Shock Orientation

slikjr · **Posted:** Mon Jun 25, 2007 8:31 pm

So here's a question for all you people who are smarter than me...

I just installed my ProComp ES3000 shocks. I had Rancho RS5000 before but they were far too rough riding. A lil' FYI, these ProcComps are amazing! They are a much smoother and more responsive shock. Love them!!

Anyways, when installing them, a question arose. Both the stock KJ shocks and the Ranchos had a "sleeve type" boot on them (shock rod covered with sleeve). The stock shocks are mounted with the "fatter" end up, so the "rod" of the shock up which is covered by the sleeve boot. I mounted my Ranchos the same way because they were the same set-up. The ProComps didn't come with any boots. So, I mounted them the opposite way. So the "rod" is attatched to the bottom and the "shock" to the top. This seemed to make sense because of our lil' friend gravity and crap sliding down the rod and off rather than sitting on top of the shock.

Is there any difference in performance? Pros and cons? And, do boots make any difference, or just for looks? If you can help me out, please post!! Thanks a lot!

GilaMonster · **Posted:** Mon Jun 25, 2007 9:00 pm

slikjr wrote:

So here's a question for all you people who are smarter than me...

I just installed my ProComp ES3000 shocks. I had Rancho RS5000 before but they were far too rough riding. A lil' FYI, these ProcComps are amazing! They are a much smoother and more responsive shock. Love them!!

Anyways, when installing them, a question arose. Both the stock KJ shocks and the Ranchos had a "sleeve type" boot on them (shock rod covered with sleeve). The stock shocks are mounted with the "fatter" end up, so the "rod" of the shock up which is covered by the sleeve boot. I mounted my Ranchos the same way because they were the same set-up. The ProComps didn't come with any boots. So, I mounted them the opposite way. So the "rod" is attatched to the bottom and the "shock" to the top. This seemed to make sense because of our lil' friend gravity and crap sliding down the rod and off rather than sitting on top of the shock.

Is there any difference in performance? Pros and cons? And, do boots make any difference, or just for looks? If you can help me out, please post!! Thanks a lot!

My Ranchos are mounted with the rod up top and the fat part mounted to the axle. There is a dust boot too, this is what the sleve was on the stock shock, and it was mounted with the rod end up top.

Jeepjeepster · **Posted:** Mon Jun 25, 2007 9:28 pm

The rod may need to go up.. Usually the shock wont even do its job as a shock when you have it upside down.. Does it bounce alot?

renegadekj · **Posted:** Mon Jun 25, 2007 10:13 pm

Try to go over a speed bump and see if it bottoms out or bounces alot!... There was a guy on here that installed his upside down and couldn't figure out why it was bouncing so much and was bottoming out over speed bumps,well sure enough he installed them upside down(same way you did). They probbaly seem very "plush" don't they?They are not made to go on that way so i would change them.

Green Renegade · **Posted:** Mon Jun 25, 2007 11:32 pm

I may be wrong here, but from what I learned in system dynamics, a shock is just a velocity damper, which resists motion in either direction. If they had a right and wrong way, that would lead me to believe that they only provide damping in one direction. So your springs are only damped in tension and not compression or vice versa. It seems more likely to me that they should work in both directions, and therefore not have a right or wrong way to be mounted. I know I've seen them mounted both ways in 4x4 magazines.

tjkj2002 · **Posted:** Mon Jun 25, 2007 11:40 pm

Green Renegade wrote:

I may be wrong here, but from what I learned in system dynamics, a shock is just a velocity damper, which resists motion in either direction. If they had a right and wrong way, that would lead me to believe that they only provide damping in one direction. So your springs are only damped in tension and not compression or vice versa. It seems more likely to me that they should work in both directions, and therefore not have a right or wrong way to be mounted. I know I've seen them mounted both ways in 4x4 magazines.

They dampen both direction,both compression and rebound.It depends on the shock on how they are orientation,some have the shock shaft up and some have it down.Resivoir shocks,bypass,and air shocks all have the shock shaft on the bottom side.The SkyJacker front struts(really just shocks) where reversed to how the OME,Rancho's,and stock one are facing.

Weegie5 · **Posted:** Tue Jun 26, 2007 12:23 am

Green Renegade wrote:

I may be wrong here, but from what I learned in system dynamics, a shock is just a velocity damper, which resists motion in either direction. If they had a right and wrong way, that would lead me to believe that they only provide damping in one direction. So your springs are only damped in tension and not compression or vice versa. It seems more likely to me that they should work in both directions, and therefore not have a right or wrong way to be mounted. I know I've seen them mounted both ways in 4x4 magazines.

You're right to a point- they do dampen in both directions. My understanding is that the "bottle" of the shock is not completely full of fluid. (I could be wrong on this, but it would explain why there is a right side up.) If the "bottle" was full, there would be no right side up. As it is, if the shock is installed upside-down, enough of the fluid drains below the damper orfice(s) in the shock and you get minimal or no damping.

Oh the joys of Vibration Analysis and DiffEq. Man am I glad I've never had to use that crap!

Jeepjeepster · **Posted:** Tue Jun 26, 2007 12:50 am

System dynamics taught you right but what they didnt teach you is how a shock is made. Sometimes the valving isnt made to be used upside down and will not dampen correctly.

tjkj covered that though..

tjkj2002 · **Posted:** Tue Jun 26, 2007 12:57 am

Jeepjeepster wrote:

System dynamics taught you right but what they didnt teach you is how a shock is made. Sometimes the valving isnt made to be used upside down and will not dampen correctly.

tjkj covered that though..

It also depends on what is inside the shock,some are twin tube/oil,twin tube/gas charged with oil,mono tube/oil,mono tube/gas charged with oil.There are many types of shocks,some shocks(true air shocks) have to oil or valves in them and some do not require a spring either,you just use the air shock as both.

slikjr · **Posted:** Tue Jun 26, 2007 7:12 pm

Ok, so what I have learned thus far is... too many different opinions! ahaha... I aprreciate all the input though.

I agree with the statement about "dampening". I also thought they were a damper for the spring so it really wouldn't matter what way they mounted. As I said in my first post, because I thought it made ne difference, it seemed better this way so they crap would "slide" off easier.

I am going to phone JustJeeps.com in Toronto right now and see what they have to say on the matter. I will repost when I hear back and fill you all in. Thanks again

tjkj2002 · **Posted:** Tue Jun 26, 2007 7:18 pm

Quote:

I also thought they were a damper for the spring so it really wouldn't matter what way they mounted. As I said in my first post, because I thought it made ne difference, it seemed better this way so they crap would "slide" off easier.

They are a damper for the springs but it depends on the shock construction and what is inside the shock which determines the orientation.90% of the shocks have the shock shaft pointing up,the higher end performance shocks can be(not always) the opisite way.

slikjr · **Posted:** Tue Jun 26, 2007 7:28 pm

Ok, JustJeeps.co is closed for the night so they are of no use today. I will call them in the morning and repost their answer tomorrow after work. Also, I emailed ProComp directly and explained it all. We all know how companies are at getting back to web based questions so... when the wait is over and they get back to me, I will post that as well! Until then, I wait and wait

slikjr · **Posted:** Tue Jun 26, 2007 7:40 pm

Ok, JustJeeps.co is closed for the night so they are of no use today. I will call them in the morning and repost their answer tomorrow after work. Also, I emailed ProComp directly and explained it all. We all know how companies are at getting back to web based questions so... when the wait is over and they get back to me, I will post that as well! Until then, I wait and wait

ATXKJ · **Posted:** Tue Jun 26, 2007 7:46 pm

From a Theory standpoint - a perfect shock would be ~ 90% rebound damping and 10% compression damping -the spring should resist compression - not the shock - it should dampen on rebound. Doesn't always work that way, but that's the theory.
However that doesn't affect which end goes up - that's determined by the internal construction - gas/oil mix valving ect. if it was designed for the valve body to be down and it's up - you'll have problems or if it's designed to be up and it's down - you'll have problems. So install it the way the manufacturer says.

tjkj2002 · **Posted:** Tue Jun 26, 2007 7:56 pm

slikjr wrote:

Ok, JustJeeps.co is closed for the night so they are of no use today. I will call them in the morning and repost their answer tomorrow after work. Also, I emailed ProComp directly and explained it all. We all know how companies are at getting back to web based questions so... when the wait is over and they get back to me, I will post that as well! Until then, I wait and wait

Here is some shock info from some manufactures----

http://www.bilstein.com/tech.php?PHPSESSID=275d353b6a52807ade9b7b60afae3387

http://www.arbusa.com/shock_absorbers_ltr.php

http://www.arbusa.com/nitrocharger/shock_absorber_ome_nitrocharger.jpg

[url][url]http://www.koni.com/index.php?id=318[/url][/url]

http://www.koni.com/index.php?id=317

http://www.koni.com/index.php?id=58

http://www.koni.com/index.php?id=71

jason thompson · **Posted:** Tue Jun 26, 2007 9:30 pm

what I know about shocks is limited
I do know how ever that guys with TJ's and rolled up diffs ,pinion angle pointed up they have to do 1 of 2 things
get shocks that can go up side down
or
get shock shifters
this is needed to keep the shock from being damaged by the spring buckets if they could just put them on upside down then trust me they would

Knowing that I would say that you should put them on "correctly" piston up
like they were probably made to be

slikjr · **Posted:** Wed Jun 27, 2007 12:56 am

Ok, so in the few minutes I had to check tonight (busy night)... the back end seems to be very bouncy. I would say the shocks are doing very little. I stood on the bumper and bounced it (I weigh 170 or so) and it was bouncing like crazy. Driving it seemed to be all over the place... real loose. Like a suspension link was almost disconnected. I don't know.... maybe it was just me being parranoyed.

I think I have them on upside down. I think they need to go "bottle" part DOWN. Again, I will repost tomorrow when I get the information from JustJeeps and ProComp. Thanks for all the input y'all. Looking forward to getting some confirming info from the manufacturer and the supplier. I'll post
'

cmohr · **Posted:** Wed Jun 27, 2007 2:54 am

Hey, All.

I've got the Pro-comps.... Shaft at the TOP. "Bottle" at the bottom. And yyes, you need a dust boot on there. Maybe just use the old ones off your Ranchos.

Oh, and Yes!!! They are a great shockie

I had the Old Man Emus. they lasted about 2weeks on some of the real rough roads here in Oz. Pro-comps...going strong!

cmohr

slikjr · **Posted:** Wed Jun 27, 2007 7:53 pm

Final word... here it is!!!

First, I called JustJeeps.com in Toronto where I purchased the shocks. They were very helpful and told me they go "BOTTLE DOWN".

I emailed ProComp directly and they got back to me the next day!! WOW! That from a big company, huge respect gained. Here is the email from them:

Hi TJ, the ES3000 shocks must be mounted with the shaft end up “bottle” or white body down, since they are a twin tube shock with a fluid control valve in the bottom of the shock.

Jeff Blakely

Pro Comp Suspension

Tech Support

800-776-0767 ext 117

So, there is some knowledge gained for all of us who were guessing ourselves. And thanks to all for the feedback! Me and the KJ appreciate it!

Shock Orientation

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