Write-Up: Installing a Front Strut Tower Brace (STB)

Here is one of the best bang-for-the-buck handling mods you can do to your riv. It's a strut tower brace (STB) designed for the 98-04 Cadillac seville STS, gm part# 25653157. You can read the entire thread about it at regalgs.org. Go out and get one of these STBs. It truly makes a notable difference. If you guys in the US can order if for 20$ + shipping, you have no reason not to order it right now.

Front end feel is greatly improved. The car feels much more composed over uneven pavement. Feels more comfortable going into turns at higher speeds. All G-platform cars should have come this way from the factory.

I think the guys over on the aurora board said it best:

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great. Not awesome, but definitely great. More tied down feeling in turns transmitting more of the tire feel up through our rather numb Magnasteer system. More connected feel over one wheel bumps. It makes it feel like a more expensive car. For the $18 plus shipping you just can't beat it.

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W O W . for anyone that appreciates handling mods.. Boy does this ever make a difference in front end feel!! going over bumpy roads, the steering wheel feels rock solid [...]. Its eliminated so much flex in the front end i feel like im driving a different car!!

Unfortunately for me it was not just a bolt on mod (though I suspect it could be for others). If you check out the aurora boards and the results of other riviera owners, for some people it fit with no bending and others weren't so fortunate. It will_not clear the brake fluid reservoir so you'll have to double bend the tabs a little bit to get some extra height.

this thing is fairly beefy. Here is a pic of the Cadillac Strut Tower brace (gm part# 25653157) as shipped




Here are the basic instructions on how to do this mod. It will take a bit of tinkering, based on your car. You'll probably end up having to play with it for 1/2 hour or more and remove it a few times to get the tabs bent just right.

1) remove the 2 innermost strut to body bolts.
2) Shim the STB using 1-2 washers to get enough height to clear the brake fluid reservoir. Keep in mind The 95-97 rivieras had a stud-and-nut type fastner at for the strut to body bolt. Shimming will probably be a lot easier for these models and may not require bending the tabs.

Although the holes lined up perfectly with the unbent STB, I had to use a dremel to widen the holes just slightly to get them to line up after bending the tabs.

3) screw the bolt back in and tighten to 35 ft-lbs



On 98-99 models, the bolt is long enough to support 2 washers. I don't think using 2 washers is very elegant and I'm sure it doesn't help with the force distribution...

Now you have about 1-2 mm clearance with the brake fluid reservoir. Any more and you'll have hood clearance issues.


Here is the final result



The hood still closes, and the bar leaves only a slight dent in the foam insulator, though it definately compresses the insulator (I don't really care if it does though, as I already damaged it a while back). As for hood clearance issues, I can't tell if there is any displacement, so if there is any it is less than 1 mm. I took some pics anyway.



Enjoy. Next write-up will be sway bars.

Hey Jason,
Nice write up. As far as clearance issues...is there a difference between the Series I and Series II engines?

I think you've convinced me. After I install the front/rear stabilizer bars and bushings, I'm doing this mod. Thanks for the contribution!

Aaron, do the STB first, it's simple, cheap, and takes 10 minutes.

I want to see what KYB struts + Adco stabilizer bars feels like, then compare to the STB install. And I'm taking more than 10 mins on mine. Thinking about making some custom inserts rather than using washers, painting the bar, etc.

the ride feel really does change, but its almost worth it just for the look under the hood. the red and black color scheme really sets the engine bay off.

Mine will be either black or body color (I have the paint already).

I've got mine. I think I'll do it body color on the Silver Arrow. I am going to see if I can get it to work on the '95 before I install it in the '99 and if so I'll get another one for it!

paint the same color as the s/c snout/housing (the grey ones not the tan) would look good too IMO.

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As far as clearance issues...is there a difference between the Series I and Series II engines?

nothing that would influence the installation. You'll have studs instead of bolts on the shock towers though.

I haven't look real close yet but I know the alternator on the '95 is larger, I'll look and see this weekend if it is going to cause a problem.

i dont think the alt is in line with the brace, but if the master cylander or brake resov. is any bit higher on the 95's then it may be a problem. you'll find out soon enough

Called someone on this at a junkyard and they wnated 70$ so i skipped it can anyone send me a link on where to get on for under 30$??

Will it fit my riviera??? its the strut bar??

No.
/thread

no. just look for the strut tower brace thread.

Just ordered one from my local "CADDYLAC" Dealership for 33$

I paid $36 tax included from the dealer.

jax95riv wrote:

I paid $36 tax included from the dealer.

i got one on the 14th of march FROM the dealer for 33$ and tax

My STB came in yesterday and I made a short-lived attemp at putting it on. Clearance from hood/m.c. is unknown yet because the holes do not line up. I have a 97 with the nuts at the top of the strut tower and it's about an entire hole-lenght off and I don't suspect it will be able to be adjusted enough to compensate. Have any of you encountered this?

I'm thinking I could enlongate the rearmost hold at the top to be able to move it enought to make the bar work. The brace its self doesn't look like it offers much extra metal to enlongate the hole there.

I'l take a picture of what i'm talking about since it's probably difficult to visualize without

all the pictures were takin with the bar in about the same place so the holes on the bar are too far inward and also too far apart front-back wise to fit. Ouch!

Since the bar braces the towers from the inside, I shouldn't compromise it at all by notching off the outter part of the stb's mounts right?

Mine was the same way. I had to elongate all four holes. Go slow and keep rechecking it as you grind it, or however you plan on elongating them. I used a 90 degree grinder air tool for mine. You'll get uncomfortably close to the edge. If I remember right, it's the outter inboard corners on all holes. I also had to put two washers under each nut to have clearence for the master cylinder. which means you won't have any threads showing through the nuts. But it does work.

well good luck mine bolted right up in less than 5 minutes but i do have a 98

98riviera98 wrote:

well good luck mine bolted right up in less than 5 minutes but i do have a 98

You didn't even need washers?

Are the bolts at the top of the tower movable at all?