'11 Rubi Unltd Susupension myths?

[redthies]

I have a set of OME coils sitting on the porch waiting for me to have a spare few hours to install. I have been reading on JKO about installs and set-up. Seems to me there is a lot of conflicting stories. The coils are the 0-90 lbs up front, and the 175 lbs for the rear. I have read stories of being unable to re-center steering wheels, limp mode, wrecked transfer cases and so on. Am I likely to see any of these issues with a 2 to 2.5" lift in an auto trans unlimited? ARB shows a lift of 1.5 to 2.5", which I take to mean 2.5 in a soft top "X"or similar, and 1.5 in a Rubicon withe the slightly taller springs from the factory.

Any wisdom for me? I can't imagine such a small lift will cause all the potential issues!

 

[JPK]

From what I have read, and I've read a lot, some Jeeps can have front drive shaft/skid plate/auto transmission pan interference, with even a 2.5" lift, when the suspension is at full droop. (The skid plate can be cut for clearence, btw, and there are several aftermarket replacement skids which have the clearence built in.)

The result of the interference is a ripped DS boot, which is there to keep in the grease needed for the splined joint where it belongs. Once the boot is torn the DS is on it way to failure, but a steady maintenance schedule seems to extend the life for some to a year and more.

If the boot tears and the shaft does need replacement, a double cardin shaft is the typical, popular remedy, but they are frought with issues, like vibration, and that is, imo, the leading candidate for the cause of transfer case failure. AEV offers a thinner front repzeppa DS that cures skid and transmission interference on 2011 and previous JK's and doesn't have the potential vibration issues.

You can test for potential interference by installing the springs and then lifting the Jeep by the frame (on a lift for safety, not a jack! IMO, not even jack stands.)

Also, if you lift the Jeep without correcting caster you will end up with flightier steering than you had pre lift. With a ~2.5" lift, this is an issue for some drivers and not for others. For example, I put a 2.5" Teraflex BB on my wife's Jeep (2.5" = 3" front and 2" rear according to TF) and I imediately noticed the flightier steering, which was a minor change, not drastic. My wife never noticed at all.

Some have reported that OME springs produce more than advertised lift. I don't know if that applies to all combinations of OME springs or not. As the end results of the lift increase, i.e. toward 3" or 3.5"... the steering issue will increase and so will the likelyhood of front DS interference.

Caster can be restored through adjustable upper or lower front control arms, or if the lift goes ~3"+ with AEV's inexpensive and inovative control arm relocation brackets. The brackets are effective and greatly reduce pinion angle issues and front driveline verticle movement. They are a bit controversial since some think they are rock magnets. I have them and they are really effective at improving ride, reducing braking dive and have yet to get whacked, but rock crawling is only an occasional use of my Jeep. AEV is coming out with a 2.5" spring lift shortly, they may have a caster correction solution with this new lift for lifts around 2.5", but their current front control arm barckets are only suitable for about 3" or greater lift.

As a last resort for caster correction, the oem lower control arms have a knock out adjacent to the rear mounting hole, which can be removed for use of cam bolts. Not a great option compared to the AEV brackets or adjustable upper or lower control arms.
Done right, lifting a Jeep causes no problems. I have AEV's 4.5" suspension on my Jeep and have had no issues after ~33k miles.

Also worth noting, my wife's Jeep has no interference issues with the TF 2.5" BB.

Hope this helps,

JPK

 

[redthies]

Thanks JPK. I figured you would have some insight with 2 lifted JKs in the stable. I don't do any "rock crawling", but there are rocks on our trails... so the AEV brackets are something I will look at if I have castor issues. The Jeep does see a lot of off road use, but our area does not usually require big articulation. I don't imagine being at full droop often, if at all. The springs will stiffen up the ride a bit so the wife will notice that I'm sure, but hopefully not any change in steering. (She probably will though as she is a very good driver). I am changing springs mainly to get increased load capacity for our trailer (as well as a bit of lift), so I hope this doesn't open a big can 'o worms!

 

[redthies]

Just saw your edit... Is the wife's a 2dr or 4dr?

 

[JPK]

My wife's is a four door, but the caster and intereference issues are common to all JK's since the front end is the same, two door or four door.

With enough lift, the two doors can have issues with the rear DS angle and so pinion and transfer case joints. But I've seen nothing that would indicate any issues with the rear DS for even two doors with ~2.5" of lift. And on my four door, there is no issue even with the 4.5" AEV suspension.

JPK

 

[Jeepin_D]

I have the OME 616/617 springs on my '08 JKU Rubi. I swapped to those springs after adding the Mopar off-road bumpers, tire swing, winch, etc. Everything else is still stock. I've done nothing for steering wheel centering, castor, etc, and had no problems with the driveline.

My interests are mainly overland travel and exploration, not rock crawling. The added weight was a little much for the factory springs. I ended up with about 1.5" of lift overall, and no rake.

I've had it like that for a couple years now, multiple trips, and no issues. The ride is a little stiffer, and overall travel is limited as your basically riding around with 1.5" of droop at all times. If you start putting on long travel shocks, extensions, etc, that's where some people have had front DS boot rubbing problems as you exceed angles dictated by factory geometry. By just changing springs and nothing else, droop is still the same as factory, limited by shocks, track bars, sway bar links, etc.

Since the JK's use a single track bar system, as the distance between the frame and axle increases, it gets shifted to one side. Like a 3-bar system making a 'Z'. The bottom horizontal of the Z is the axle, fixed by contact with the ground. Therefore if you raise the horizontal top of the Z (the frame), it has to move left relative to the bottom due to the angled part of the Z (the track bar). When it's too dramatic, that is what pushes the DS into the transmission pan. If you crawl under and look, there's not a lot of room there.

I have a Gobi rack too, and if I had any complaints, it's that when I load the JK down with gear for big trips, kayaks, etc. I still get some sag in the rear cause the springs aren't progressive. I understand that AEV will soon be releasing a complete 2" progressive coil lift, which I hope will address that problem. I will likely switch to it if so.

All I really want is the JK that rides about 2" higher, but maintains or slightly exceeds the factory travel and ride, and can handle weight. You can get close by just making subtle changes to the springs as you described, but not quite.

 

[JPK]

I have to say that I wouldn't put taller springs in without extending the shocks. Either longer shocks, which I presumed in my answer would be the good OME shocks, or at least extensions for oem shocks. The added suspension travel is nice to have even when not rock crawling.

With ~2.5" of lift the track bar isn't an issue front or rear, but if the lift is greater centering the axle might be a good idea. I suspect AEV's forthcoming kit (and it look like its going to be 2.5" from the AEV forum exchanges) will provide a relocation bracket that will be right for ~2.5-3".

The front DS/auto trans pan inteference occurs on stuff, when the compression of the "Z" forces the axle to the left looking at it from the front. Having the axle slightly displaced to the right (or the frame to the left - same thing) reduces the potential for interference. It displaces to the right when the Jeep is lifted without compensating for it (or the frame to the left as described by Jeepin D, recall its the same thing.)

BTW, you will want to check to see if you need longer bump stops to avoid overcompressing the OME springs.

JPK

 

[redthies]

Jeepin D ; Thanks for the OME info. I have the 616 fronts and 618 rears. I need the extra load capacity in the rear. Mark at ARB's tech dept figures the same as you. Shouldn't be any issues... Sometimes things don't work out that way though. I sure wish AEV had their 2.5 kit out now so I could have had another worthwhile option. As soon as the lotto numbers hit I will send the Jeep off to them for the JPK treatment!

 

[m(a)ce]

they've touched on most of the good stuff above^^^

I've run most of the different OME coils and both OME standard & lt shocks. Currently +40 coils and OME lt shocks.

With the standard shocks you shouldn't have issues tearing the ds boot on a 4dr/auto while flexing out disconnected. I did feel the setup with 618/619 coils did feel flighty. By the time I was done I added control arms. Extending the bumpstops was necessary to run 35s with the kit with stock flares.

If you add the lt shocks & components (ala Northridge) be forewarned you'll eventually tear your ds boot when you flex it.

I like the way the kit wheels off road. It's been good but definitely never felt it was complete & had to kinda piece it together & figure it all out before there was a better kit option (NR). On road I think it rides ok- would never say like or better then stock. Over rough roads it can feel a little harsh. I've been thinking about going AEV...& after installing my Gobi I think the firmness/tech of AEV might fit my needs better.

I think with the coils you're installing you'll be relatively fine with flightiness. You will need to recenter you're steering wheel but no biggie. Your ds as the guys ^^^ mentioned should be fine with your standard OME shocks. Overall the OME rides better then most kits- just not as well as the AEV I've ridden in.

Just my 2 bits.


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- Sent from the batphone using Tapatalk

 

[redthies]

The rear of our Rubi is really really soft. I cross some train tracks in a corner on my way to work and it is scary at 30-40 mph in the Jeep, but I can take the tracks at 55 or more in my Land Cruiser with OME suspension. The 'Cruiser is a bit heavier, but still solid axles and coils. I will try to get the coils in later this week and report the findings once I have a few miles on them

 

[JIMBO]

:sombrero: My '08 JKUR has (last two No.s) 19s front/60s rear-/2.5" RC lift/RS9000XL (adj) shocks-

Running weight 4700 lbs-

She doesn't lean on corners/bunce on bumps (railroad tracks) and rides as stiff as I wantit to

75% of your trouble in ride/rebound is SHOCKS-

:costumed-smiley-007:wings: JIMBO

 

[redthies]

So the coils are in, and it gained a fair bit of height. I, for the umpteenth time, forgot to measure pre-lift height. Some day I will remember to measure before I lift... It rides better according to my wife, but still not as good as any of our Toyotas. Maybe different shocks will help. Time will tell. The only thing I've noticed is rear axle is slightly off set due to no drop bracket. Otherwise, it drives great!