Brutally Harsh Ride - Out of Ideas

[BDiddy]

First off, love this forum! This is my first post but I've been reading and lurking since buying a 2000 TJ Sahara a couple years ago. The forum has been an invaluable resource. This issue aside I love the hell out of my TJ. And even with this ride quality I can't dream of driving anything else.

Issue: When I bought the Jeep, every crack, bump, pebble or seam in the street and on the highway could be felt. I've tried to improve this by following forum advice but still have the same experience. I've researched the hell out of tires and shocks both here and on other forums. I'm out of ideas and thinking that maybe load range C tires are the issue, although this forum led me to think they were a good buy. Potholes send a concerning jolt through the cabin which sounds like the thing is about to rattle apart. It rides like it has no shock absorption in the suspension whatsoever. However, I've run through seriously everything except replacing the tires with something else. I live near the Cascades, so my goal is to have a mostly stock daily drivable Jeep that still has good 4x4 capability on forest roads on the weekends and camping trips. Specs below.

As purchased:
Lift: 0" (stock)
Shocks when purchased: KYB Excel
Tires when purchased: Toyo Open Country 265/75/r16, almost bald, think they were load range E

Things I've tried based on my research here:
Lift: 0" (trying to stay close to stock!)
New coils: Old coils caused Jeep to swing/overhang forward on steep hills, especially when braking, replaced with new Moog OEM spec coils, stability restored!
Factory spare was still mounted, Michelin LTX 225/70/r16, so tried going back to the same size
Switched bald Toyos to BFG KO2s 225/70/r16 load range C @ 28psi - HARSH
Changed shocks to Rancho RS5000x - WORSE ride than before
Changed shocks to OEM standard duty from Crown - no improvement, still HARSH

Current state: BFG KO2s 225/70/r16 load range C @ 28psi, Crown OEM standard duty shocks, no lift. Yes I've tried airing them down to 24psi. Maybe makes the tiniest difference, def not enough to warrant driving on a tire that is clearly, visibly under-inflated and takes your foot to the floor to move it.

Are these tires really that stiff? Curious to get everyone's take. Maybe the BFGs and Ranchos are better in a larger size and lifted TJ? I can't imagine this is normal considering how much people gush about KO2s and RS5000x here. But maybe I should try a set of Michelins. Just feel like I've got to be missing something here!

 

[Irun]

First off, love this forum! This is my first post but I've been reading and lurking since buying a 2000 TJ Sahara a couple years ago. The forum has been an invaluable resource. This issue aside I love the hell out of my TJ. And even with this ride quality I can't dream of driving anything else.

Issue: When I bought the Jeep, every crack, bump, pebble or seam in the street and on the highway could be felt. I've tried to improve this by following forum advice but still have the same experience. I've researched the hell out of tires and shocks both here and on other forums. I'm out of ideas and thinking that maybe load range C tires are the issue, although this forum led me to think they were a good buy. Potholes send a concerning jolt through the cabin which sounds like the thing is about to rattle apart. It rides like it has no shock absorption in the suspension whatsoever. However, I've run through seriously everything except replacing the tires with something else. I live near the Cascades, so my goal is to have a mostly stock daily drivable Jeep that still has good 4x4 capability on forest roads on the weekends and camping trips. Specs below.

As purchased:
Lift: 0" (stock)
Shocks when purchased: KYB Excel
Tires when purchased: Toyo Open Country 265/75/r16, almost bald, think they were load range E

Things I've tried based on my research here:
Lift: 0" (trying to stay close to stock!)
New coils: Old coils caused Jeep to swing/overhang forward on steep hills, especially when braking, replaced with new Moog OEM spec coils, stability restored!
Factory spare was still mounted, Michelin LTX 225/70/r16, so tried going back to the same size
Switched bald Toyos to BFG KO2s 225/70/r16 load range C @ 28psi - HARSH
Changed shocks to Rancho RS5000x - WORSE ride than before
Changed shocks to OEM standard duty from Crown - no improvement, still HARSH

Current state: BFG KO2s 225/70/r16 load range C @ 28psi, Crown OEM standard duty shocks, no lift. Yes I've tried airing them down to 24psi. Maybe makes the tiniest difference, def not enough to warrant driving on a tire is clearly, visibly under-inflated and takes your foot to the floor to move it.

Are these tires really that stiff? Curious to get everyone's take. Maybe the BFGs and Ranchos are better in a larger size and lifted TJ? I can't imagine this is normal considering how much people gush about KO2s and RS5000x here. But maybe I should try a set of Michelins, but feel like I've got to be missing something here.

Pictures of your spring and shock setup would be helpful. What about the body mounts, how are those?

 

[Steel City 06]

How old are your control arm bushings? The rubber can harden up and become brittle over time. Same with other bushings, like sway bars, trackbars, steering, etc.

Also check that the slip yoke or splines on your driveshaft aren't seized up, and move smoothly. If one is seized, it can not only cause a hard ride, but also grenade the transfer case.

 

[KennethS]

I’m not sure what all you have going on, but the tire size change didn’t help. I ran the numbers using an online comparison tool and it showed the sidewall height decreased by 1.6” going to the 225-70 tires. Shorter sidewall on the lower aspect ratio tire means less cushioning.

 

[macleanflood]

Have you weighed the Jeep?

A lot of shocks are tuned for "performance" and "stability." Meaning valved for a stuff, harsh ride.

I'd get a set of Black Max shocks.

Pictures would help.

I'm a couple hours south of Portland in Fall Creek...just ran the WABDR this summer.

We really need a PNW WTF meetup.

-Mac

PS(I) Don't be afraid to run em down to 15 to 20 psi. Try it out.

 

[bucky]

Run it with the tires at 15psi. If it still rough I would think that would indicate something else. Have another TJ owner drive it and get there opinion on the ride quality. I have both a YJ and a TJRU both with 2.5” lifts. The TJ rides like a Cadillac and has 265 75 R16 KOs load range E run at 24psi. Are you hitting the bump stops?

 

[BDiddy]

I’m not sure what all you have going on, but the tire size change didn’t help. I ran the numbers using an online comparison tool and it showed the sidewall height decreased by 1.6” going to the 225-70 tires. Shorter sidewall on the lower aspect ratio tire means less cushioning.

Thanks, I was starting to think this could really be it! A shorter sidewall on LT tires intuitively had me thinking it might make things stiff. Thinking about going to 245/70/16 which looks to be very close to the 30/9.5/15 on door jam according to tire size comparison tool. Think that would improve things?

 

[BDiddy]

Pictures of your spring and shock setup would be helpful. What about the body mounts, how are those?

I can only imagine the body mounts are original. Which means 150k miles on them. Is it safe to assume they’re shot or is this more of a visual inspection item?

 

[BDiddy]

Run it with the tires at 15psi. If it still rough I would think that would indicate something else. Have another TJ owner drive it and get there opinion on the ride quality. I have both a YJ and a TJRU both with 2.5” lifts. The TJ rides like a Cadillac and has 265 75 R16 KOs load range E run at 24psi. Are you hitting the bump stops?

I really doubt I’m hitting the bump stops. We’re talking harsh jolts on 1-2” divots and bumps on paved or forest roads.

 

[BDiddy]

Have you weighed the Jeep?

A lot of shocks are tuned for "performance" and "stability." Meaning valved for a stuff, harsh ride.

I'd get a set of Black Max shocks.

Pictures would help.

I'm a couple hours south of Portland in Fall Creek...just ran the WABDR this summer.

We really need a PNW WTF meetup.

-Mac

PS(I) Don't be afraid to run em down to 15 to 20 psi. Try it out.

Dude I’m into the PNW WTF meet up idea! Most Jeepers I see up here are angry bird grill mall crawlers or sparkling new HOA drive way display pieces. Or even worse…. Gladiators. SO MANY GLADIATORS.

 

[AdelaideTJ]

Mine started off very rough as well. Bought a dead stock 2005 last year with all original fittings, bushings etc (even an 18 year old spare tyre!) New tyres, shocks and springs made a big difference in drivability, but I still have room for improvement. If none of the rubber bits have been changed since factory, as in my case, it may be time to do some of that? All control arms, trans and body mounts are next on my list. Will also do tie rod ends, steering damper, ball joints etc. Pretty much every piece of rubber underneath my TJ looks like cracked old cheese that's been left out on the counter for a week! I suspect a lot of the road shocks and vibes that get dampened by those soft parts are instead travelling right up to me in the cabin.

 

[Rickyd]

I really doubt I’m hitting the bump stops. We’re talking harsh jolts on 1-2” divots and bumps on paved or forest roads.

Look at the front and rear bump stops. You should have a few inches before they hit the lower pad. Same with the shock shafts before they bottom out.

You might also loosen all 16 control arm bolts at ride height and then tighten them up. If the suspension was tightened with it at droop like on a lift it can add to harshness as they will be severely bound up.

 

[KennethS]

Thanks, I was starting to think this could really be it! A shorter sidewall on LT tires intuitively had me thinking it might make things stiff. Thinking about going to 245/70/16 which looks to be very close to the 30/9.5/15 on door jam according to tire size comparison tool. Think that would improve things?

Why are you looking at another 70 series aspect ratio size? Go with a taller sidewall.

 

[L J]

Is this your first TJ? Have you driven or ridden in a TJ before?

 

[KennethS]

A shorter sidewall on LT tires intuitively had me thinking it might make things stiff. Thinking about going to 245/70/16 which looks to be very close to the 30/9.5/15 on door jam according to tire size comparison tool. Think that would improve things?

Absolutely a shorter sidewall will have a stiffer ride. Note that the 30x9.5 -15s have a sidewall that is 1.3” taller than the 225-70-16s (7.5” vs 6.2”). My Jeep has tires with an 8.5” sidewall.

 

[Jerry Bransford]

I can only imagine the body mounts are original. Which means 150k miles on them. Is it safe to assume they’re shot or is this more of a visual inspection item?

The body mounts don't affect ride quality.

 

[twistedlv]

Control arms were the last part of my suspension rebuild. They should have been the first. They made a huge difference in my ride quality.

 

[Jerry Bransford]

Thanks, I was starting to think this could really be it! A shorter sidewall on LT tires intuitively had me thinking it might make things stiff. Thinking about going to 245/70/16 which looks to be very close to the 30/9.5/15 on door jam according to tire size comparison tool. Think that would improve things?

First, go with an inch-size, not a metric size tire. It's harder to get the correct C Load Range with metric size tires. A 30x9.50R16 would work fine and give you more sidewall height. Usually a bone-jarring ride is caused by the shock absorbers... either too tall for the suspension lift height or the wrong type of shock like the older Rancho RS5000 or ProComp ES-3000. But you ran the RS5000x that has a great ride (for most of us) which eliminates that possibility. Are you certain you're getting shocks for a stock height TJ??? Your symptom reminds me of shocks that are too long.

Or are you coming from a passenger car and you're expecting too much from a TJ where ride quality is concerned? I will say my Lexus-driving wife thinks my TJ has a great ride, she shocked me one day on a long drive out to the desert. I was running Rancho's RS5000x shocks then with Load Range C 35's at 25 psi and a 4" suspension lift.

 

[BDiddy]

First, go with an inch-size, not a metric size tire. It's harder to get the correct C Load Range with metric size tires. A 30x9.50R16 would work fine and give you more sidewall height. Usually a bone-jarring ride is caused by the shock absorbers... either too tall for the suspension lift height or the wrong type of shock like the older Rancho RS5000 or ProComp ES-3000. But you ran the RS5000x that has a great ride (for most of us) which eliminates that possibility. Are you certain you're getting shocks for a stock height TJ??? Your symptom reminds me of shocks that are too long.

Or are you coming from a passenger car and you're expecting too much from a TJ where ride quality is concerned? I will say my Lexus-driving wife thinks my TJ has a great ride, she shocked me one day on a long drive out to the desert. I was running Rancho's RS5000x shocks then with Load Range C 35's at 25 psi and a 4" suspension lift.

Thanks Jerry, yeah I'm starting to think the tires might be it. The shocks are definitely stock height from Crown, and the Ranchos were more stiff than these. There was one time on a trip to the coast that the Ranchos on these smaller C load range ATs felt good and it was when the jeep was loaded with TONS of gear so the extra weight made a smoother ride... whether it was the shocks or tires that benefited from the extra weight I'm unsure.

Don't worry I'm not expecting anything unrealistic, just trying not to rattle my teeth out when driving in town Trying to get back to stock ride as a starting place. I recognize the TJ is a more utilitarian ride, and I love it for that.

 

[BDiddy]

Pictures of your spring and shock setup would be helpful. What about the body mounts, how are those?

A few people mentioned pictures so coming back after grabbing these in the garage. Hope it helps confirm there's nothing obviously unusual here! Like I said, I'm kind of out of ideas and thinking it might just be the super stiff but small tires.