Write-Up: Installing Rancho F-250 shocks on the Riviera

i have to point out,but, if the rssa is not isolated and bolted down ,it is still able to move up and down.the rssa is under constant pressure while the oem air ride system is functional. when you eliminate the air ride the rssa is not under pressure.
im doing my best to have my fabrication shop find the time to modify the rssa but they are swamped. i might have to look elsewhere to have this done as i too am sick of the clanging noise.

Robo, I thought you eliminated all the movement from the RSSA by installing hockey pucks to replace the ever flexible OEM rubber mounts.
Or am I mistaken.?

kinda, rick. it didnt take too long to discover that the rssa needed further work. the hockey pucks went right into place perfectly but didnt do the job. they work great on the front though.
my local fabrication shop will weld plates to the rssa and through bolts to attach it to the body. soon i hope......

AA-

Quote :

Eric, sorry to hear. So where will you go from here?

I just found a EnergySuspension dealer here in town that can order replacement bushings so it looks like I will be fine.

Is this the bushing in the bottom eye of the shock?

Keep us updated!

I had the same issue with some Rancho adjustable shocks in my Grand Cherokee. The bushings disintegrated in about a week.

Rancho said they had gotten a bad run of bushings and sent me replacements. I installed the new ones but they only lasted 2 weeks.

My solution was to cut apart the origional shocks (which had 140,000 miles on them) and press those old rubber bushings into the Ranchos. They have been great that way for over a year and 11,000 miles.

They're really a crap company. There's Bilstein, and then there's everything else. (Ohlins and Penske are great too,...although Ohlins always valves their shocks backwards and Penske stuff is like $5000 - $10,000 a set.).

I'd love to find a Bilstein or even just some mediocre Konis that would fit on the Riv.

This rear air ride (AKA "wallowy, clunk ride") is driving me nuts. Sensor good and adjusted,.. I put on new Monroe shocks,...replaced the compressor,...new plastic lines,...leak tested everything,....and still the compressor runs often. And sometimes it won't run while driving and I'll get a loud clunk over every bump because the top of the air cylinder isn't all the way to the top.

To my eyes,..air ride is a technology still waiting to happen. It's a mess in every Cadillac I've ever seen. None of the European companies use it. BMW and others use hydraulics for that. Smooth, silent, strong and reliale.

duckstu wrote:

This rear air ride (AKA wallowy, clunk ride) is driving me nuts. Sensor good and adjusted,..new shocks,...replaced the compressor,...new plastic lines,...leak tested,....and still the compressor runs often. And sometimes it won;t run while driving and I'll get a loud clunk over every bump because the top of the air cylinder isn;t pressed firmy againstthe chassis side.

Air ride is a technology still waiting to happen. It's been a disaster for Cadilac and for Buick too. Failure city.

They've been using it for about 30 years, basically unchanged, and mostly trouble free. I know of '85 Rivs that still have the air ride working fine. You must have a leak somewhere. Something is up with your setup.

Try spraying all around the fittings etc with soapy water and see if you can get it to bubble. Find your leak!

deekster_caddy wrote:

They've been using it for about 30 years, basically unchanged, and mostly trouble free. I know of '85 Rivs that still have the air ride working fine. You must have a leak somewhere. Something is up with your setup.

Try spraying all around the fittings etc with soapy water and see if you can get it to bubble. Find your leak!

I did that. Soapy spray and sometimes straight dish soap.

I've seen 20+ cars with the system and have owned 4 or so. My parents Lincon Continental is the ONLY one that has worked properly.

Most of the cars that I have owned had had the system replaced with a simple tire valve, and you had to fill them manually.

Agree, my air shocks have been replaced with Monroe MaxAir and work fine, no clunking, and not much wallowing, either. KYBs up front fixed that, and they're still very good after more than 120k miles.

I have replaced the pump with an air valve, no leaks over months of use.

Has anyone tried any other shocks?

I'd bet dollars to doughnuts the front shocks on my 1998 Grand Cherokee would be a good fit. Bar-pin bottom mount and stud top mount.

All we need to find is one that has stud top and bar-pin bottom and has roughly the correct extended and compressed length,.....and that is for a vehicle with roughly the same axle weight.

Probably 1,700 lbs on the rear axle,...so you'd look for a vehicle with 1,700 (on whatever axle the shock was from) if you wanted a normal ride,...or a vehicle with 2,000 lbs on that axle if you wanted a firmer ride.

Really though,...shocks should be matched to the spring rate,...not vehicle weight. That's another reason the air helper systems never quite work well. The air system does change the spring rate,...yet the dampening doesn't get changed. But that's a minor issue on a non-performance car.


Has anyone got a set of shocks out of the car that they could measure for us?

Stud diameter,....compressed length (as measured from where the stud meets the shaft, to the center of the bar-pin),....and extended length measured the same way?


I can buy a couple various shocks and have them run on a shock dyno to see how their rates compare. A friend of mine develops suspensions for Porsche, Peugeot, Renault and the domestics. He's got access to a killer shock dyno,...chassis shaker rig etc.


That might be something fun to do. Put the Rivi on the chassis shaker and see how many light years my current Monroe / Gabriel setup is from ideal.

hey duckstu,if your friend is a suspension specialist,work with him to develop a strut "housing" for a bilstein cartridge...get on it man!!

robotennis61 wrote:

hey duckstu,if your friend is a suspension specialist,work with him to develop a strut "housing" for a bilstein cartridge...get on it man!!

Do you have a model number for the Bilstein cartridge you want to use?

Usually BMW and other strut housings will fit a Bilstein cartridge.

Bilsteins have the best readily available dampening on the market,...although they have a lot of seal stiction, and with their high gas pressure and large diameter piston,...they have enough extention force to lift most cars up 1/4 - 1/2" in ride height on the axles with struts (so on BMWs' or our Rivs',... just the front gets raised).

All we need is the threaded tubes and top nuts,...then we can cut the bottom part that attaches to the knuckle off ours and weld them onto the tubes. That also gives you the freedom to move the bracket up and down the tube before welding to compensate for different ride heights or to compensate for a Bilstein cartridge that isn't the same length as the stokers.

My friend has a Bilstein master catalog (and works directly with them). I'll ask him if he has data on the GM platform and can find a Bilstein that matches up.

absolutely duckstu! at the limit a oem or a kyb housing can be sacrificed to make room for the cartridge. i suspect that even pinch bolts welded onto the housing will compress enough around the housing to hold everything in place .....this could be huge duckstu? just imagine a riv that handles like a m5?.........think about it!
dont have a model for the bilstein cartridge,but if your buddy has a master catalogue hell have acces to ,dias,and extended and compresed heights...awsome!

robotennis61 wrote:

absolutely duckstu! at the limit a oem or a kyb housing can be sacrificed to make room for the cartridge. i suspect that even pinch bolts welded onto the housing will compress enough around the housing to hold everything in place .....this could be huge duckstu? just imagine a riv that handles like a m5?.........think about it!
dont have a model for the bilstein cartridge,but if your buddy has a master catalogue hell have acces to ,dias,and extended and compresed heights...awsome!

He, he, he. Well,..M5 might be a bit of a stretch. The Riv is very long,..has the rack & pinion behind the axle instead of in front like all high performance cars (bad for bump steer), it's front wheel drive, vague steering feel, etc, etc,...but I know what you're getting at.

Better suspension bushings,...Bilstein struts and shocks, Eibach Pro Kit springs, 18 x 8" rims with 245 rubber and some bigger anti-sway bars and the Riv would drive even better than it looks.

What my friend would need is the inner diameter of our strut housings, and the extended and compressed lengths of our stock struts.

I threw mine out without measuring them. If it were warmer I would just grab one off one of the cars at the parts yard.

Actually,....it's just two 22mm nuts and three 15mm nuts (and the two 10mm ones for the sensor and brake line). The struts come out of theese cars in about 2 minutes flat (presuming the car is already in the air and wheels removed,....which they are at the junk yard). Perhaps I'll just go and grab a couple tomorrow and cut them up.

I'll have my friend with me. We're having pankakes, then going to a local dyno-day and probably tuning the Riv. A swing past the parts yard would be fun.

Robo, could stop using abbreviations and acronyms that nobody knows what they mean.
Please spell this stuff out.
And try to form sentences that are understandable or use some punctuation.
Don't mean to be a Dick, but I'm having a very hard time understanding what your saying. It's getting worse by the week.
Maybe it's my Alzheimer's, but IDTS.

ORIGIONAL EQUIPMENT MANUFACTURE-DIAMETER-RIVIERA - sounds awesome duckstu! i think this is the beginning of a beautiful friendship!

Monroe shock catalog gives these dimensions. may not be useful by themselves, but if you measure one year you could use to find diffrences for other years.

comp ext. travel upper mount lower mount
1995-99 rear 14.5" | 24.375" | 9.875"| M10 threaded| cross pin,
closed 5/16"holes,
2 7/8" on center foot not for comp and ext says" bumper stop unit, dimensions shown at bump stop".
length is from center of bottom bushing to between bushing on threaded rod at top, diagram assumes bushing are 5/8" thick.

comp ext length travel
1995-96 11.5"| 18.5"| 14.5"| 7"
1997 11"| 18.5"| 14.25"| 7.5"
1998-99 10.375"| 17.5"| 14.5"| 7.125"
ext. has same footnote as rears comp and ext length are measured from top hole on bottom to wear the shaft is machined down for the strut mount
(picture is not clear if center or top of hole). length is from top to bottom of cartridge

tables were straight in quick reply, forgot to preview. still readable I guess.

Fixed the links in the write up.

Besides the obvious difference in technology. Are there any real advantages to the Ranchos over the Monroes?

The ranchos are adjustable, so you can adjust their performance from soft to firm. Rancho doesn't say whether the adjustment is for bump or rebound, so not sure what you get, or how you would tune things. Probably just experiment with trial and error.

Personally, I like the Maxairs for their adjustable level control. Ride height is another way to tune the rear suspension's behavior. This also lets you "tune" the looks of the car to an extent.

I feel like my monroes have a very harsh rebound to them.

Could a universal shock be fabricated to work on our cars like the ranchos did?

I was thinking these shocks, i don't know if these are the right dimensions, but they make a lot of different versions.

http://www.streetbeatcustoms.com/RideTech-by-Air-Ride/Shocks/RideTech-Black-Series-Shocks-_-20259905/869872/

I know the cross pins would need to be taken from our stock shocks and put into these shocks the same as the ranchos. I don't know how these shocks perform, but i'm just trying to find new ideas for shocks.

here is part of their website that has a higher end shock

http://www.ridetech.com/store/components/shocks-components/

robotennis61 wrote:

just found a complete coil over shock conversion kit at strutmasters.com        interesting!

http://www.strutmasters.com/Buick-Riviera-Air-Suspension-Rear-Conversion-Kit-p/-cad-r5ns-br.htm

For around $125 more, you can get my rear setup and get way better handling.
I'll build you the little mounting brackets. My setup will totally work with a oem front set up.