"Why does my TJ ride so harsh?"
I must see this question come up at least once or twice a week. I'm writing this post and sticking it in the FAQ section in hopes that people who are experiencing this issue will benefit from this information.
So you've just installed a new lift and bigger tires, and now you're wondering why your TJ rides horribly. 99% of the time the ride quality is determined by these three factors:
How can I fix a harsh ride on my Jeep Wrangler TJ?
Tire Load Rating
The ideal tire load rating for a vehicle as light as the TJ (yes, the TJ is light when compared to a full size truck) is a C load rated tire. Most people pay no attention to the load rating on their tire and end up with a E load rated tire, which is meant for a truck (which weighs considerably more than a TJ). On a truck those tires will be fine, but on a TJ, they are way too stiff. This isn't an exaggeration either. I've run both C and E load rated tires, and it's absolutely amazing how much better the C load rated tires run. So, if you're shopping for tires, look for C load rated tires. If you can't find a C load rated tires, a D will suffice, but I would strongly encourage you to stay away from an E load rated tire if you want a comfortable ride.
Tire PSI
The idea tire pressure for our Jeeps is around 24-28 psi. I run mine at 26 psi and have found it is the perfect tire pressure. Most often when having new tires installed, the people at the tire shop will set them around 35 psi or higher. Some people will see that E load rated tires can be set up to 80 psi, and they'll set them at 60 psi. All of this is way too much for a TJ. Even 35 psi is way too much. Set your tire pressure between 24-28 psi and you'll be shocked at how much better it rides. Stop over inflating your tires!
Shocks
Certain shocks ride better than others out of the box, period. A Bilstein 5100 for instance is a firmer riding shock than a Rancho RS5000X. I've personally run a variety of shocks including Fox, Bilstein 5100s, OME Nitrochargers, and Rancho RS5000X. In terms of "off-the-shelf" shocks, the Rancho RS5000X is hands down the best riding of the bunch if you prefer a softer and more comfortable ride (they also perform very well off-road as well). All of the others are going to give you a stiffer and firmer ride, which is okay if you're into that sort of thing. The other option if you really want the best-of-the-best is to buy a tunable shock such as the Fox shocks (which are also over two times more expensive) and have someone who tunes suspension for a living (i.e. @pcoplin) set them up for your vehicle. I currently run Fox Offroad 2.0 smooth body shocks that @pcoplin tuned for me, and they ride better than any shock I've ever had, including the Ranchos.
Shock Travel
Shock up travel is important if you want to get the most out of your shocks. Too much bump stop extension could limit up travel and not allow the shock to have enough distance to properly dampen the event. So don't go thinking you can run your 35's with 2.5" of lift and get a nice ride when you only have 2" of up travel.
Bump Stop
One reason your TJ may be riding rough is that your bump stop is not set correctly and you're hitting the bump stop way before your shock actually bottoms out. For this reason, it is imperative that you cycle the suspension and set the bump stop accordingly after any increase in lift height, tire size, or other suspension changes.
Do long arms vs. short arms affect ride quality?
Don't fall sucker to this myth. At the common lift heights for TJs (2-6") short arms versus long arms is going to have no affect on ride quality whatsoever, nor is bushing material. Don't waste your time on this one at all. If anyone tells you something like, "long arm lifts have better ride quality", that is someone who you should NOT be listening to, as they don't know what they're talking about.
Does spring rate affect ride quality?
Yes, spring rate can indeed affect ride quality. However, all aftermarket TJ lift springs are close enough in spring rate that any perceptible effects on ride quality are so minute that it doesn't matter.
Conclusion
So that covers it. Make sure all of those three things are in check and you'll have a very good ride. If you're new to solid axle vehicles, you should understand however that a solid axle vehicle is never going to have the ride quality of a vehicle with independent suspension, plain and simple. You can get our TJs to ride good, but at the end of the day, they are still solid axle vehicles.
If anyone has anything to add to this thread, please feel free to chime in. I'll be happy to add any good information to the original post.
I must see this question come up at least once or twice a week. I'm writing this post and sticking it in the FAQ section in hopes that people who are experiencing this issue will benefit from this information.
So you've just installed a new lift and bigger tires, and now you're wondering why your TJ rides horribly. 99% of the time the ride quality is determined by these three factors:
How can I fix a harsh ride on my Jeep Wrangler TJ?
Tire Load Rating
The ideal tire load rating for a vehicle as light as the TJ (yes, the TJ is light when compared to a full size truck) is a C load rated tire. Most people pay no attention to the load rating on their tire and end up with a E load rated tire, which is meant for a truck (which weighs considerably more than a TJ). On a truck those tires will be fine, but on a TJ, they are way too stiff. This isn't an exaggeration either. I've run both C and E load rated tires, and it's absolutely amazing how much better the C load rated tires run. So, if you're shopping for tires, look for C load rated tires. If you can't find a C load rated tires, a D will suffice, but I would strongly encourage you to stay away from an E load rated tire if you want a comfortable ride.
Tire PSI
The idea tire pressure for our Jeeps is around 24-28 psi. I run mine at 26 psi and have found it is the perfect tire pressure. Most often when having new tires installed, the people at the tire shop will set them around 35 psi or higher. Some people will see that E load rated tires can be set up to 80 psi, and they'll set them at 60 psi. All of this is way too much for a TJ. Even 35 psi is way too much. Set your tire pressure between 24-28 psi and you'll be shocked at how much better it rides. Stop over inflating your tires!
Shocks
Certain shocks ride better than others out of the box, period. A Bilstein 5100 for instance is a firmer riding shock than a Rancho RS5000X. I've personally run a variety of shocks including Fox, Bilstein 5100s, OME Nitrochargers, and Rancho RS5000X. In terms of "off-the-shelf" shocks, the Rancho RS5000X is hands down the best riding of the bunch if you prefer a softer and more comfortable ride (they also perform very well off-road as well). All of the others are going to give you a stiffer and firmer ride, which is okay if you're into that sort of thing. The other option if you really want the best-of-the-best is to buy a tunable shock such as the Fox shocks (which are also over two times more expensive) and have someone who tunes suspension for a living (i.e. @pcoplin) set them up for your vehicle. I currently run Fox Offroad 2.0 smooth body shocks that @pcoplin tuned for me, and they ride better than any shock I've ever had, including the Ranchos.
Shock Travel
Shock up travel is important if you want to get the most out of your shocks. Too much bump stop extension could limit up travel and not allow the shock to have enough distance to properly dampen the event. So don't go thinking you can run your 35's with 2.5" of lift and get a nice ride when you only have 2" of up travel.
Bump Stop
One reason your TJ may be riding rough is that your bump stop is not set correctly and you're hitting the bump stop way before your shock actually bottoms out. For this reason, it is imperative that you cycle the suspension and set the bump stop accordingly after any increase in lift height, tire size, or other suspension changes.
Do long arms vs. short arms affect ride quality?
Don't fall sucker to this myth. At the common lift heights for TJs (2-6") short arms versus long arms is going to have no affect on ride quality whatsoever, nor is bushing material. Don't waste your time on this one at all. If anyone tells you something like, "long arm lifts have better ride quality", that is someone who you should NOT be listening to, as they don't know what they're talking about.
Does spring rate affect ride quality?
Yes, spring rate can indeed affect ride quality. However, all aftermarket TJ lift springs are close enough in spring rate that any perceptible effects on ride quality are so minute that it doesn't matter.
Conclusion
So that covers it. Make sure all of those three things are in check and you'll have a very good ride. If you're new to solid axle vehicles, you should understand however that a solid axle vehicle is never going to have the ride quality of a vehicle with independent suspension, plain and simple. You can get our TJs to ride good, but at the end of the day, they are still solid axle vehicles.
If anyone has anything to add to this thread, please feel free to chime in. I'll be happy to add any good information to the original post.