Write-Up: 1997 Front Control Arm Conversion (to '98 - '99 style)

So I've been trying to quiet down my 1997 Buick Riviera SC (AKA the Clunk-A-Potamus),...and I've replaced about everything.

New struts
New shocks
New ft strut top-mounts
New rear shock top-mounts.
New wheel bearings
New tie-rod ends
Strut-tower brace,..............All to no avail.

Next was to replace the weak and rotted bushings in the front of the front lower control arms. But the '97 front bushings aren't available that I can find (and I even had engineers at GM looking for me),..and the replacement control arms also don't seem to be available. And even they were,..they were super expensive at $450 or so.

Dorman did make a replacement aluminum arm for the '98 - '99 models,...but these have a different front bushing (thank heavens). And I think they too have gone out of production,...so grab them while you can. I have one extra.

So I decided to buy some and convert my front sub-frame to accept them..

Here are some pics pf the relatively simple process.

First was to acquire the arms, the bolts and nuts,...and then some flat steel to make the brackets from.

The bolts you will need are 14mm hardened bolts (-6 I think. I believe SAE bolts are grade 4 or grade 8,..the higher number being the much harder ones that are often a charcoal color. But for metric bolts, I believe they grade them as -6 and -12. These are the softer, plated ones,..so I believe they' are -6).

They're 14mm diameter, and 10cm in length, (as measured from below the head to the tip). Although I think the bolt salesman referred to them as being 4" long. I also bought some locking nuts. I think they're called "Stowe Nuts" Or is it "stove". Anyway,...locking, but not "Nylock". You wont be able to find these at the local Lowes' racing supply,...you'll need to go to a nut & bolt place. I think 12mm is the largest that Lowes' and Home Depot have.

Here's a pic of the bolts.


Next the brackets. I first tried making a single "U" shaped bracket (and in fact used it for the drivers' side). But it was very difficult to make and have it be the perfect length,...and also I found that the front bushing needed to sit closer to the sub-frame than that bracket could allow. So separate brackets is the way to go. It also gives me more welding surfaces.

Brackets. They are not perfectly 90 degrees. The one that goes in front is a bit less than 90,..and the one to the rear a bit more. Not critical,...just like 5 degrees more or less as the sub-frame angles in towards the center of the car slightly as it goes forward.

The steel I bought was 1/8" thick and 2.5" wide. I bought 2', but didn't need that much. I bent it using force, a big hammer, and a big bench vice.

The holes are not even. From the ground,..the one in front needs to be about 1 5/8" up,..and the one to the rear about 1 1/2" up. Again,..because the sub-frame runs at a bit of an angle.



I started by cutting off the old brackets with an angle grinder ($15 at Harbor Freight).
(Drivers' side shown here)




Next I used a sand-flap wheel on the same grinder to clean the surfaces, then bolted the brackets to the control arm and installed the arm into the remaining rear bracket on the sub-frame. Then I held the control arm and brackets firmly against the sub-frame and tack-welded the brackets in place. Then I removed the control arm for final welding.
(Note,..I am an amateur welder, and haven't even read the welders' directions.)

Passenger side.


Then for a shot of aerosol undercoating.

Passenger side before.



Passenger side after.



It still clunks and groans when driving down the road,...but I think there are 4-5 less clunks now. I think the steering rack may be shot.

thats really cool!

Good stuff! Thanks!

Stuart, first of all, thanks. This write-up is a help.

I'm going to be doing something sorta like this but I'm going to get a 98+ cradle so it won't involve any fab work. I could really use another subframe anyway for other reasons. With the matching frame, there should be no reason the control arms wouldn't bolt right up right?

I definitely have some noises and such myself and I hope that This will help. I've changed my front wheel bearings and outter tie rod ends already. My sway bar links are newish. I have a strut brace also. These noises seem like they came along after most of that stuff anyway. When I get this frame, I'll also be replacing all 6 cradle mounts and all hardware. I'll also be upgrading my swaybar and hardware at the same time but if I get to all that before you figure youre issues out, I'll get back to you with results on the noises and stuff. It's really getting to me lately...

Yeah,...3 of the 6 retaining washers on my subframe mounts were missing. Rusted completely off the car.

I bought 4 of them from the dealer for $2.23 each. I replaced 2 of the 3 that were missing. It seemed like the last bolt was going to snap,...so 5 will have to do.

My subframe is surprisingly solid,...and the rubber bushings were soft and intact.

I think my noise is in the steering rack. I can push and pull on a tie-rod end and hear a cliunk. And I checked the rack mounts to the subframe and they are tight. So I suppose it is wear inside the rack.

That will have to be the next owners' problem. I've put a grand and a half in parts and easilly 3 grand worth of my time into a car that's worth perhaps $2,900.

However,... on the freeway now it is smooth and quiet. I only hear the clunks at lower speeds in th city.

I have an A/C compressor from morad to install,...and I'll be selling it.

Nice fab job man.

Question, can you feel this "steering gear" clunk in the steering wheel? Example: If you turn the steering wheel from center all the way to the right, does it clunk once? And on the return to center? Same question for turning left. Are you getting a little clunk on initial acceleration? Possibly a slight "rattle" you feel in the wheel going over uneven road?

The reason I'm asking this is because a worn out Intermediate Shaft will cause all of the above noises. Alot of people (technicians included) mistake these noises for everything but the I-shaft. It's rare that one goes bad in a Riv.....just tryin to cover all the bases. GP's, Monte's, Regal's, etc of the same year have this problem.

another question i wanna throw out there. does anyone know why GM decided to have 1 vertical bushing on the front control arm? i mean,Duckstu had no problem flipping it around,and it lined right up! how does it save space the vertical bushing?

I don't think it's a matter of space. It's a matter of that "puck" style sucking. What amazes me is they still use it (Cobalt, G5, etc). It will go bad, just ask GP owners.
Like the pic shows, the Control Arm drops out of that bushing. The rubber can also separate from the bushing causing the same effect. The horizontal style can't move. It really has no where to go. Only problem with that is, we (I) need to replace the entire Control Arm instead of just a bushing!

i bought bushings all way around for my 95. ill install them tomorow. ill be doing this mod as soon as i can find a pair of alu arms.maybe pick-apart.

robotennis61 wrote:

another question i wanna throw out there. does anyone know why GM decided to have 1 vertical bushing on the front control arm? i mean,Duckstu had no problem flipping it around,and it lined right up! how does it save space the vertical bushing?

All I know is that if there's a wrong way to do something, someone will find it...

that's the truth. the idea behind the vertical bushing I'm sure got cooked up at a late night CO cocktail party."herb,lets do something really different?"
I've been racking my brains and i cant see how it "helps" or saves space. somehow i cant fathom that GM would engineer these idiosyncrasies into parts,only to increase parts sales...

[quote="robotennis61"]that's the truth. the idea behind the vertical bushing I'm sure got cooked up at a late night cocktail party."herb,lets do something really different?"/quote]

A-MEN!!!

so how does the car ride now duckstu?

Very comfortably,....still.

NO noticable increase in road-noise (NVH).

Of course having 16 or 17" wheels with ,...what? 70 series tires? keeps everything completely insulated.

Comming out of my Subaru STI,...the Buick seems to drive like I'm swimming in a pool.

I gotta believe some 17" or 18" wheels with some summer rubber would transform the car completely.

@ duckstu, yap! im pretty sure the 98-99 style would fit my 95? i seem to recall this to be true. how are the welds holding up? after the preliminary instal,did you go back and reinforce with gussets or something along those lines?

robotennis61 wrote:

@ duckstu, yap! im pretty sure the 98-99 style would fit my 95? i seem to recall this to be true. how are the welds holding up? after the preliminary instal,did you go back and reinforce with gussets or something along those lines?

The '95 should be similar to what my '97 WAS. You'd need to do the same conversion if you anted aluminum control arms.

But I wouldn't bother if I were you. The bushings for your control arms are redilly available, and the Riviera is so many light-years away from being a performance car that a minor upgrade like the control arms will never be noticed. The only possible benefit might be decreasing un-sprung weight to improve the ride over choppy pavement. But I doubt the weight savings is all that much.


The brackets I made are MUCH heavier in guage than the stock stuff. And I over-welded it.

Also,...the rear bushing takes most of the load. All os the side to side load in a turn is taken up by the rear bushing. The front bushing only gets pulled inward (durring accel) and outward (durring braking).

I have no concerns about the sturdiness of the brackets or welds. For sure it is much stronger than the factory ones,...and they held up fine for 175,000 miles. These will last three times longer than the rest of the car.

If I had it to do again,..perhaps I would use a thinner guage,....and make a square plate that connected the brackets across the top and tied into the top of the sub-frame.

Its not so much a search for lower weight,always a benefit, but to improve the handling of the car. the riv can hold its own against just about any car with only a few modifications.Replacing the bushings is job one! job two is to stiffen up the rear. there are no currently available rear sway bars stiff enough to solve the rivs greatest problem,its engineered ability to grossly understeer.the addco rear bar is stiffer than stock but it is still not as stiff as the front addco bar.the opposite in strengths would be better. on a front drive car the importance of the front bar isn't as important as the rear bars role in controlling the car.being able to control your car out of an exit with a little oversteer makes for a fast ride.too much and your out of control.too little and your pushing ...job 3 would be to eliminate the absolutly STUPID vertical bushing. do that and your bushing options begin to broaden......

robotennis61 wrote:

Its not so much a search for lower weight, (always a benefit), but to improve the handling of the car.

the riv can hold its own against just about any car with only a few modifications. Replacing the bushings is job one! Job two is to stiffen up the rear. There are no currently available rear sway bars stiff enough to solve the rivs greatest problem, its engineered ability to grossly understeer. The Addco rear bar is stiffer than stock, but it is still not as stiff as the front Addco bar.

The opposite in strengths would be better. On a front drive car the importance of the front bar isn't as important as the rear bars role in controlling the car. Being able to control your car out of an exit with a little oversteer makes for a fast ride. Too much and your out of control, too little and your pushing ..

Job 3 would be to eliminate the absolutely STUPID vertical bushing. Do that and your bushing options begin to broaden......

I have Addco bars in my Grand Cherokee (which by the way will flat-out smoke the Riviera in handling). And I'm sure a set would make a great improvement to the Riv. But without descent suspension damping,... the Riv will never handle well. After reading the forums,.. I gleaned that the Gabriel Ultras were supposedly the firmest available.

I bought and installed them all around (along with the up-rated HD strut and shock top mounts),.. and I can say they are scary soft. At a minimum the front application needs 20% more compression damping, and 100% more rebound damping.

The new lower control arms (with their firmer, horizontal front bushings) made surprisingly little improvement in the cars' handling. Actually,..none that I could detect.

For a car of it's size and weight,... to make it handle,... we'd need 17" or 18" wheels with lower profile tires. Mine wallows so much that I don't even attempt a fast corner. To get it to drive like a normal "old" car, I had to bump up the tire pressure from 30 to 33.5 psi.

If I was ever to try to make the Riv drive like a performance car,.. I'd start out with;
17" x 8" set of wheels, like these Bremmercraft wheels
245/50/17 tires such as these Michelin tires
Shocks and struts with 30% more comp damping and 80% more rebound damping. (Not available that I know of)
Stiffer anti-sway bars.
Permanently disable the traction control.

Keep in mind that to get power down when exiting a turn in a FWD car,....you need the front sways set a bit soft,...so that both wheels get traction. Especially on a car without a limited-slip differential.

The traction control in this car is an early attempt,... and it comes on way too early. With just the tiniest hint of a slip,..it's pulling power. In the snow (which is where you'd expect a benefit),.. I find the Riv drives much better and accelerates much faster with it off. It's a failure. Newer systems are much better and allow more wheel slip before they intercede.

But all this is an up-hill battle. The Riv was never intended to be a performance car. It's a nice, quiet gentlemans' coupe with plenty of power. Trying to make it something it's not will pro9ve to be an exercise in futility. And it's not just the design that gets in the way,...it's the lack of aftermarket support. If we could find a suitable shock and strut application from Bilstein (let's say),....then we could buy the wheels and tires for $1,450, .. and the front sway bar,...and have a run of stiffer rear sway bars made up (we've done that in the BMW 850i forum). Or we could drill new holes in the Addco bars. Slightly more out-board on the front bar,..and slightly more in-board on the rear bar. (I've done this on the rear of the Hummer H3 I had,..and also on the front of my Subaru bar. You just need a welder and a drill).

But in the end,..it would be a lot cheaper to sell the Riv and buy a '98-'99 Lincoln Mark 8 LSC. There's a big aftermarket for those. Chassis stiffeners, Bilstein coil-over shock setups, sways, tuning, big-brake setups, etc, etc, etc. And it's RWD,...so if you make big power,...you can use it.

I suggest just enjoying the Riv for what it is,... a comfy gentlemans' cruiser. I'm still amazed at how quiet it is on the freeway. It's second only to the BMW 750iL I had years ago.

1) i have bilsteins in the back. 2) do away with the rubber in the bushings and replace with poly or better yet nylon. doesn't matter if you have horizontal or sideways control arms. for me it just makes my bushing choices easier.
aftermarket support? who needs it? i have a brain..
there are hundreds of late 60s gtos that are successfully autocrossing @3200 lbs and do very well. any car can be made to handle well.
i can have a bilstein cartrige tigged into the mcpherson body quite easily.just takes $.

robotennis61 wrote:

1) i have bilsteins in the back. 2) do away with the rubber in the bushings and replace with poly or better yet nylon. doesn't matter if you have horizontal or sideways control arms. for me it just makes my bushing choices easier.
aftermarket support? who needs it? i have a brain..
there are hundreds of late 60s gtos that are successfully autocrossing @3200 lbs and do very well. any car can be made to handle well.
i can have a bilstein cartrige tigged into the mcpherson body quite easily.just takes $.

Of course. It's just that there's a ratio of cost, time, headache V.s. the return.

I have myself welded Koni and other inserts into old strut tubes. It's hard to do with Bilsteins as their bodies are often larger in diameter. So instead of simply cutting off he top of the old strut and dropping in an insert,... and then welding it in place,... what you end up having to do is cut off the bottom bracket and weld that on,...and then cut apart and weld on an upper spring perch. Quite a bit of work. And of course you need to keep everything aligned correctly and keep the welding heat away from the oil inside.

Once one has tackled the shocks and struts,... and the tires/wheels,.... and the sway-bars,.... you then need to deal with buying or fabricating a much bigger brake package.

Then to get more power down (either because of adding hp, or wanting to put power down when exiting a hard turn),.. you'll need to have the trans built and source an LSD unit.

Then the steering wheel is rather large and the steering over-boosted and the ratio too slow,....so you'll want to swap the wheel and the steering rack.

Then the steering rack and tie-rods are located behind the front axle instead of in front of it like on performance cars. This causes issues with bump-steer.

Then of course the car is rather long and heavy for performance driving. While it may be the same length as a '67 GTO (17.2 feet),...it is some 300 lbs heavier at nearly 3,800 curb.

Then you'd want firmer and slightly lower springs to go with those shocks.

So
firmer shocks
bigger sways
stiffer, lower springs
firmer and quicker steering rack
bigger brakes
more power (the easiest thing here besides the wheels and tires)
limited slip diff
built trans
better wheels and tires
suspension bushings
and by that time you'll be having trouble staying in the rather slick and flat seats,..so you'll want to install bucket seats or have some bolstering added in at an upholstery shop.



Not to dissuade anyone for trying,...and I certainly don't mean to knock the Rivi. I realize this is a Riv forum and people here like their Rivs. It's just that I've been down this road before,.. where I've dumped a lot of time and money into some car trying to make it something it's not. Then to hit a wall in the performance progression and sell the car at a huge loss.

I just don't wish that on anyone else.

The Riv does what it does very nicely (comfortably cruise at speed in quiet comfort,..and with a lot of style (extreme style for a GM product of that vintage). For the cost and effort you'd have to put into it to make it a performance car,...you could probably buy something else and have a performance car and the Riv both.

I wish you the best in your quest. And I'll look forward to reading about your cars' progress.

I've really enjoyed reading this thread, and have learned a few things. This type of exploration & fabrication is the only chance we have for improving the Riviera's handling and performance. Maybe we didn't get the desired result this time, but it's obvious the control arm pivots should be corrected on the earlier models - even GM knew it. As stated, the aftermarket for suspension upgrades is limited. It's up to us to figure things out and test it - if possible with some numbers to back up our modifications.

I think Stuart is generally correct in his assumption the Riviera isn't going to be a track racing star no matter what, although it's also true that anything is possible with enough work, as pointed out by robotennis. Four years ago, I was such a skeptic that I laughed at the Riviera Autocross thread. A member asked about the possibility of racing a Riviera, and my response was:

"We can improve our suspensions somewhat, but there will be no serious auto crossing with this car... A stock NEON will probably score a quicker time..."

Two years later, as we slowly found ways to change attributes of the soft feel of the Buick suspension (thanks to Jason and a few other members), I started to notice the car was doing things - things it shouldn't be capable of doing, like pulling over .9G lateral in a corner. This was measured by an accelerometer. One mod at a time (usually when something failed, it got replaced with a better one), the car felt firmer, more together, like one rigid piece. After testing several brake pad/rotor combos with F-body calipers, I found a recipe for decelerating 80-0 in around 4 secs, repeatedly. I started wondering if the Riv could hold its own against newer, more advanced "performance" sedans. So, I autocrossed her, and the results surprised me. Over 8 runs, I didn't hit a single cone, improving each time, and this was my first time driving autocross!

One of our members, Dirt Track Riv, was using his Riviera for off-road rally type events, and seemed to be doing well - I think he had at least one 2nd place finish. Haven't heard from him in a while, but his story was inspiring to me.

Stuart is right on about the wheels/tires. I went with 18"s and 45 profile - this actually felt too firm to me, so I will be doing a 50 profile next time. The Addco sway bar mod is, imo the best bang for buck suspension mod for the Riviera (besides the $30 STB bar). As you've seen with the Grand Cherokee, Addco does their homework on this stuff, and in my experience, it changed the handling character to be more neutral. Not too bad for a couple hundred bucks invested.

My next step for this car (if it lasts) is to do some hot laps on a road course, just to see what happens. I've driven a Honda Integra around a particular track a few hundred of times, so I know what I can do in that car, on that course. It will be interesting to see how the Riv stacks up. I am not expecting the Riviera to be a great track car, but I also did not expect it to do well at autocross. Imo, this car is more than a comfortable highway cruiser. It does have some potentially decent handling attributes that a few of us have managed to tap into. It's far from perfect - maybe "surprising" is the best description for what I've seen this car do.

I encourage everyone to modify if/when it's feasible, and to test and share your modifications any way you can, so that others can interpret the results and learn from it. It's up to us to try these things, because no one else is going to. I think there is a really fun car under the Riviera's OEM skin. I don't know exactly why that is, or how much fun can be had, but so far I've seen quite a bit of improvement for not too much money spent. Perhaps best of all, economy and ride quality weren't compromised that much, so I can still drive this car daily without problem.

Ok. wheels and tires would be the least of my worries if i were thinking of turning my riv into a track star. even a 16" tire with very stiff sidewalls can shine in the corners.

shocks,its just $.

there are alot of cars out there touted as "performers" that cant match the rivs speed.

my stock brakes work fine.they haul this big bugger down real quick.even after heavy use.in Vegas where the days in summer can reach 118 + i don't feel the brakes fading.sure i haven't auto crossed her,don't plan to,i know what shes for,but I'm not worried about stopping power.

power to the ground? its not been a problem that i can complain about.sure,she a little slow in spooling up out the corner but i just mash the peddle and away she goes.course she begins to push but that was how she was engineered.i have a rear sway bar solution,twice as stiff as the addco in the works,and it should be a doddle to install.

a smaller steering wheel quickens things up.

bump steer? no substitute for driver corrections i suppose.

weight is always an issue..sigh..but we all have our little problems.

springs? i have a set of custom made CCS springs that didn't turn out to be as short as i wanted,gaff on their part,but are night and day over the stockers.

bucket seats? why not? I've seen guys go out and buy a $80 thousand dollar corvette and swap em out. butt like i always said,"if you can control your ass,you can control anything and the world will be yours my son" you can quote me if ya want.

modding your car is fun.money? that's all it is. to do something and succeed at any cost when everyone cries nay is something.again.I've seen guys start out with porsches go out of their way to transform a perfectly good package into something better.sometimes not. c'est la vie...

$s for $s i haven't spent that much. i place a greater value in the long nights crawling under the car getting things right.

the days and nights spent dreaming about modifications and possibilities,Riviera or not,...priceless!

Awesome rovbo.

I'm looking foreward to seeing what all you come up with.

And I know just what you mean with Corvette seats. They are some of the worst in the industry. Not only do they lack any meaningfull lateral support,..but they break down in about 500 miles.

I replaced the Recaro seats in my Subaru STI with the ones that come in the Mitsubishi Evo VIII (also recaros). Even still, there isn't enough lateral support at the track.

So to help things out, I use a device called a "CG Lock". It attaches to the seat-belt buckle and makes it a one way buckle. After clickingthe buckle in,...you can pull up on the shoulder section of the belt and it will cinch the lap portion in. I find it allows me to relax my legs. Instead of using my knees to stay in the seat,...I can just use them to operate the pedals.

One of those might help in a track day or autocross.

duckstu wrote:

I replaced the Recaro seats in my Subaru STI with the ones that come in the Mitsubishi Evo VIII (also recaros). Even still, there isn't enough lateral support at the track.

So to help things out, I use a device called a "CG Lock". It attaches to the seat-belt buckle and makes it a one way buckle. After clickingthe buckle in,...you can pull up on the shoulder section of the belt and it will cinch the lap portion in. I find it allows me to relax my legs. Instead of using my knees to stay in the seat,...I can just use them to operate the pedals.

One of those might help in a track day or autocross.

Good thinking, Stu. There's nothing like the feeling of security and control you get by being cinched in tight behind the wheel. My first belts were in a 3-year-old '51 Henry J. Bought them the same place I got the one in the stock car I drove for awhile. First time it really paid off on the road was when a blew a rear tire at 70 in my '53 Buick Special. That was a bit of a workout, but no real problem. There were other times, like when I demolished a Studebaker doing a multiple roll and came out without a scratch or bruise. Which brings up the other reason being cinched in good matters. When your belt stays loose until you hit something, you move forward rapidly and then hit your belt at, say, 50mph. That causes a lot of unnecessary injuries, and has been known to kill people.

Quote :

When your belt stays loose until you hit something, you move forward rapidly and then hit your belt at, say, 50mph. That causes a lot of unnecessary injuries, and has been known to kill people.

That's because your head keeps moving at 50 mph with nothing to stop it. It's why a few fellow drivers and I are looking into buying a used HANS device right now.