Trying to restore "New Car" ride to Jeep GC


#1

I have a 2004 Jeep Grand Cherokee with just over 50k miles. I recently replaced the tires (Bridgestone non-agressive LT tires) and shocks (Gabriel non-air) original equipment grade shocks.



While the handling and cornering are greatly improved…no body sway when exiting the highway, and greatly improved handling when changing lanes on the highway…I feel every little bump in the road and the ride actually seems ‘hard’.



What else needs to be replaced to get the “new car” ride back, or what did I do wrong?



Tom


#2

It never had a “new car” ride. It’s a truck and it rides like one. You want a decent ride, get a Crown Vic.


#3

If you had passenger type tires and replaced them with LT tires the ride might be a little stiffer. Check your tire pressure, when I had LT tires put on my Blazer (replaced the OEM tires), the tire pressures ranged from 35 to 44 PSI when I picked it up from the shop. I lowered the pressure to 32 Psi (recommended on the door sticker) and the ride was much better. I keep the pressure between 32 (comfort) and 35 (better handling).

Ed B.


#4

I’ve owned the Jeep since it was new, and it had a “New Car” ride…for a Jeep. I am not a novice and know when the handling of a vehicle has deteriorated.

The vehicle rode much smoother when it was new, and the ride (as all vehicle suspensions tend to do) deteriorated with time.

I have owned about 30 cars in 35 years of driving. They’ve ranged from VW Bugs, to BMW’s, to Dodge Pickup trucks, , minivans…and oh yes, a Crown Vic. I would not expect the ride of a CV from a Jeep Grand Cherokee, but want to restore the ride that the Jeep had when it was new.


#5

Hi Ed,

I assume the tire classification is the same or even smoother than what I replaced (Goodyear Wranglers were original). The Goodyears had very aggressive tread design. The Bridgestones I replaced them with are a smoother, less agressive tread. Dealer told me they were same category of tire.

 I will double check the tire pressure.  Thjat may be a good place to start.  I think I remember checking that the tire label called for the same pressure as the door plate of the vehicle, but I will double check.

Thanks


#6

the pressure on the tire wall is maximum pressure for the tire. Usually it’s about 10psi higher than your car needs. Truck tires usually run 30psi or low 30’s


#7

I assume the tire classification is the same or even smoother than what I replaced

Assume, that may be where the problem lies. Perhaps if you listed the before and after tire make/model, someone will look that up on tire rack so you won;t have to assume anything. Tire hardness varies even among the same class of tire. Depends on whether they are designed toward ride or longevity.

[/quote]Dealer told me they were same category of tire. [/quote]

See above.


#8

Interesting…I didn’t know that about the sidewall marking. As for before and after tires: I went to a reputable tire specialty shop where I’ve had mechanical work done before. They looked up the vehicle and the recommended tires for it and came up with the Bridgestones I had installed.

Thanks.


#9

Hi,

Here is a website that has tire pressures by vehicle

http://www.drivegreen.com/PressureValue/Jeep.shtml

Note, this site recommends 35 psi for my Blazer, but the door sticker recommends 32 psi. As per my previous post I set the tire pressure between these two values. The max pressure listed on the sidewall for the OEM tires (Uniroyal Tigerpaw AWR) was 35 psi. The max pressure for the new tires (Uniroyal Crosscountry) is 44 psi. I’ve set the pressure as high as 41 psi, but there was no benefit to it and the ride was brutal.

If you are going to check the tire pressure, treat yourself to a dial gage like this:

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=GHM&MfrPartNumber=S60X&CategoryCode=3192

I’ve been using one similar to this for 20 years, the pencil guages are not as accurate.

Ed B.


#10

HI and thanks again, Edb


#11

I suspect it has more to do with shocks than the tires. I don’t know what “gabriel OE grade shocks” are, but I assume they are not really OEM. When I bought my current car, someone had installed some cheap asian after-market shocks (KYB or something similar) and it didn’t handle correctly until I replaced them with four OEM shocks. I would probably try swapping out the shock to she if it changes things. If that doesn’t help. you can always try a different type of tires.


#12

Hi,

I went to the Jeep dealer to purchase replacement shocks, and they were (as expected from a dealer) ridiculously expensive. The original equipment shocks that come on most SUV’s, are generally car-ride shocks, sized to fit the vehicle.

The vehicle always had a nice, car-like ride. I went to a local parts store, asked for replacement shocks, and he came up with 4 options. Heavy duty off road models with coil springs and rubber boots, special handling models, super cheap “economy” models, and what the computer listing described as OE (Original equipment) replacement shocks.

I installed the OE model, expecting them to behave the same as the originally installed shocks, and the rest is history as described above. I guess I’ll just have to live with a somewhat harder ride, or go back to the Jeep dealer and buy a set of TRUE original equipment shocks for the car. Maybe that will get the ride back to what it should be.


#13

look, it’s a tradeoff. You say the handling’s a lot better. Better handling = worse ride. That’s why race cars don’t exactly ride like a limo. You have to choose whether you want to sacrifice some of the cushy ride for better handling.


#14

I guess it depends how time/money you want to put into restoring your ride. Maybe a jeep forum can tell you which specific shocks are OEM so you can shop around. Maybe different tires will make a difference too, it’s hard to tell what’s going on when you change more than one thing at a time.


#15

Before you go to all that trouble, drop the air pressure in the tires to 26-28 and drive around block and see what that feels like…You might not want to keep it there, but you will at least know what the problem is…