Write-Up: Subframe/Cradle Mount Insulators & Bushings

I can't tell from Codiths pic where the engine hoist supports the motor, but in your picture Aaron, its clear that you aren't using the engine lift brackets that are mounted on the block itself, how come?

Engine mount brackets? You mean those ugly metal things that add weight and get in your way when you try to work on the engine?

I don't have the bracket mod!

Ya I know, mine are still there, trying to keep it lookin' showroom.

But wouldn't you rather re-mount the brackets rather than tryin' something else?

AA wrote:

Engine mount brackets? You mean those ugly metal things that add weight and get in your way when you try to work on the engine?

I don't have the bracket mod!

Thats riviera modding 101. Did that when i gutted the air box. Havent looked back since

I don't have the lift brackets either but it might have been simpler if I did. I don't know because I think the factory engine lift brackets are meant to evenly lift the motor up, not so much the transmission attached to it. I found I needed to do some shifting around with the hoist to do the motor mounts and stuff.
I used an engine leveler and connected it to the drivers side heads on the drivers side of the motor and on the passenger side, I think I ended up connecting to the alternator mount bracket? I know I had try a few lift points to get it about even for lifting the front and back up together.

Super easy with the ratchet straps. It was like having a lift on each side of the engine. I could have done it underneath a tree!

Can anyone else verify if the rear upper bushings spin freely once they have been replaced and torqued down?

with my car on the ground i can reach down there and rotate the rubber bushing with my hand. Are mine just so compressed and reamed out that they are not even doing their job?
All the bolts are tight btw. From what i can see the rubber looks good too.

Notice the inner rear upper bushing is completely gone!
Here is a pic of what i got today from the dealer to as replacement, they seem odd and i can see why the old ones just deteriorated.

The upper insulator rings should not spin freely. Are your cradle bolts torqued tightly?

As tight as i can get them with a 2ft breaker bar

And you replaced the lower insulator? Something's not right here. Did you reuse the original bolt?

I have not replaced anything yet. In the pic above the left upper has no bushing. I just ordered them from the dealer. Everything else apears to be in good shape and the hardware is all original.

Oh, I see. The top insulator ring looks to be loose because the bottom insulator is gone or in bad shape. Once you replace the bottom piece, the cradle should properly compress the top one.

I replaced all the cradle bushing parts last fall. I just went out and checked and my rubber spacer bushing spin freely also, and I have them torque down really good also. They probably compress as the cradle compresses (when the weight of the cradle moves left to right as you take turns). Seems normal to me.

https://2img.net/r/ihimg/photo/my-images/90/img20110512112233.jpg/


The ones you got from the dealer are definitely the inners....my outers where black and my inners where that tan color.

Mark, did you notice a difference when you replaced the bushings or did you do other suspension work at the same time?
I dont know much about properties of material engineering, but these orange/tan bushings dont seem strong enough to hold up my weight, let alone keep the cradle from jolting around.

Just replaced the cradle bushings, no other work done at that time. I did notice a difference, since my passenger side outer cradle bushing spot was completely rusted out. Every time I took a left turn (moving weight to the right side of the car) I heard a "pop". When I lifted the car to look, most of the bushings were rotted away. I even had to fab and weld a disc to the outer cradle bushing spot so the bushing wouldn't pull through the bottom of the rusted cradle.

The spacers you are talking about are not actually holding anything. If you look at the way the cradle is designed, it sandwiches these spacers between the cradle and the frame.....and the fact that they are spinning freely leads me to believe that these don't actually hold any weight, they just act as true spacers between the frame and cradle (almost like a bump stop, plus the outer spacers are much strong than the inner). The bolts and bushing below the cradle are whats holding the weight. I hope that isnt confusing.....

I just checked mine. The uppers are compressed (they bulge out slightly), and can't be turned by hand. I tightened the bolts to 120 lb-ft with a torque wrench (estimated, I'm not sure the spec). Be careful tightening with that breaker bar - don't want to strip out the treads!

I double checked mine, they are also about 120 lb-ft.....the drivers side spins freely and is not bulging. The passenger side is about to spin freely, but doesn't (on the verge) but is not bulging either. I would think those bolts bottom out eventually, no?

Are you using the stock bolts? Are the bolt part #'s the same for a 98 as a 96?

The uppers on the front part of the cradle (2 at the front of the car) are seem compressed, but not the rears (4). I really don't think these hold anything, since you are sandwiching them in between. I really don't know, if you find out Id love to know.

Yes, the bolts are the same part # for both years. I reused the stock bolts on front and back positions, only substituted new one on the middles. I don't think the upper insulators are supposed to be compressed a lot, but I also don't like the idea of them being loose. Think about it - when you hit a bump, that would mean the engine would actually travel upwards a distance before contacting and then compressing the upper insulator.

AA wrote:

I don't think the upper insulators are supposed to be compressed a lot, but I also don't like the idea of them being loose.

Yes, this is what I think too. They are just upper insulators/spacers (the bushings at the bottom take all the weight).

There is prob like a snot hair of space between the spacers and the cradle on mine. Even thought it spins freely, its still rubbing on both the top and bottom of the spacer. I don't even think you could fit a piece of paper in there.....but it will spin if I try. It wont move up and down....

7901mark wrote:

There is prob like a snot hair of space between the spacers and the cradle on mine. Even thought it spins freely, its still rubbing on both the top and bottom of the spacer. I don't even think you could fit a piece of paper in there.....but it will spin if I try. It wont move up and down....

same here.

Also you cant see on the picture but the bottom bushing looks about as good as the top one.

So Matthew, you are only changing the rear upper bushing at the moment correct? Did you have to support the motor for a partial swap?

BMD wrote:

So Matthew, you are only changing the rear upper bushing at the moment correct? Did you have to support the motor for a partial swap?

yes i am only replacing the upper inner bushing. I will probably do it Sunday afternoon and i will post my results. I am really hoping i can just lower the rear corners a little and slide in the bushing.

you should be able too...pretty much what I did. Loosen the outers (bolt out of the inner) and side it in. Do you have access to a lift, or are you jacking the car up?

I also heard that when you mess around with the cradle, you might want to check the alignment at some point.

no lift access. I will have ramps, stands and 2 jacks at my disposal.

7901mark wrote:

you should be able too...pretty much what I did. Loosen the outers (bolt out of the inner) and side it in.

I am probably wrong on this, but does that mean that if you do symmetrical bushing replacements in pairs that you don't necessarily need to support the motor and trans?