The truth about OME shocks

long_tall_texan · **Posted:** Fri Feb 20, 2009 1:45 am

OK. Before I even start, lets not start another evil argument about bumpstops similar to the recent rash of threads that got locked.

So in another thread over here - Link - I posted my first direct response from ARB regarding whether bumpstops are needed when doing a lift with the OME springs. Then when reading thru all of the recent discussions of bumpstop theory, I saw another comment that has come up several times. It was this: OME shocks have an internal bumpstop, so that is the reason you don't have to use extended bumpstops with them... True or False???

Once again, I decided it was best to go to the source. So, here is the correspondence.

My message to ARB
-----------------------
Marc,

One more question just to clarify. From what I gathered that Stuart described in the spring explanation, the OME Spring lift actually increases overall travel of the KJ, Not just boosting ride height with the same amount of travel as stock setup. That is clear from the explanation. I would like to either verify or debunk another common thought about the OME products. Many have said that the OME front shocks for the Jeep Liberty KJ have an internal bumpstop in them. And that is why no external extended bumpstops are needed with your springs. This idea of an internal bumpstop directly contradicts what the engineer explained. So just to be clear, Do the OME front shock have an internal bumpstop to limit the upward travel more than the stock shocks?

Thanks again for your help.

Their Response
-----------------------
Hi Marc, hopefully this clears it up.

According to our documents, our shock is about 10mm longer in extension and the same as OE in compressed length. As compressed lengths are the same, we do not have anything to stop compression travel before hitting the OE bump stop. (ie. no internal bump stop)

Anything else please let me know. Cheers.

Senior Design Engineer
Old Man Emu
ARB Corporation Limited

--------------------------------

So the verdict is: FALSE. OME shocks don't have any internal bumpstops.

Just in case anyone else was wondering.

JeepinJarhead03 · **Posted:** Fri Feb 20, 2009 1:52 am

good info, i for one was confused with all the yes it is no it isn't traveling around

thanks for your investigative work LTT

tommudd · **Posted:** Fri Feb 20, 2009 2:00 am

And again conflicting messages from them, interesting, maybe we should make a trip to Aus. and do a factory tour and get some real questions answered.
See I was told that they did not recommend Ranchos as they did not have any type of built in bumpstop and would allow the spring to stack and also the shock would be destroyed, but yet with their shock that is not going to happen?
For me I will run my Ranchos and my bumpstops and be safe.

I think they want to make sure that everyone only buys their shocks and springs so they make it seem that others will fail where theirs will not, good marketing :wink:

JeepinJarhead03 · **Posted:** Fri Feb 20, 2009 2:04 am

anyone got a used emu we can destroy to find out or is it not quite that easy? :lol:

i agree with mike and tom and the other bumpstop advocates, i'd much rather it lean on a chunk of rubber or hockey puck than an internal bumpstop even if it DID/DOES have one

long_tall_texan · **Posted:** Fri Feb 20, 2009 2:08 am

That is interesting Tom. I didn't know that they had actually told you that. Was it a sales rep, tech, or passed on thru engineering?

I am not recommending one way or another. I think there is more than enough info on this site already for EVERYONE to make a wise decision about this for themselves. I was just wondering about that internal bumpstop thing.

But now it makes me wonder. Although Marc didn't answer it himself. He passed it on the the actual engineer in AUS to answer as he did with my question about the spring compression/stacking. So maybe there is some truth to this answer and not just speculation.

But I do think a LOST fieldtrip is in order for us all as you suggested. I am game. Sounds like fun!

JL Rockies · **Posted:** Fri Feb 20, 2009 3:30 am

I use rear bump stops that came with my lift kit to keep my 32" tires from ripping off my rear fenders under full stuff. I have OME front & rear.

ARBSeth · **Posted:** Fri Feb 20, 2009 6:40 pm

Ok, enough already.
There is no such thing as an internal bumpstop in our shocks/struts. I've never heard of it from any MFR.

You DON'T NEED BUMPSTOPS WITH AN OME ONLY KIT.

This is because the factory strut and the OME Strut have the same closed length. That means that under compression, the struts meet the FACTORY bumpstop at the same point, so you don't need an aftermarket set when using an Old Man Emu Strut.

That is the word from our Design Engineer in Melbourne.

Now, if you're using a Rancho Strut that is designed for a Durango on a Liberty... you may need them. The struts are constructed differently and may not meet the same spec. We here at OME try to stay as close to factory spec as we can. As always, if you use something that it wasn't designed for, you may see issues like this bumpstop thing.

So you're both right...in a way.

DryBones · **Posted:** Fri Feb 20, 2009 9:21 pm

cool, now what about the back??? same thing or do I need still need hockey pucks if I go all OME???

InCommando · **Posted:** Fri Feb 20, 2009 9:48 pm

If I am reading this right, this information will apply only to those who are running the OME lift ONLY, not a frankenlift, rockfather, or any other lift that uses a non-OME strut or that combines an OME front spring with any other method to create more lift than the OME spring/strut combo alone.

Is that the basic message in a yes/no answer format?

tjkj2002 · **Posted:** Fri Feb 20, 2009 9:59 pm

InCommando wrote:

If I am reading this right, this information will apply only to those who are running the OME lift ONLY, not a frankenlift, rockfather, or any other lift that uses a non-OME strut or that combines an OME front spring with any other method to create more lift than the OME spring/strut combo alone.

Is that the basic message in a yes/no answer format?

Something like that and that would also exclude people running the OME N132L rear shocks since they where designed for the Frankinlift.

tommudd · **Posted:** Sat Feb 21, 2009 1:05 am

and since we are not running Rancho Struts for a Durango anywhere at all on the Liberty :roll:

Boy I hope that I can still access my old email account and pull some quotes someone sent me, :lol:

tonycrd · **Posted:** Sat Feb 21, 2009 5:40 am

DryBones wrote:

cool, now what about the back??? same thing or do I need still need hockey pucks if I go all OME???

No. The OME is hardly any longer then the stock one.

Here's a pic of the rear shocks:

RANCHO----OME N132----STOCK

InCommando wrote:

If I am reading this right, this information will apply only to those who are running the OME lift ONLY, not a frankenlift, rockfather, or any other lift that uses a non-OME strut or that combines an OME front spring with any other method to create more lift than the OME spring/strut combo alone.

Is that the basic message in a yes/no answer format?

YES....and that would also mean that if you do as little as a clevis lift you void your warranty.

tommudd · **Posted:** Sat Feb 21, 2009 10:27 am

Or run the Frankenlift or any type of variation you void the warranty, anything you do except for running them straight out of the box voids the warranty which is not much to begin with anyways.

Can't blame ARB/OME though as they have lots of Lawyers to make sure they are covered from any and all things so this way they have an out.

Still funny that the story has changed over the years yet still sell the same product!

KJ04 · **Posted:** Sat Feb 21, 2009 10:50 am

tommudd wrote:

Or run the Frankenlift or any type of variation you void the warranty, anything you do except for running them straight out of the box voids the warranty which is not much to begin with anyways.

Can't blame ARB/OME though as they have lots of Lawyers to make sure they are covered from any and all things so this way they have an out.

Still funny that the story has changed over the years yet still sell the same product!

If so, then the next logical question would be: Does Al J's warranty the Frankinlift?

JJsTJ · **Posted:** Sat Feb 21, 2009 11:23 am

KJ04 wrote:

tommudd wrote:

Or run the Frankenlift or any type of variation you void the warranty, anything you do except for running them straight out of the box voids the warranty which is not much to begin with anyways.

Can't blame ARB/OME though as they have lots of Lawyers to make sure they are covered from any and all things so this way they have an out.

Still funny that the story has changed over the years yet still sell the same product!

If so, then the next logical question would be: Does Al J's warranty the Frankinlift?

Call them up and ask to be sure.

The truth about OME shocks

Who is online