Engine Cradle Bushings

[ckucia]

Has anyone experimented with different materials on FWD Cadillac cradle mount bushings?

the stock ones are made up of steel retainers with rubber inserts of varying hardness.

Been reading over on some of the Taurus SHO boards that those guys have been using aluminum and delrin replacement bushings. These supposedly tighten up the handling tremendously, although they do let by some noise and vibration - some people see the noise as minimal, others find it annoying. All of them agree that the handling improvement is pretty incredible.

Since the engine is still isolated from the cradle by the engine and transaxle mounts, I don't know if noise would be all that much of a problem.

Any opinions?

[ckucia]

Argh.

I should mention some background...

1989 Allante

Dropped the engine cradle to take care of a little rust. Rear bushings were shot. No longer available from GM. Front and middle bushings worn, but retainers rusty. Found a substitute part number for the rubber parts. All retaining bolts rusty to the point of needing replacement

Discovered that the spacing is the same between the cradle and the #3(unavailable) bushings and the #1 and #2, so figured I'd order the parts to use a front/middle bushing in the rear.

Hard parts for the front and middle bushings are also discontinued by GM.

(Just as an aside, some of these parts are shared by other GM cars (Eldorado, Reatta, Riviera...))

That is what leads me to try to find a replacement for the rear bushings. Perhaps I'll do some junkyard visiting, but it would be easier (since I have access to a lathe) to just machine out some aluminum ones, if they'd work. I'm sure any Cadillac in the junkyard from the same era is just as rusted out as mine was. I had the bolts soaking in WD-40 for a week just to get them loose.

[eehoepp]

Just a quick note:

The engine cradle bushings on my 94 STS look very similar to the cab mount bushings on my S10. Energy suspension sells urethane bushings for cab mounts. something's gotta work. Hockey pucks work well for pickup cab mount replacements, too.

Cheers,
Eric

[ckucia]

Originally Posted by eehoepp

Just a quick note:

The engine cradle bushings on my 94 STS look very similar to the cab mount bushings on my S10. Energy suspension sells urethane bushings for cab mounts. something's gotta work. Hockey pucks work well for pickup cab mount replacements, too.

Cheers,
Eric

Thanks Eric.

I did find a part number for the cradle bushings off a Reatta. They're probably not the same durometer, but they're better than nothing. Assuming GM hasn't discontinued those, I'll at least have original-type bushings to start off with.

I still haven't given up on the aluminum ones - from what the SHO guys say, its probably one of the cheapest bangs for the buck as far as suspension modifications go (I figured around $150 in materials, plus labor for me to make them), but if I'm going to go ahead and do it, it would be best to have something close to stock to do a fair comparison against. Hopefully I'll have the close-to-stock setup soon.

Interestingly, all six holes in the cradle are set up for either of two types of bushing. The Allante uses four large ones, and two smaller ones. The Reatta apparently uses the smaller on all six points. I imagine with two types of bushing, and various types of rubber, GM has quite a bit of leeway in tuning for various models. Pretty interesting engineering.

Too bad they didn't make a better effort to ward off corrosion...

[speedyguy]

You can get solid mounts for caddies all the way up to the CTS. You eat your teeth but some of us like that.

Ty

[eehoepp]

Originally Posted by ckucia

Too bad they didn't make a better effort to ward off corrosion...

Ummm, yeah. The corrosion thing is why I have a dozen hockey pucks holding the cab of the S10 to the frame. FWIW, at $1 per hockey puck, they are quite literally the best bang for the buck. They also drill out amazing well for the center bolt, considering they are rubber.

One other thing I noticed when I had the engine cradle mounts out was that the rubber on each one was embossed with the name of a color (e.g. ORANGE, BLUE, RED) in raised letters. I assume that these are different durometers or simply designate how beefy or dainty the chunk of rubber is.

I would seriously look into the urethane pickup cab mounts. This same style mount is used on full size GM pickups, too. Aluminum blocks will do the job, but they will result in a lot of harshness in the ride. Uretahne parts are a lot firmer than the stock rubber, but they let you keep the fillings in your teeth. I have rebuilt the front suspension on a couple of my vehicles with urethane parts & I like the way they ride and handle. Tight, but not harsh. And I think you'll be able to get six urethane mounts for less than $150, too.

Good luck & post your results.