Rough Ride (rear)

[ImInPA]

Isn't that going to cost a pretty Penny to build and install? and I guess it would nullify your warranty? Do you have any concerns about that?

It is unlikely that new springs will nullify the warranty. The burden is on Hyundai to prove that a failure of the vehicle in any way was due to the new springs. For example, if the radio stopped working, Hyundai cannot reasonably claim the new springs were the culprit. However, if you changed the springs and the rear subframe fell out, they may be able to make a case.

 

[Asus999]

It is unlikely that new springs will nullify the warranty. The burden is on Hyundai to prove that a failure of the vehicle in any way was due to the new springs. For example, if the radio stopped working, Hyundai cannot reasonably claim the new springs were the culprit. However, if you changed the springs and the rear subframe fell out, they may be able to make a case.

I was more thinking whether the Powertrain Warranty would be affected... no the Comprehensive Warranty

 

[Mark_888]

I was more thinking whether the Powertrain Warranty would be affected... no the Comprehensive Warranty

Powertrain is engine and transmission. Why would the springs affect the warranty on that unless there were some extreme circumstances.

 

[Asus999]

Powertrain is engine and transmission. Why would the springs affect the warranty on that unless there were some extreme circumstances.

I dont Know.. I Meerly asked a simple question if he would be concerned with any Warrany issues is he builds and installs new part... No need for long discussion. Yes or No would suffice for me.. You never really can predict what may happen to a car transaxle etc..which the Dealers could then inconvenience you and your repairs because you have some sort on non manufacture part installed.. Either way.. just curious

 

[Mark_888]

I dont Know.. I Meerly asked a simple question if he would be concerned with any Warrany issues is he builds and installs new part... No need for long discussion. Yes or No would suffice for me.. You never really can predict what may happen to a car transaxle etc..which the Dealers could then inconvenience you and your repairs because you have some sort on non manufacture part installed.. Either way.. just curious

You may be right about what the dealer would try and say to deny the warranty claim, but there are federal laws regulations governing such things (assuming the consumer if willing to file a complaint if the dealer tries to deny a valid claim).

 

[Disaster]

This is a informational post not a post for complaining or to get comment.

This morning the SACHs Shocks were removed from the car. They were tested individually. The shocks are NOT THE PROBLEM. For information purposes ans to prove they were removed the number on the shock is 55311 3M801. The car was then lowered and the stiffness of the rear was tested without shocks by having 1 then 2 then 3 burly guys sit on the rear trunk. The springs alone are so stiff that 1 moved it less than 1/8 inch 2 about 3/8 and 3 no quite a half. They bounced up and down, all are suspension techs at a alignment, shock specialty service center, their comments: whoa this baby is stiff and hard.

Added info: the specification for my 3.8 says the springs are color coded either (skyblue-skyblue) or (Skyblue-Pink) mine have a different color code on one spring and the other is not paint coded at all.

Shocks replaced, Ride unchanged. Next step new springs. That will occur this week. PS bushings inspected OK.

That confirms what I've been reading...especially regarding "porpoising." The Genesis oversprung and underdamped. Softer springs would yield a smoother ride. Stiffer shocks would yield more control.

 

[rdunegan]

My 2009 Genesis 3.8 sedan has a rougher ride than my Subaru Outback. I noticed it the first time I drove over city streets or country roads. Back seat passengers have actually complained about the ride. In retrospect, my test drive was over carefully chosen smooth roads. Big disappointment. Tire inflation is correct. Are there any suspension adjustments or other suggestions that would help this situation?

 

[mikec]

Tire inflation is correct. Are there any suspension adjustments or other suggestions that would help this situation?

No "adjustments" per se. Things that can make a difference:

* Tire pressure. Lower pressure reduces the effective spring rate of the tire sidewalls, making the tires absorb more of the road imperfections before they're passed onto the car's springs.

* Lubricating the joints in the suspension parts, and making sure the factory didn't over-tighten the pivot bolts. Anything that causes binding/friction in the suspension will reduce the suspension's ability to respond to minor road imperfections leading to a worse ride.

* "unsprung weight" which is the weight of tires, rims, brake parts, and whatever suspension parts move with the tires. Actually, the ratio of "sprung" to "unsprung" weight is what's important. A heavy car body on light rims+tires will tend to ride smoother than a lighter weight car or a car with heavier wheels+tires over that same road. Think of it this way: the tire WILL have to move to roll over a bump in the road - that accelerates the tire (and rim) upwards. Once those parts are moving upwards, they'll have energy (momentum). The suspension springs should flex to allow that motion... but some of the energy will go into the car body since there is nothing preventing it from moving up a little too. The lighter the car the more it'll end up moving too. A heavy tire+rim will "pick up" a lot of energy going over a bump compared to a light tire+rim going over the same bump. That energy then moves the body. It's the same as hitting a nail with small or large hammers: if you whack a nail with a light hammer, it's not going to move as far as if you whacked it with a heavy hammer at the same speed. The wheel+tire moving up is the "hammer." So installing lighter tires and/or rims can improve the ride by reducing unsprung weight.

* Compliance of the various rubber parts (typically bushings) in the suspension. Production car suspensions use rubber pieces at the pivot points and where the suspension parts bolt to the car body. These rubber parts allow some "mismatch" - manufacturing tolerance, thermal expansion, etc. Also, when the tire hits a bump or pothole, the whole suspension can "give" back or forth slightly thanks to these rubber parts. The softer the rubber, the more they'll absorb before passing disturbances into the car body. Unfortunately, the softer the rubber the sloppier the car handling too: when you move the steering wheel, if the rubber bushins flex a bit that delays the steering wheel command to the tires. Race cars eliminate most, if not all, rubber parts to remove as much compliance (and thus delays) as possible. Sports cars have firm bushings to minimize the compliance. Old Cadillacs, Buicks, Oldsmobiles, etc. had soft bushings which is one reason they "wallowed" like a boat if you tried to make them turn rapidly. A key bushing is the bushing at the top of the spring area: whatever ties the suspension to the car body. These bushings support the majority of the car's weight and do a lot to absorb/dampen the high frequency jitter of bad roads. Tailoring the rubber in these bushings to be soft in the up/down direction but firm in the fore/aft and left/right directions allows a soft ride (by being soft in the up/down direction) while minimizing the steering lag (by being firm in the left/right/fore/aft directions).

Moving up the cost/complexity curve:
* Variable rate springs. Regular car suspension springs are evenly spaced coils. However, you can get springs that have uneven spacing: this results in a spring that is soft near the "average" position for a nice ride over minor (jittery) bumps yet gets stiffer as the wheel moves more over big bumps. For handling such springs cause a little initial compliance (and thus steering delay) until the vehicle leans over a bit, compressing the spring to the stiffer portion. For the majority of drivers/cars out there, this is a good tradeoff. For all-out sports cars that extra compliance isn't so nice.

* Variable rate dampers (shock absorbers). A vehicle without dampers (i.e. no shocks) will bounce up and down for a long time after hitting any bump: the springs will make the car bounce like a superball. Dampers respond to CHANGES in position (i.e. to rate of motion) so, when the vehicle is bouncing, dampers resist that motion. Dampers can be built that have less resistance at the "average" position so they don't respond much to jittery roads... but, like variable rate springs, they can stiffen at higher wheel travels.

Air bag suspensions (like the Korean market Genesis) can have non-linear spring and damper characteristics. Plus, the air bag pressures can be adjusted depending on how much weight is in the car. With US-style springs and dampers, the suspension is designed for a fully-loaded car. When nobody is riding in the back seats, and the trunk is empty, the US-spec suspension can be too stiff. Many pick-up trucks, with leaf springs, have "load dependent" spring stiffness. Next time you see a late model pickup that's jacked up a bunch, look at the leaf springs. You'll often see the upper-most spring is separated from the rest if the pickup is empty. The "rest" of the spring leaf pieces are designed for this empty weight. If the truck is loaded, those springs compress until they touch the upper "beefy" spring which then stiffens the whole suspension. Similar idea to the variable spaced coil spring.

mike c.

 

[rdunegan]

Mike C ... With a treatise like this, you gotta be an automotive engineer. I retired from automotive engineering several years ago ... heavy trucks.

I agree with everything in your reply. One other possible consideration are the low aspect ratio tires used on the Genesis. More sidewall would allow the tires to absorb more of the bumps before getting to the springs, as you suggest. I have never really liked Dunlops nor big wheels and skinny tires on passenger cars. But that's not very changeable.

Thanks for the input from all respondents. I guess I'll try a bit lower tire pressure.

 

[scottdk]

One other possible consideration are the low aspect ratio tires used on the Genesis. More sidewall would allow the tires to absorb more of the bumps before getting to the springs, as you suggest. I have never really liked Dunlops nor big wheels and skinny tires on passenger cars.

When did a 50 aspect/profile tire become a small amount of rubber between the wheel and road? My point being, there is plenty of tire, sure not compared to cars from the 70's, but the Genesis with 50 series is quite normal. My Sonata with a 17 wheel and 50 aspect tires almost doesn't feel right. Too much rubber, and it would handle a bit better with an 18 wheel and less of a profile tire.

I do understand the concept of more aspect/profile, more comfort, but this isn't my Grandfather's Buick either.

Heck, An A8 get's optional 20" wheels and do not look too big for that size of car. I think a 19" wheel would be more appropriate for the Genesis due to the cars size, but it's an odd tire/wheel size and everything costs more. Also loose a little bit of comfort, if even noticed.

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[RedneckEngineer]

My 3.8 came from the dealership with 42 psi in the tires. What a rough ride! I reset the pressures to 33 psi and could really tell the difference; however, there still seemed to be too much harshness over highway joints, etc. Taking into account that the car is capable of speeds over 100MPH and I don't drive that fast, I have reduced the pressures to 32 all around and the ride and handling are much better. I'm sure the manufacturer recommends the higher pressure (33 psi) for liability reasons.

 

[doug725]

That the problem can be solved with tire pressure adjustments is wishful thinking and denial. Sure, you'll some minor improvement if you lower the pressure.. .and put 250 pounds of sand in your trunk.... and change to 17's and so on and on. The problem - my friends - ain't ultimately with the tires.

Mike C ... With a treatise like this, you gotta be an automotive engineer. I retired from automotive engineering several years ago ... heavy trucks.

I agree with everything in your reply. One other possible consideration are the low aspect ratio tires used on the Genesis. More sidewall would allow the tires to absorb more of the bumps before getting to the springs, as you suggest. I have never really liked Dunlops nor big wheels and skinny tires on passenger cars. But that's not very changeable.

Thanks for the input from all respondents. I guess I'll try a bit lower tire pressure.

 

[genesis 45]

Doug, we have been right from the begining..............the ride is so bad for some cars that any change is an improvement........some people think the ride is great, i can not believe they are driving a car like mine..........my 2004 accord rides better over the same roads......after a year of all this nonscence with hyundai and speaking with gripper don i am really starting to believe that some cars have springs that are just to tight and hard..thus not allowing the shocks to work the way they are suppose t0....

 

[GripperDon]

ONCE MORE

The Suspension Complaint is simply that: The, 2009 V6 has a problem with mainly the rear suspension being excessively rigid when subjected to a series (more than 1 ) sharp bump. The effect is indicative of a vehicle with excessively high load rate coil springs and a bi-valved shocks that closes the large orifice incorrectly. (in otherwords the combination is not well match for that situation) This is also indicative of reduction of ground contact load in the read producing a jittery or skittish feeling.

Lower pressure to 30PSI, some but, NOT ENOUGH HELP
REDUCE RIMS TO 17INCH, some but, not enough help
Change tires to series 60 softer construction. Some but, not enough help.

The real solution is simply: Replacement of the existing coil springs with lower rate 15+% coils having a initial free length 15+% longer than the current springs selected so that the resting height of the two suspensions (old and new) are the same but the spring rate loading is on a lower loading ramp. Such springs coupled with new shocks that lock to the low flow position do so at higher flow rate or are just changed out with a simple mono shock. This can now be accomplished by the owner by ordering the appropriate components and having them installed.

Also positioning of added weight in the trunk would increase the load on the rear coils increasing the deflection to balance the increased force, ie. (increasing the stroke of the shocks). Lead sheet laid under the carpeting and spare tire in the weight range of 250 pounds would accomplish the job reasonably well and leave trunk space largely unaffected, The sheeting should, at the very least be contact cemented in place and the headlight leveling position should be adjusted, Also it should be noted that the increased load will place more load on the tires and the rest of the suspension as well as other components, possibly effecting the handling of the vehicle, during both normal and emergency situations as well as durability, It should be duly noted that this procedure is not advised by me but outlined only for illustrative purposes and in fact adding any weight in the rear of any type or configuration is warned against.

Anyone performing ANY of these acts obviously does so under their own guidance and self decision and agree that THEY assume ALL liability for ANY problem arising from the installation and or modification.

 

[STREETS]

Rode a skateboard this morning....
Too a quick ride for paper & coffee this morning. With temps in the single digits (which seems common in almost all the US this week- bring on so-called Global Warming!) I experienced the roughest ride I ever had in a motor vehicle. Sure tires, shocks and all have adverse effects to cold- but my vehicle history also include Corvette, F-150, F-250 and John Deere riding mower...lol. It was a little better after 20 minutes of driving- but not much.
We need the European Genesis models electronic dampening shock system-fast or the suspension issue will stimy Genny sales.

 

[09gen46]

i have 09, 4.6L w/full option. this 'bumpy' 'jittery' ' bouncy' = you can call it whatever... ride issue has been well documented. i've tried several options including: lowering the tire pressure. if you go down to 29-30 range, the low pressure sensors will kick in, giving you that annoying warning sign.

supposedly the '10 model fixed the issue, or made it smoother by replacing the spring with lower tension. '09 has too stiff springs.

don't waste your money changing shocks and bunch of other stuff as other folks have tried some of that...

try to negotiate with the dealer if they'd be willing to swap springs at some minimum charge...

 

[flyboy2]

My house in the woods requires a salt tank for the water system. I put 2/3 bags of 40lb. salt bags in the truck and the ride is much better. It also corners better in the twisties and I feel safer driving at fast speeds.

Might be the easiest $20 fix you will ever experience--

 

[kayroe]

I have owned the 2010 4.6 for almost two years. My car rides great, but as of late, I notice that when I drive across a speed bump or rough roads, I hear a noise that sounds as if something is loose. I know that the sound is coming from the front of the car. I removed the front passenger side wheel and while looking at the coil assembly, I noticed that there is a piece of brown plastic glued to the top of the suspension coil spring. I found this to be hanging off of the coil. I reglued it back on. But it did not stop my mystery noise. Has anyone had this problem, and if so how did you fix it?

 

[yoyo711]

I have owned the 2010 4.6 for almost two years. My car rides great, but as of late, I notice that when I drive across a speed bump or rough roads, I hear a noise that sounds as if something is loose. I know that the sound is coming from the front of the car. I removed the front passenger side wheel and while looking at the coil assembly, I noticed that there is a piece of brown plastic glued to the top of the suspension coil spring. I found this to be hanging off of the coil. I reglued it back on. But it did not stop my mystery noise. Has anyone had this problem, and if so how did you fix it?

It happen to me so when to Hyundai Dealer find out sway bar was no good Yesterday exchange the sway bar. but it's same noise coming from driver(front) side and they find out it's Stroke(shock) so i'm going to Tomorrow get the service. i'll find out tomorrow

 

[SURFDADDY60]

The z rated tires are hard and might be the problem. One cannot have a high performance sedan with great handling and not except some downsides. Touring tires might solve the problem if they are allowed by the warranty, but they would limit the top speed and the handling.