45 a set, says the rate is 748lbs. According to your link, 5662 is what the car came with. For about a hundred bucks I could replace all four springs and say the heck with it. Not sure what I'll do we shall see...... I need to know which spring is in the car NOW. Hopefully there's some marking that has survived.

Scorpner

iTrader: (4)

Yes, we're on the same page with everything but going to the AC Delco website to find the correct struts/shocks. But yes, that's the problem imo of not offering enough choices. They don't even offer as many tire choices for our cars any more so I guess we're lucky to find something that will even fit. They do make after-market adjustable shocks which might help with ride (definitely for performance) if you feel you need to try something different. That may be your best option since you have the higher end performance suspension. You might want to look into Strano for a matched set of (re-valved)Bilsteins and springs if he still does them. Keep researching here and other places to learn more about the options too.
Taking apart the front is a lot of work so I understand doing everything at the same time. Most everyone here has gone with polys but most are going for performance vs. ride quality.
Moog and TRW are good brands and I see a lot of people using them here. Be careful to buy from reputable places and also check quality as much as you can. There has been knock offs from China entering the market.

The spring compressor should be available as a free rental from a local auto parts store. Read up and be careful when replacing the fronts. I did use polys on one of my swaps but had issues with energy suspensions lining up so I switched to prothanes. (Also note the direction of the busings and bolts before you remove them.) If I had the money I would have went with Del-A-Lums. The springs need to be lined up with a couple of holes, iirc with one partially over one of the holes. Again search here for info or check a good manual.
I've been surprised how well the tags have survived on most of the springs I've come acrossed in the junkyards over the years, just be careful removing the dirt from them.
Oh, and on a side note subframe connectors may help stiffen the body as well.

TheExaminer

Well, I bought them from Rockauto, just went to AC to see if there was any tech info on them. I got these because as I understood it, this was the closest thing to what was on the car when it was new. I plan to do sfc's eventually, but I just don't have the money to be buying adjustable shocks and all that right now, I've pretty much got what I've got. I'll keep looking around at what I can change, and see if I can find what springs are on it right now.

Scorpner

iTrader: (4)

Ok, well either way what you have is better than what you had before. Yep, just giving ideas of the direction I might take with your goals in mind. I'm surprised more people haven't added to the thread.

TheExaminer

I think the idea of "ride quality" gets laughed at as a bit wimpy by all the performance enthusiasts who mod and race these cars. The last thing I'd want to do to my car is abuse it on a racetrack. If someone else wants to, that's fine, but I'm not. I just want it to be what it was when it was made, it's more a restoration. I MAY add a little HP to get into the 300-350 range, but that's about it. I just think it's silly to focus so much on performance and racing that you forget the car rides like crap when you drive it to work! LOL So yeah, I hear you, I'm surprised someone else hasn't piped in with some more ideas. I think an entire section of stickys and tech articles could be dedicated to getting the right suspension packages for different applications--including pure restoration. Part of my issue MAY be that I also own a 4th gen Camaro and an 07 Mustang, both of which probably ride better than a thirdgen simply by better technology. I hadn't driven a thirdgen since 1999 when I bought my current one in 2013. Part of it may just be that I've been spoiled by better tech, and have forgotten how rough WS6 thirdgens can be. I think that's part of it, but I also think there's room for improvement on my current car. Anyway, thx for taking the time to write everything you have, it's been helpful!

Scorpner

iTrader: (4)

Yes, I definitely agree with you on people wanting to modify without regard to ride quality. I think too that manufacturers probably carried a wider variety of parts up until a few years ago and now there would need to be enough of a market for them to bring back what used to be available. I do see peoples attitudes changing when it comes to modifying vs. keeping their cars stock. And I think that will continue as these cars go up in value. So a sticky may be a good idea.
300-350 hp sounds perfect imo. The 5.7 and WS6 package are great options and isn't lacking in performance by any means.

I've experienced the same kind of thing going from my mid 90's Bonneville to either one of my Camaros, so I know what you're talking about. I have driven some Camaros that rode really nice. One was an '85 Berlinetta with a 305, but it had very little performance potential in stock form. It had T-Tops and would have been perfect for car shows and cruises.
You're welcome, I’m glad I was able to pass on some of what I've learned over the years.

-=Z28=-

iTrader: (3)

These cars arnt town cars. they ride like lumber wagons right out of the gate.

TheExaminer

"These cars aren't town cars...."

Yeah, I think you may be right. Might go with new real rubber bushings and maybe variable rate springs in the rear and call it done. I'll check around a little more first...

TheExaminer

Got around to doing the front sway links today, and it was a good move. The drivers side link bolt was bent, and the passenger side link was so loose I could jiggle it with my hand! I don't know if it was always that loose of if putting the new one on the drivers side made it loose. I don't remember it being loose before, could be putting a new one on the other side unloaded it. Either way, they were shot. And on both sides the bolts were seized to the sleeves, I had to grab the sleeve with one plyers while I pulled on the bolt with another. Pretty sure the sway bar bushings need to be replaced too, I'll get to them when I can. Be nice to get a wonder bar under there too. So bent and loose sway links...."well THERE'S yer problem....." More upgrades to come I'm sure....

luvofjah

iTrader: (2)

I had good results with Founders rear lower control arms with 3 way poly joint that does enable them to twist without binding... Rode smoother than the other aftermarket ones with regular poly (that binds)...

Their LCA's are $ 83.90
http://www.foundersperformance.com/1...ceted_search=0

Panhard bar is $ 47.25

Both good if staying stock height....

TheExaminer

Ok, thx!

PurelyPMD

iTrader: (3)

Is it too early in your process to ask about recommendations on sway bar bushings & end links? I know I need to replace the dried/worn out end links on my 91 and want to go with something that will perform, but not kill the ride & look stock - so no red poly bushings (if you know what I mean).

Hope you don't mind me jumping in your thread but I think you'll be coming up to this point soon enough.

luvofjah

iTrader: (2)

Poly sway bar bushings and end links didn't seem to kill my ride, just tightened everything up, especially after the tired stock rubber... color is personal choice... black to look stock... I can see red easier (the shape it's in, to clean, etc...)

I replaced all the above with poly, the stock torque arm mount, Global West Del a lum A arm bushings and everything was great....

The things that may make a difference (have for some) are Poly engine mounts... I also got new smoother running Southbay Injectors, and that was not a problem.... but the poly trans mount and Spohn cross member mounted torque arm.... a lot of noise... going back to rubber mount soon for trans...

LarryD

Just my two cents but I just replaced everything under my 92 RS. It had the factory smooth ride FE1 suspension so I had to make sure the new parts were for that suspension for a similar ride (daily driver). Went with stock rubber in the front but poly in the rear. I did new coils as well as new bushing and ball joints, so as I said, everything. I don't notice too much ride difference but I am sick and tired of the poly squeak on every little bump from the rear. Will be taking out the polys and going back to stock rubber.

A note on the rear sway bar on the FE1 suspension. I think mine was 18mm. Nobody makes a bushing to fit it so you either have to go oversized or slightly undersized.

As for your knock sound in the rear, check your exhaust tail pipe and muffler. Really close in there and a worn hanger or poor alignment of everything will bang against the body or frame. Quick check is to reach under the back and wiggle the tail pipe around.

luvofjah

iTrader: (2)

Even with the proper grease, the poly squeals?

I did ball joints, new spring, Spohn & Alston SFF's (T-Top Car), Wonder bar, STB, Bilstein shocks / struts... seems quiet to me... minus the poly trans mount & Spohn torque arm... but working on them...

The car does feel night and day difference from stock to upgraded suspension...

LarryD

Yup, I tried the grease that came with them (Energy Suspension), added more, changed grease, left them loose a bit and nothing has stopped the squeak when I hit any kind of a bump.. I did not install the ES poly trans mount and glad I didn't. I did install the poly torque arm bushing.. Swapping them out as soon as I can get to it and will never use them again.. BTW, I did the wonder bar too...

My car would hop into the lane next to it on the free way it was so bad before I changed the entire suspension front to back.. I still have a bit of wander that corrected somewhat by adjusting the steering gear box.. Going to change that soon along with the rag joint.. Don't know the condition of the rag joint yet since it is hidden under the cover and I haven't taken it apart yet... After all, daily driver with 450,000 miles it got a little loose...

Next up, complete new interior (already have the carpet, upholstery, and headliner) and then a paint job to wrap up the rolling restoration..

TheExaminer

I just went to Autozone and got the heavy duty sway links, only $3.69 ea., the new front sway bushings I ordered from eBay, I forget who made them--but they are all rubber as far as I know, but they won't be here til next week. I ordered a new wonder bar for the front and variable rate coils for the rear just now. Hopefully between all this, it'll smooth me out some. I already notice a difference swapping in the new links in the front! I'm going to swap the rear links out at the same time I do the coils and 4th gen spring cushions.

TheExaminer

That's why the more I learn about poly the less I like the sound of it. BTW, I'm going to swap my rag joint shaft out soon too. I've had a replacement for several months but have been putting it off because it looks like it's going to be a pain to maneuver it out around the brake lines. Whatever that rubber section at the top is, it's split open on mine and whatever grease was in it has run out on everything over a period of years.

ambainb

Is ur car lowerd? If it is cut down the end links
I use spohn del-yadayada everywhere in the rear and i like them

TheExaminer

Ugh, not a chance. I don't like lowered cars, especially thirdgens. That's one thing that I have never understood. Makes it harder to work on too, dang near have to own a lift just to get under it.

ambainb

I here ya, some prefer the look, some want the wieght down just a little lower

TheExaminer

Yip, to each his own. I lean more toward resto than mod--generally speaking. I guess I'm more old school overall.

PurelyPMD

iTrader: (3)

Thanks guys, ordering!

TheExaminer

Got the new variable rate springs installed this week. New sway links on all four corners now too, along with a new wonder bar. So with all that, the ride has improved some. It's not the end all fix, but I can definitely tell a difference. New bushings will help even more I'm sure. So if you're wondering, yes, 4th gen variable rate springs will help take some of the harshness out of the thirdgen ride quality. It also raised the ride height about 1/2-5/8" or so in the rear, which some guys will hate but I don't mind. Restores it to its original level, or close, and gives it more of an old school hot rod look. I've always thought this car sagged a little on the back end. I also installed 4th gen spring cushions, some of the height increase came from that too I'm sure.

TheExaminer

Notice the big difference in the new and old springs while unloaded. I'm sure the new ones were taller in their own right, but the old had sagged too I'm also sure.

ambainb

Holly ****..m thos are the replacements? There that much taller? Lol what brand are they, mine were whooped too but never really set them next to my lowering springs

TheExaminer

LOL They are AC Delco, got em from Rockauto, about $56 or so shipped for the pair. I went with AC because my new S&S were also AC gas charged, and I figured they might work better together. They had Moog and a few other brands available for similar prices. Pretty sure those old springs were OE, they sure looked it, and so did the rusty isolators. So technically these aren't "replacements" because they are really more 4th gen than third. I'm sure it's a combo of a different gen of new spring and spring fatigue in the OE's that makes the difference. But I like the look, like it more every time I look at it. Besides, when the springs settle in, I'm sure they'll drop slightly.