Write-Up: Subframe/Cradle Mount Insulators & Bushings

ewolfe0050 wrote:

Abaddon- there are 6 mounts but each mount is made up of the upper and lower so 12 bushings total.

Well played.....

Thanks guys! Going to stop today to get the part number. I will post it in case anyone else needs it!

My dealer finally gathered up all the pieces I requested. It took a bit for some of it since most of the pieces are technically discontinued.

Here's are some pictures of the main pieces basically stacked as they are on the car.



In this last picture, my fingers are basically where the subframe would be in relation to the retainers & insulators. The larger retainers go to the top.
In the bags are the nut plates that go all the way at the top and the plastic shanks that appear to fit into the top retainer. The only thing that I don't have here are the bolts. I didn't buy them because they are in perfect condition and appear to be practically resistant to corrosion.

As I said earlier, my car is actually missing the lower retainers and lower insulators on two of my rear mounts, I'm guessing due to the lower retainers rusting out and letting go. I have no desire to ever do this again so I just got everything - all stock pieces.

I suppose this could get it's own thread but I believe it can be very useful here for anyone that may be working on this.

I have for sale 4 (6 on the car) of the lower retainers new from the dealer. (I had to buy 10 - they come in packages of 5 WTF?)
BTW, these are the pieces that I lost two of on my car from age and essentially the reason I got everything else in the first place so they are a pretty good thing to have your hands on. I also have the little plastic shanks for the top for the same reason (had to buy 10)


I'll sell them for what I paid at the dealer with my discount.
$1.67ea for lower retainers
$1.67ea for plastic shanks
Basically $20paypal, I'll put the 8pieces in a flat rate box.

Man if I wasn't broke I'd be all over them. I just pulled this from mine tonight.

Gm dealer will have these, I replaced all 4 last weekend. Took about 4 hours. One bushing had completely rusted through the cradle. I had to fab some sheet metal and weld it up to hold the bushing.

I paid about $250 for parts to replace all 4 bushings.

Thanks Mark, do you have part numbers?

AA wrote:

Thanks Mark, do you have part numbers?

Sry guys, I threw my receipt away. I think it was abt $250ish for 4 bushings, 4 bolts, 8 spacers....If you call GM parts dept, they will certainly give you the part numbers. Ill keep looking

AA wrote:

Thanks Mark, do you have part numbers?

they used to be posted on another thread, maybe AA can point to it for us I can't find it...

Albertj

The cradle mount situation is getting worse. The two (out of 4) in the back have long since let go and it looks like the other on the rear passenger side is loose as hell. That would explain my noises.

I gotta get on this!

Poping when turning? I had similar issues. One of the mounts was completely rusted out. I had to fab some sheet metal discs so the bushing had something to rest on.

The cradle will flex down, so make sure when you lift the car you also brace the cradle before replacing the bushings. To replace the top bushings you'll need to separate the cradle to fit them in. Hopefully they'll come off easier than mine did. All rusted up and shot. Even after replacing all 4 rear bushings, I still have some poping which might be failing due to more rust, which Im sure Ill eventually have to repair with more sheet metal . Very frustrating....

Well I put in the order from Morad for a fully dressed cradle from a 2000 Bonneville SSEI. It has the control arms and stuff on it still. I'm hoping the rear trans mount is either the same or swappable with mine. The front trans mount that the bonne uses is the straight up and down hockey puck style mount so I'm either going to switch to that since I already have the bracket for it or use the riv one if they have the front-to-back through hole for it on the frame. It actually looks like it does in the pics but I can't be sure until I look at it close.

The mounts on the passenger and driver side of the car are connected to the body, not the frame, so I'm not doing anything to those. I actually ordered a new riv rear mount on one of the GM parts sites new for fifty-something. If they actually have it, that'll be nice. Either way mine right now is completely shot. The sleeve that the bolt goes through is sitting all the way at the bottom. Whether I get that new one or used replacement, I'm going to fill it in with shore 85A hardness poly. That would stiffen it up a little and give the rubber additional support so at minimum it should last a while.

I wish I had more time to do research and figure things out more so as to reduce risk of this not working out but my front and rear mounts are in straight piss ass shape and I have 3 out of 6 cradle mounts functioning. It's not so much an issue of if but rather when I'm going to be driving along one day and the back of my cradle comes down.

turtleman wrote:

Well I put in the order from Morad for a fully dressed cradle from a 2000 Bonneville SSEI. It has the control arms and stuff on it still. I'm hoping the rear trans mount is either the same or swappable with mine. The front trans mount that the bonne uses is the straight up and down hockey puck style mount so I'm either going to switch to that since I already have the bracket for it or use the riv one if they have the front-to-back through hole for it on the frame. It actually looks like it does in the pics but I can't be sure until I look at it close.

The mounts on the passenger and driver side of the car are connected to the body, not the frame, so I'm not doing anything to those. I actually ordered a new riv rear mount on one of the GM parts sites new for fifty-something. If they actually have it, that'll be nice. Either way mine right now is completely shot. The sleeve that the bolt goes through is sitting all the way at the bottom. Whether I get that new one or used replacement, I'm going to fill it in with shore 85A hardness poly. That would stiffen it up a little and give the rubber additional support so at minimum it should last a while.

I wish I had more time to do research and figure things out more so as to reduce risk of this not working out but my front and rear mounts are in straight piss ass shape and I have 3 out of 6 cradle mounts functioning. It's not so much an issue of if but rather when I'm going to be driving along one day and the back of my cradle comes down.

Turtle,
When you do this job will you take some measurements for me. I'm specifically interested in the dimensions of the hole spacing for the Steering Rack. I need to know the distance the bolt holes are apart from each other so I can try and determine if a Non-Magna-steer Rack will bolt to the Riv. Does the rack bolt to the cradle.? If so, you will be finding out if your using a Bonneville cradle and the Riv steering rack.
I've been wanting to change this over for the past couple of years but can't seem to get any of the Rack re-builders that I have contacted to tell me the mounting dimensions for either the Riv and a Bonny.
The Bonny came with or without Magna-steer as an option so it would be a good candidate to use for a swap.
I know someone local that has a SSEI that came with Magna-steer and he was able to install a non-Magna-steer as they list P/N's for both to fit that car. He finished the job and returned or got rid of the old rack before I had a chance to do any measuring. I can't go to the junk yards and crawl under cars to take measurements because of my back problems. As it is I will have to pay someone to swap the rack for me, if I can find one that fits.
The dude with the Bonny was irritated by the same highway vibrations that I and others, experience with the Riv's and he was able to eliminate it by eliminating the sensitivity by changing to non-magna-steer. All I have to do is find out if a certain year bonny or whatever will fit the Riv and I'll replace the pump as well and get rid of the over sensitive magna-steer.
Regardless of the vibration issue, I do not like the magna-steer and it's limited effect on the highway. I want a firmer steering input and feedback.
Thanks for any info you can provide.
Also, what was that front sway bar out of that I bought from you. I forget. Having that installed tomorrow hopefully along with some other work I cannot do.

If the cradle you get from the 00 Bonny has a steering Rack on it and it is non-electronic and you are not going to use it, let me know. I'll try it if it has any life left in it.

Rick

Rick, this cradle comes with the sway bar and control arms - no rack unfortunately. I'm interested in getting a non-magnasteer rack myself but right now I just need to fix what's broken. Once I have the cradle, I'll get everything everyone needs - no worries.

turtleman wrote:

The cradle mount situation is getting worse. The two (out of 4) in the back have long since let go and it looks like the other on the rear passenger side is loose as hell. That would explain my noises.

I gotta get on this!

The first post on this issue from you was in Jun of 2008. Is this the same problem that you just let slide or this a recurring problem.????

If this is the same problem from 2008 then I don't need to be too concerned, although I do want to replace them VERY soon.

I need to know because Derek found my rear 2 washers rotted off today and the rest aren't that pretty either. Do you have any spares or should I just order from the dealer.?
Do you have any P/N's of the washers, they are all the same P/N aren't they.?

Thanks for any info you can provide.

I went to one of the yards today for some other stuff for my friend's t-bird mainly and found a '99 aurora that pretty much had all the front bumper and fender liners off so I stopped and took a close look around the cradle mounts for access ways to the nuts. I don't really see anything other than what I already knew about. Here's some cell phone pics.


passenger side rear two mounts
If you look right where the bent-to-shit inner tie rod is, you can see the access hole in the frame for the one cradle mount nut. That is on the driver and passenger sides.

Here's a few shots of the front cradle mount and surroundings






Let's just hope those other 4 top nuts hold themselves together...


bonus pic from the yard...

I've tried getting them off, a number of times,they always brake.Maybe a hand held torch,heat them up then they will break free?

the best thing to do with those bell shaped washers is to weld them to the cradle and hard mount the cradle to the frame. i just thought of that,and like an ass i threw them out along time ago before i had a welder. i bet you wouldn't experience a whole lot of difference anyway,the motor mounts are way soft and soak up alot of the jarring

robotennis61 wrote:

the best thing to do with those bell shaped washers is to weld them to the cradle and hard mount the cradle to the frame. i just thought of that,and like an ass i threw them out along time ago before i had a welder. i bet you wouldn't experience a whole lot of difference anyway,the motor mounts are way soft and soak up a lot of the jarring

So what are you trying to say. Is it best to replace what i have with good OEM parts or do i need to have something made for a stock Riviera that isn't driven hard.
Or do I need to have something custom made that is driven hard.? i'm trying to figure all this out as well.
please provide some feedback on this subject, not smoke and mirror's.
Rick

well...if you want to replace all the cradle bushings(isolators) then its a good idea. but if your looking to get a little more handling performance out of the riv,then it would be best to take the bell shaped cupped washers in turtles photo and weld them to the cradle,cut down the bolts and hard mount the cradle to the frame. and just do away with the rubber isolators in between.
when the car corners hard,and along with the very soft control arm bushings,the entire cradle is allowd,by the isolators,to move around. to prove this,all you need to do is take a square piece of wood and at each corner place a small cylinder of rubber,doesnt matter what size,but big enough to visually analyze the movement the square of wood is subjected to. attach the rubber cylinders to the block and then attach the model to a table or something. now take the block in your hand and move it around. it moves for and aft and side to side.the control arms attached to the cradle are along for the ride too! this is movement that causes vague and downright scary handling at higher speeds. it was engineered into the system to isolate the driver from road shock. if you like to DRIVE then this is isolation that you can do without.
IMO.if one is satisfied with the stock riv ride and doesnt push the car to do things that it would need upgrading to do,then the riv is just fine. ive considered that hard mounting the front cradle to the chassis would transmit alot of vibration to the car and that the motor mounts can fail prematurlly. oh well. a mount here a mount there,as long as you have the ability to fabricate your own mounts then premature weare of the mounts should not be a worry. the surrounding components,rack,engine,suspension,should not get anymore stressed than they allready are. the next step in the plan is to replace the stock rubber bushings with poly or nylon. back and front. believe me. the riv will open your eyes to another world of handling and corner grip. dont forget to get a stiffer than front swaybar. (im working on it). hope that clears it up for anybody interested.

Thanks for your input Robo, I have already replaced the front and rear sway bars with something much more substantial.
Now due to the missing(due to corrosion) front mount washers, i am very interested in doing more of a permanent mount for the front cradle.

I'll deal with the rear cradle later.

Thanks for your input.,
Rick

thanks. and another newtons advantage to the oh so soft cradle mount isolators is, when taking a corner hard,the engine is allowed to move ahead of the car oh so slightly causing a stunted slingshot effect.very unsettling and the suspension agrees too.

here is a pic of hard body mounts that might work with the riv. good luck trying to get diameters and measurements from global west or jegs!





anybody who has removed the stock cradle mounts/isolators, recognizes the similarity.

robotennis61 wrote:

here is a pic of hard body mounts that might work with the riv. good luck trying to get diameters and measurements from global west or jegs!





anybody who has removed the stock cradle mounts/isolators, recognizes the similarity.

What does Jegs sell these for.? You know better than buying something that is not made for our cars, otherwise you would have already bought the set and be doing a drive cycle with them.

I don't have the details but Ewolfe mentioned something very doable that was along the lines of either switching to GP hardware or GP insulators for increased firmness. I know I'm keeping that stuff stock myself but it sounds like a pretty reachable option if you're going to buy the parts anyway. Maybe he'll chime in with the details.