Broken Rear Upper Shock Mount? [Archive] - JKowners.com : Jeep Wrangler JK Forum

: Broken Rear Upper Shock Mount?


jkdrone
02-01-2009, 11:12 AM
Anyone else break theirs?

Walked out of restaurant at lunch, saw my rear shock sitting kinda funny. Made me stop in my tracks, get under there and look - and sure enough, the top of the shock (rear driver's side) is free floating and sitting next to the muffler. Notice the upper mount is just hanging there, completely free on one side with the bushing on it. Grab the mount, and the other side breaks free with a single pull.

My first thought was that someone in a little car ran into me, but there were no marks in the dirt on the shock, except where it was rubbing on the brake cable, and the scratches on my muffler indicated that I had been driving with it.

Funny enough, hardly noticed a difference in the ride, except the rear corner rolls a bit more (had to get it home, somehow), and of course, the sound of my shock banging on the muffler.

Anyone else break theirs? These shock mounts are clearly junk - are there any upgraded options?

I'll post pics in a bit. FWIW, I have a skyjacker 2.5" lift kit on it (shocks, springs, etc.)

!c

jkdrone
02-01-2009, 12:04 PM
Pics:

Mount w/ bushing on it:
http://www.dronecolony.com/2008/new_img/jk/broke_sm/P2010059.jpg

Mount w/ bushing off: (short side broke first)
http://www.dronecolony.com/2008/new_img/jk/broke_sm/P2010060.jpg

Mount location:
http://www.dronecolony.com/2008/new_img/jk/broke_sm/P2010062.jpg


http://www.dronecolony.com/2008/new_img/jk/broke_sm/P2010063.jpg

http://www.dronecolony.com/2008/new_img/jk/broke_sm/P2010064.jpg

FWIW, I just removed the shock - going to have to drive it like this (carefully) until I can get a new mount and bushing, hopefully can take care of both tomorrow.

!c

SDMF
02-01-2009, 12:33 PM
If you want to ditch the bar pins poly makes a nice bracket. I have it myself and it works very well.

http://www.polyperformance.com/shop/Poly-Performance-Jeep-JK-Rear-Upper-Shock-Mount-Kit-p-16757.html

jkdrone
02-01-2009, 12:37 PM
If you want to ditch the bar pins poly makes a nice bracket. I have it myself and it works very well.

http://www.polyperformance.com/shop/Poly-Performance-Jeep-JK-Rear-Upper-Shock-Mount-Kit-p-16757.html


Holy cow - those're cheaper than _one_ replacement mount from Mopar ($90). I wonder how fast I can get 'em shipped? Don't want to run on three shocks for very long.

!c

WTF_LOL
02-01-2009, 01:59 PM
lol, when I first started reading this I thiught you were talking about the mounting bracket itself!

Yah, those bar pins suck. x2 on the poly bar pin eliminators

JKS has one out now to which I like a little better

http://store.jksmfg.com/merchant2/merchant.mvc?Screen=BARPINELIM&Store_Code=JKS01&Category_Code=Shock

I think I will be getting these ones and some washers to go between the bushing and the mounts. Kinda surprised they don't come with them with how it preloads

https://www.quadratec.com/Assets/Images/108701/108701-md.jpg

WTF_LOL
02-01-2009, 02:04 PM
Actually, I was just thinking about it, even though the JKS is slightly cheaper, I think the POly ones would be easier to swap out shocks as you would not have to mess with the bolt above the mount. Gues I will be getting the poly ones

jkdrone
02-01-2009, 02:23 PM
Rockrash 4x4/Redneckhouston has taken care of me - I'm going to go pick up a pair of the poly ones from him tonight. Of course, one is left to wonder as to how one of these breaks driving on the street - so we're going to look into that too, maybe the bumpstops aren't doing their job.

I was just kinda shocked (lol) to see my shock laying on the ground when I came out of lunch!

I like the JKS ones, but I agree that the poly's look much easier to deal with. And, the polys are what I can get tongiht =)

!c

bodyguy
02-01-2009, 05:39 PM
its not a bump stop issue but more of using the shocks for limiting suspension droop. Reason I say that is under compression the shock would be pushing the bar against the bracket not really putting it under too much stress. When the shock is being used to limit droop the bar is being pulled away from the mount and only the bolt heads are offering the support which isn't that big of an area. my 2 pennies

StubEXrube
02-01-2009, 06:05 PM
Of course, one is left to wonder as to how one of these breaks driving on the street...

Also...It's possible that the stress related failure could have happened while wheeling, It could have been already fractured and/ or weakened...and finally just broke completely through while on the road.

redneckhouston
02-01-2009, 07:41 PM
its not a bump stop issue but more of using the shocks for limiting suspension droop. Reason I say that is under compression the shock would be pushing the bar against the bracket not really putting it under too much stress. When the shock is being used to limit droop the bar is being pulled away from the mount and only the bolt heads are offering the support which isn't that big of an area. my 2 pennies


judging from the pics ....the direction of the break.....i agree 100%

jkdrone
02-02-2009, 06:56 AM
Well, it appears the shock is shot as well - it's gritty, nasty, and sticks in a spot when compressing and expanding it. There is also a spot where the shock came into contact with the skyjacker trackbar relocation bracket.

The current working theory I had (until reading this now) is that the shock hit the bracket and bent, and was not compressing/releasing properly causing the eventual failure of the bar pin.

Of course, now I'm wondering if that's right. But, if using the shocks to limit droop is the problem, what can be done to rectify that? Using shorter anti-sway links in the rear?

I'm about to drop some $$ on new MX6 shocks (I hate those skyjacker ones anyhow) - and don't really just want to throw it away and have those f-up too. Would like to solve the primary problem. Going to order an adjustable track bar for the rear too.

!c

RoCk-NeSs MoNsTeR
02-02-2009, 07:26 AM
Well, it appears the shock is shot as well - it's gritty, nasty, and sticks in a spot when compressing and expanding it. There is also a spot where the shock came into contact with the skyjacker trackbar relocation bracket.

The current working theory I had (until reading this now) is that the shock hit the bracket and bent, and was not compressing/releasing properly causing the eventual failure of the bar pin.

Of course, now I'm wondering if that's right. But, if using the shocks to limit droop is the problem, what can be done to rectify that? Using shorter anti-sway links in the rear?

I'm about to drop some $$ on new MX6 shocks (I hate those skyjacker ones anyhow) - and don't really just want to throw it away and have those f-up too. Would like to solve the primary problem. Going to order an adjustable track bar for the rear too.

!c

Do not use shorter links in the rear. Limiting straps are your answer.
http://www.polyperformance.com/shop/Poly-Performance-Limit-Strap-p-47.html

jkdrone
02-02-2009, 07:49 AM
Do not use shorter links in the rear. Limiting straps are your answer.
http://www.polyperformance.com/shop/Poly-Performance-Limit-Strap-p-47.html

Interesting. What would be the preferred method for sizing such straps?

!c

bodyguy
02-02-2009, 02:36 PM
Install your shock measure how much of the piston rod is showing (static ride). Remove the shock and fully extend it and measure the full length of the piston rod and subtract the static ride length of the piston rod. Find a mounting location for the limiting strap on the axle and frame. Measure the distance between the mounting locations and then add the measurement you have from the piston rod length. Once you have that measurement subtract one to two inches. I hope this makes sense

jkdrone
02-02-2009, 02:39 PM
Install your shock measure how much of the piston rod is showing (static ride). Remove the shock and fully extend it and measure the full length of the piston rod and subtract the static ride length of the piston rod. Find a mounting location for the limiting strap on the axle and frame. Measure the distance between the mounting locations and then add the measurement you have from the piston rod length. Once you have that measurement subtract one to two inches. I hope this makes sense

Makes perfect sense. I found an article earlier that referenced bringing it to full-flex in a shop w/ the vehicle on jack-stands and using an engine hoist, heh. This sounds a lot more reasonable =)

!c

bodyguy
02-02-2009, 02:53 PM
Makes perfect sense. I found an article earlier that referenced bringing it to full-flex in a shop w/ the vehicle on jack-stands and using an engine hoist, heh. This sounds a lot more reasonable =)

!c

Glad to help :beer:

PhilD
02-02-2009, 03:58 PM
Do not use shorter links in the rear. Limiting straps are your answer.I agree on not using shorter links, to keep your sway bar geometry right the ends of the sway bar should be parallel to the ground, or close to. Shorter links would mess this up. Rather than using limit straps though I'd personally use shocks with a longer extended length. My shocks are not the limiting factor in suspension travel, rather the sway bars and control arms are.

I use JKS bar pin eleminators for the rear uppers also. Some of the shock pins, like the Fox ones are sold and will not break easily, hwoever I found that the shocks would slide down the pins to one end, so JKS bar pin eleminators work better.

RotorHead
02-02-2009, 04:22 PM
I agree on not using shorter links, to keep your sway bar geometry right the ends of the sway bar should be parallel to the ground, or close to. Shorter links would mess this up. Rather than using limit straps though I'd personally use shocks with a longer extended length. My shocks are not the limiting factor in suspension travel, rather the sway bars and control arms are.

I use JKS bar pin eleminators for the rear uppers also. Some of the shock pins, like the Fox ones are sold and will not break easily, hwoever I found that the shocks would slide down the pins to one end, so JKS bar pin eleminators work better.

I would not advise using your sway bar to limit down travel. The sway bar can reverse and cause damage to your calipers. I had my shock mounts moved up by a shop and they went farther than I wanted them to. The sway bar reversed on the trail and I broke a bleeder screw off giving me no brakes. Not fun. Luckily I was able to seal the leak after removing the links. I now have the Poly lower relocation bracket and all is good.

http://i187.photobucket.com/albums/x164/SeminoleMike/Jeep%20Pictures/SANY1447.jpg

http://i187.photobucket.com/albums/x164/SeminoleMike/Jeep%20Pictures/SANY1448.jpg

PhilD
02-02-2009, 05:06 PM
I would not advise using your sway bar to limit down travel. The sway bar can reverse and cause damage to your calipers. I had my shock mounts moved up by a shop and they went farther than I wanted them to. The sway bar reversed on the trail and I broke a bleeder screw off giving me no brakes. Not fun. Luckily I was able to seal the leak after removing the links. I now have the Poly lower relocation bracket and all is good.Thanks for the info, useful to know. It hasn't happened to me yet and I've looked at the rear good when it's fully flexed out and don't see it happening either. My shocks would bottom out before the sway bar links flipped, and the link/control arm combo stop my shocks from bottoming out. When flexed hard I'm sure the shock may bottom out, but the force on them will be minimal by that point.

The Poly sway bar links are long enough to keep the sway bar ends level at rest, as they should be, and as a result at full flex they are nowhere near flipping over. I can see it happening if the links are on the short side, but not if they are long.

RotorHead
02-02-2009, 07:35 PM
Thanks for the info, useful to know. It hasn't happened to me yet and I've looked at the rear good when it's fully flexed out and don't see it happening either. My shocks would bottom out before the sway bar links flipped, and the link/control arm combo stop my shocks from bottoming out. When flexed hard I'm sure the shock may bottom out, but the force on them will be minimal by that point.

The Poly sway bar links are long enough to keep the sway bar ends level at rest, as they should be, and as a result at full flex they are nowhere near flipping over. I can see it happening if the links are on the short side, but not if they are long.

Yeah, my teraflex non-adjustable links leave the rear sway bar slightly down at rest in the rear, but the main point is that you don't want your sway bar to ever reach a near straight line with the links when drooped. Under normal conditions the rear sway bar wouldn't droop to the point that it could flip, but when they relocated my lower shock mounts, they moved them up about 4". I had to droop the whole axle perfectly in order to make them flip. On Rubicon models, because of the disconnect, you can do this by just drooping one side in the front, but on the rear you would need to droop both sides.

The Poly bracket I installed after that put them about 2" above stock. I am good now.

Thanks for the new brackets Phil.

Just so you all know. This was an install error on my part or at least the shop I payed to make the mod, but it is something we should all be aware of. Make sure your sway bar links are long enough to accommodate your travel length in both directions.

Notice the mount location before installing the Poly bracket:
http://i187.photobucket.com/albums/x164/SeminoleMike/Jeep%20Pictures/SANY1448.jpg
After cutting off the bracket, grinding and installing Poly Performance bracket:
http://i187.photobucket.com/albums/x164/SeminoleMike/Jeep%20Pictures/Poly%20Performance%20Rear%20Shock%20Mount/SANY1599.jpg

jkdrone
02-03-2009, 09:24 PM
Ok, so I got them mounted and with new MX6 shocks in the rear. (Haven't done the front yet.)

As a complete mistake, I ordered the wrong part #, and got the shocks for up to 2". I measured the skyjackers and the mx6, and with the extended length of the brackets vs. the bar pins, I only lost about 1/2" of travel. But, the skyjacker shocks were completely blown at 17k miles (ok, so I drive on really rough streets, and the rocks don't help too much either =). So the ride in the rear is like new.

All-in-all a bit of a pain in the butt trying to do it in my parkign lot w/ just the spare jack, but it got the job done.

For those installing the BPE's from poly: it's all pretty obvious, except: the shock has to be installed in the bracket first, as there isn't enough room to put the bolt through when you've mounted the bracket. (Whoops.) And leave the washer off on the nut side of the bolt, otherwise you won't be able to get the allen-head mounting bolt in-place.

!c

seal20
02-11-2009, 01:53 PM
I bought the JKS ones initially but they are only compatible with 5/8" shock eyes...the Fox Racing shocks I have are 1/2" so i went with the Rough Country set for $19.99 and made them work! They are very similar to the poly ones.

http://www.roughcountry.com/jeep_xtras_barpin-eliminator.html