Hello, group!

About 6 weeks or so ago, I bought a 2004 Bonneville SE, in very clean condition. The vehicle is running excellent, and seems to be in great shape, mechanically. It was a company/fleet car, and was very well taken care of.

The vehicle has about 88,000 miles on it, and my opinion is that the suspension is probably due for some work, as the vehicle feels just a little too "floatie", or boat-like, at highway speeds. I suspect the shocks, which are the original factory-installed units, are probably just worn.

I'd like to ask what the readers of this forum would suggest I consider, regarding any reasonably priced replacement/enhancement parts, whether they be aftermarket or OEM.

I'm not looking to go over the top with the cost, or create some kind of Ferrari-wannabe race-track vehicle. I'm just looking to tighten-up what I feel is a slightly mushy ride a bit, for a more sure-footed feel, at highway speeds.

Thoughts/suggestions? And thanks, in advance!

GXP sway bars
GXP front STB
SSEi springs

You could also replace the rear shocks with Monroe MA822 if the stock AC Delcos appear to be going bad.

A rear STB is possible but has to be custom made

Finally if you want to upgrade brakes you could get either SSEi or GXP brakes (depending on what size wheels you have). I believe you have to have 17" and above wheels to fit the GXP dual piston brakes in.

Thanks, Brian, for the reply.

I had read elsewhere in this forum, that the GXP sway bars were direct bolt-ons, with good results, and that'* something I've made note of, for the future. Likewise, the GXP front STB swap is on that list.

The budget wont allow me to do everything at once, and I'm wondering what the safety and/or handling results would be if I worked toward a "package" such as you suggest, in a one-step-at-a-time approach. For example, if I used factory equivalent shocks today, would those shocks then still prove adequate/effective/safe with upgraded springs later on, or would I be better off going with a shock engineered for the SSEi springs now, while I still have the SE springs, with the intent to add the SSEi springs later?

Since I'm not looking for Lotus-like handling as an end result, I feel I can overlap the perfomance characteristics of the components a little bit, being cautious not to go overboard, as long as the combinations are safe. The sway bars and stabilizer should be ok at any time, but I'm more concerned about mixing/matching springs and shocks.

Are there shocks and struts that would tighten things up now, with the stock springs, that would still be good when mated to upgraded springs later?

You mentioned the Monroe MA822 shocks for the rear. Will they work with the automatic load-leveling compressor system? Any recommendations for struts, on the front?

Wait until someone else chimes in but the front struts and rear shocks are the same for all the trim levels. The only difference is the springs if I'm correct.

And yes the MA822s will work with the auto load leveling.

FE1 (SE) and FE2 (SLE, SSEi) are the same springs all around. the GXP (FE5) has different springs and rear shocks. the sway bar difference between SSEi (FE2) and GXP (FE5) is 1mm, the GXP is 30mm the SSEi is 29mm. in terms of the rear sway bars, the SSEi (FE2) is 17mm while the GXP (FE5) is 22mm.

they do bolt right in but you will need the corresponding bushings, front FE5 Part #25699778, rear FE5 Part # 25666235 they will run you about $44 from GM. i just bought them myself.

better struts for the front would be KYB GS2 unsure of part # but they have them at rockauto

This is all excellent info. Thanks!