I recently installed a lift on my JK. Today, while going over a speed bump in a parking lot, I think I may have bottomed out. I was going slow when I hit the speed bump, but I wasn't creeping over it. I don't know how explain it, other than it was sort of a bone-jarring slam. It only happened when the front end of the Jeep went over the speed bump (not the rear). When I creeped over the next speed bump, it was smooth.

Here are the details of my setup: I have 1.75" coil spacers in the font, extended bumpstops, and Old Man Emu Shocks that are for a 2" lift. Now I don't think that it was the shocks bottoming out, because the OME shocks are only about 1/2" longer. OME shocks are supposed to be 22.5" extended and 15" compressed. My stock shocks are approx. 22" extended and 14.5" compressed. I'm thinking that the problem might be the bumpstops. The bumpstops are 1.75" longer than the stock ones were, which seemed right to me since I installed 1.75" spacers. But this left me with only about 2" clearance underneath the bumpstop. I'm thinking maybe it was the bumpstop that hit bottom, so I'm wondering if I should cut off some of the length. I did some searching on here, however, and found where another person with a 2" lift reported only having 2" clearance under the bumpstop, and people told him it was normal. So now I'm not sure.

Sorry to go into so much detail, but I know there are a lot of very knowlegeable people on this forum, so I'm hoping someone might shed some light on exactly what the problem might be.

 

That sucks i can't even imagine that sound on my JK. I would cry throw a hissy fit after hearing that. I agree with 2k2wranglerx above. Call and Return

 

What kind of diff guards do you have and did you check to see how much clearance you have between it and your front track bar? Are there any signs that the two have made contact? That's where I would start looking as it is a common problem.

 

I have this diff. guard in the front (although this is a picture of the rear):



I checked the diff. guard, and it shows no sign of impact (i.e. no scratches, scrapes, etc)

Here is a pic showing the OME shocks compared to the stock shocks:



The stone guards on the OME are shorter, kind of giving the appearance of the shocks being a lot longer, but if you look at the overall length, the OME shocks are not that much longer. I compressed both shocks (stock and OME) and there is very little difference in the compressed lenths (about 1/2"). Since I have 1.75" lift in the front, the OME shocks seem to be about the right length to me, plus they're made for 2" lift.

When I hit the speed bump, the bone-jarring hit was when I first hit the speed bump (i.e. on the downward movement of the front end of the vehicle). When it rebounded (on the upward movement), it was fine. That's why I thought that the bumpstops might have bottomed out. I'm not sure though.

David at Northridge explained to me that the OME shocks are progressive, and that they get firmer when you hit with more force, but I really don't think that's what's happening, because the front end seemed to dive slightly and I think if it were the shocks stiffening up, there wouldn't be much, if any, front end dive.

I had a '93 YJ with Skyjacker suspension and Rancho RS5000 shocks. It was stiff to say the least. I'm using this to compare, because when I hit the speed bump in the JK, it sort of reminded me of the old YJ. My husband was with me when this occured, and he was also shocked, because the JK has always been so smooth over any kind of bump. He thought that it felt like we bottomed out.

Again, I've probably provided way to much information, but I'm hoping it might help me figure out what caused it.

 

what size tires are you running, if they're only 33s i would say put the stock bump stops back in since you can clear 33s stock. then go to the same speed bump and go over it at about the same speed to see if its still happening. If not, you know its the bumpstops bottoming out. its that solves your problem, i would cut your new bumpstops to be 1/2" longer than the originals to protect your shocks at full compression since they're 1/2" longer than the originals. If the swapping of bumpstops doesn't fix the issue, then its back to the drawing board. But i have a good feeling it might be that. I went over a good bump in the road once with a little speed and had the same happen to me back when it was still stock, scared the hell out of me. But now i run 4 3/4" of lift in the front and factory bumpstops (the new shocks have built in bumpstops so new ones aren't needed) and i can fly over just about anything without bottoming out, not that i do, but i could if i was dumb enough to go baha-ing through the local speed bump areas.

anyway, i hope that helps, good luck

 

Damn, their lift shocks only give 7.5" of travel?

No wonder OME's articulation didn't look that good.

Are you sure those are the right shocks for the lift?

As the OME are so close in size to the OEM shocks, its doubtful that the shocks would be too long on compression....unless,

....anyone know the compressed / extended lengths of the Stock Shocks?

 

Well that's what I was thinking, that the OME shocks are not too long when compressed, so I would think it must be the bumpstops or somthing else.

OME front shocks are supposed to be 22.5" extended and 15" compressed. Stock front shocks are approx. 22" extended and 14.5" compressed.

 

That's Bizarre.

My Xterra is running 17 - 29" BIlsteins with 12" travel, and the stock on the X was about 14 - 23" (~ 9" travel...)

( JK on order from 9/07)

 

Just took a pic:



There is about 2" clearance below the bumpstop. I'm wondering if my bumpstops might be too long.

 

Yeah, I was thinking they looked kind of long for my lift. I may test it out next weekend off road to see for sure, but it looks like I may be able to cut some off the bottom without removing the coils. The only difficulty might be getting the piece I cut off out of the coil.

This afternoon we rotated my tires. Afterwards, I drove down my street, which has a couple of those small dips for drainage. I noticed that when I hit the dips, the front suspension seemed a bit harsh, but it was definitely not bottoming out. So maybe it is just the progressive nature of the shocks. When I slow down and creep through the dip, it's smooth. The rear, however, is smooth at any speed. Maybe I just have to get used to the shocks--not sure.