OME springs A and B sides
- Thread starter TurboTJ
- Start date
When I installed my OME kit I found the below from ARBs website:
SPECIFICATIONS
A/B Fitment
As a general rule, the A springs have a higher free height than the B coils. This is to allow the fitter to compensate for driver weight, aftermarket accessories, vehicle weight distribution, and chassis twist. We suggest taking measurements at each corner before fitting the new suspension components. This will allow for more accurate A/B fitment.
In vehicles with front and rear A/B springs, most of these vehicles will be happiest with an A coil fitted to the front, driver corner and the opposite rear, passenger corner. In vehicles with only rear A/B springs, most will end up with the A spring on the rear, driver corner.
It must be understood that due to the A/B variation, the first spring selection may result in the vehicle to be unlevel. If this is the case, swapping spring locations is necessary before trying other trimming methods
SPECIFICATIONS
A/B Fitment
As a general rule, the A springs have a higher free height than the B coils. This is to allow the fitter to compensate for driver weight, aftermarket accessories, vehicle weight distribution, and chassis twist. We suggest taking measurements at each corner before fitting the new suspension components. This will allow for more accurate A/B fitment.
In vehicles with front and rear A/B springs, most of these vehicles will be happiest with an A coil fitted to the front, driver corner and the opposite rear, passenger corner. In vehicles with only rear A/B springs, most will end up with the A spring on the rear, driver corner.
It must be understood that due to the A/B variation, the first spring selection may result in the vehicle to be unlevel. If this is the case, swapping spring locations is necessary before trying other trimming methods
OP
Is the longer A spring on the rear put on the passenger side to counteract driveline torque would tend to compress the spring on that side?
OP
It amazing how much misinformation there is on the web about this. Some say both A springs on the drivers side. Some say the opposite. Few are aware of the OME recommendation for front driver’s side A and rear passenger side A. I currently have both A springs on the driver’s side and the Jeep is dead level, but that may not be optimum. I am about to change my LD springs out for HD springs and will follow the OME recommendation, at least initially. I will report back on the results.
Daniel Kellogg
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MountaineerTom
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That is the bummer about OME lifts. I have actually fought that too. I am also installing one on wifees jeep this weekend. The bummer is, that it is the only lift that you put on and then may have to take it back off and move things around.
When I was doing my lift I actually called ARB and they said the lift comes with spacers. and you put them all in and do the rear driver b pass A then the opposite in the front, and if it isn't level take it apart and swap things and maybe add or remove spacers. The rear is fine, but the front kind of sucks.
They told me that it is build for right hand drives in Australia and in the right hand drives both the longer ones go on the driver side, which is our passenger side, so it would make sense for me that both the longer ones should go on the driver side. I would assume the longer ones are for the driver weight.
It doesn't make sense to me that they put the longer springs for the torque because that seems like it would only level out when you take off or really get on the gas in other situations it would not be level.
All that said I put mine on diagonally. If it isn't level, I will probably leave it and see if it settles and later if I get too much OCD I may swap them (Wifees Jeep). I don't believe she weighs enough to level out if I put both tall ones on the same side.
Anyway, good luck I hope we both are lucky enough to get it right the first time.
Everybody I know that doesn't have a OME are level. I don't see where they are off at all, but the OME is the best riding 2 inch lift, and I recommend it despite all of the work it takes to get it right.
Once you get it dialed in, you wont be sorry. I am excited to get wifees TJ done because the lift that was on it was horrible. I think it is going to be like a brand new jeep again when I get done with it.
When I was doing my lift I actually called ARB and they said the lift comes with spacers. and you put them all in and do the rear driver b pass A then the opposite in the front, and if it isn't level take it apart and swap things and maybe add or remove spacers. The rear is fine, but the front kind of sucks.
They told me that it is build for right hand drives in Australia and in the right hand drives both the longer ones go on the driver side, which is our passenger side, so it would make sense for me that both the longer ones should go on the driver side. I would assume the longer ones are for the driver weight.
It doesn't make sense to me that they put the longer springs for the torque because that seems like it would only level out when you take off or really get on the gas in other situations it would not be level.
All that said I put mine on diagonally. If it isn't level, I will probably leave it and see if it settles and later if I get too much OCD I may swap them (Wifees Jeep). I don't believe she weighs enough to level out if I put both tall ones on the same side.
Anyway, good luck I hope we both are lucky enough to get it right the first time.
Everybody I know that doesn't have a OME are level. I don't see where they are off at all, but the OME is the best riding 2 inch lift, and I recommend it despite all of the work it takes to get it right.
Once you get it dialed in, you wont be sorry. I am excited to get wifees TJ done because the lift that was on it was horrible. I think it is going to be like a brand new jeep again when I get done with it.
It actually is really easy to install if you are mechanically inclined. Here are a couple of suggestions in things you may fight.
First you will have to add a bracket on the rear end to lift the rear track bar a bit. People argue that this is tough, but here is what I find that makes it easy. Take the bar completely out when starting the lift in the rear. (I always to do the rear first because it is the easiest and fastest in my mind.) Then remove the shocks completely off. Then pull the springs out. then drop the rear end as far as it will go. (Don't worry the control arms are still holding it and they won't let it go too far, but at this point bold the rear bracket where it goes. It is pretty straight forward where and how it goes. Get it just snug, then you will have to drill two small holes for two smaller nuts and bolts. If you do what I suggest you have ample space to get a cordless drill in there to drill both of the holes. I know some people fight that I am not sure why, but that part didn't trip me out.
Second After putting the bracket and after cycling the suspension, put your springs and shocks and bumpstops in if necessary (I almost always need at least 1" bumpstop in the rear)(By the way the bumpstops don't come with bolts, but if you only need one bumpstop you can use the same bolt that holds the jounce.) Now here is what I found a tough part that is somewhat easy if you do it my way. Bolt the rear track bar to the new bottom bracket you installed in my first paragraph get snugish. then after everything else is done jack the diff up and the track bar will come super close to lining up on the frame side. You will have to play with it to find the sweet spot. The other thing I have done is put the tires on and set the tj down then put the bolt on with the weight of the jeep, but if you are a little off it makes it tough to finesse plus then the tire is in the way. That is why I jack the diff up with the frame still on the jack stands. That way I can use a punch on one side to line the hole up while sticking the bolt in from the other side. I actually don't fight this that bad if I put the bold in last.
You probably could do it opposite and put the bolt in the bracket on the diff last but once you jack it up to where it lines up the gas tank is really in the way.
That is pretty much the toughest part of the rear end. The front end is just about as easy, but getting the passenger spring in and out is kind of my pain in the ass. I actually have a huge prybar and some really big screwdrives I used to get the driver side in and out fairly easily, but on the passenger side, I use a spring compressor. It is the kind that has two one for each side. Even with that it is kind of tough. I know some people here are kind of afraid of those and pretty much unbolt the front end. I found it easier to not unbolt the whole front end and use a spring compressor to get them in and out. I have had pretty good luck with it, and I have done my Jeep several times, and my Wifes Jeep just today. I just keep them lubed up before I put them away. Seriously they are cheap harbor freight specials, I think I paid 18 bucks for them and probably got 20 percent off of that, but they have been really great. I don't use air on them I only use hand tools so it is quite slow, but also may be why I am not having issues with the tool.
So regardless if you do it my way or the others way, That is really the hardest part of the job for me. Rear track bar bolt and front pass side spring. Other than that it is a cake walk. Also the things I said are the hardest for me, is not really that hard. Just wanted to set some expectations.
just for a frame of reference, i can do the rear with hand tools in an hour and the fronts in about two hours with hand tools. If you have access to air you can probably do it faster. Although figure a day if it is your first time.
Good luck keep us posted and post pictures.
OP
I just completed replacement of OME LD springs with OME HD springs. I followed the OME recommendation of installing the front A spring on the driver's side and the rear A spring on the passenger's side. I gained 1.75 inch average ride height in the rear and 1 inch average in the front. My left rear is 1/4 inch higher than the right rear and my right front is 1/4 inch higher than the left front. The Jeep seems to be level front to back. Previously I had 3/4 inch spacers on the rear to level the vehicle. I took those out and did not use OME trim packers on either the front or the rear.
Now, for ride quality. I know there are strongly held beliefs on this subject so don't shoot the messenger, I am just reporting what I have found. Prior to changing the springs I took two neighbors out for rides individually. Then after changing the springs and without telling them what I had done, I took them out a second time. Same road, same speed, same tire pressure, same shocks (OME Nitrocharger Sports), same fuel tank level, same everything. Both reported they thought the ride was harsher. I did too, but my vote doesn't count because I knew I had installed the HD springs. I had first put on the rear springs and driven it that way and I could tell the difference. Then I put on the front springs and I didn't notice any additional change. This would make sense to me because the rear HD springs have a higher spring constant, while the front springs have the same spring constant as the LD springs but are just longer.
Next, I think I will switch to Rancho shocks to try to improve the ride quality.
Now, for ride quality. I know there are strongly held beliefs on this subject so don't shoot the messenger, I am just reporting what I have found. Prior to changing the springs I took two neighbors out for rides individually. Then after changing the springs and without telling them what I had done, I took them out a second time. Same road, same speed, same tire pressure, same shocks (OME Nitrocharger Sports), same fuel tank level, same everything. Both reported they thought the ride was harsher. I did too, but my vote doesn't count because I knew I had installed the HD springs. I had first put on the rear springs and driven it that way and I could tell the difference. Then I put on the front springs and I didn't notice any additional change. This would make sense to me because the rear HD springs have a higher spring constant, while the front springs have the same spring constant as the LD springs but are just longer.
Next, I think I will switch to Rancho shocks to try to improve the ride quality.
Thanks for the extensive reply I appreciate it enormously, especially from some who has installed a few sets!
Sorry for hijacking the thread a little @TurboTJ
Heres the set I picked up I'll post some photos in my build thread when I get time to install https://wranglertjforum.com/threads/australian-black-beach-eagle.14537/#post-234993. Moving house is a pta.
And after a little clean
Not sure on the condition of the shocks they rebound pretty slow but there is some decent resistance pushing them. Not too worried as my plan is to replace with rancho shocks.
I have messed with light duty and heavy duty both (OME) and didn't really feel any difference. To me the only difference was right height. I believe the spring rate isn't really that difference between the two. The heavy duties might give you more lift if you have less weight as in no back seat or hard top.
Most people here will tell you that it is all about the shocks. You shouldn't feel any differences in springs. Now you if your old springs had some crazy spring rate then you might feel a slight difference.
Try this without know what tire size you have try lowering the pressure to 26psi and drive that same route and see if there is any difference.
Also I just did the OME on my wifes today and I put daystar 3/4 inch spacers up front and kept the stock spacers that came on the Jeep and I did the A and B exactly like you and it is almost dead level all 4 corners. Maybe at most a 1/4 inch difference.
We drove wifees around the block and it rides like a car. She is pretty impressed with it. Sorry to hear yours didn't go as well, but try lowering tire pressures and see if it helps.
Looks great! Those look like an old school set, but if they are still good they should work good for you. The new shocks have black plastic boot types on them now, and are called sports. They are super expensive, but a really good shock. I don't really have any experience with the older stuff, but I don't think you get a good rep if your old stuff sucks. So I am betting you are going to come out OK here. Good luck and waiting patiently for the pictures haha.
OP
Yeah I contemplated and contemplated and decided to go with the HD' on the wifes because she has a hard top and still has the back seat. Her daily driver is a two seater mini roadster, so if family comes to visit we will most likely be in my GMC or her Jeep. Plus she treats the Jeep like a 3/4 ton truck and loads it down, so I decided the HD's would be better. I also didn't use any OME spacers, but did use a daystar 3/4 inch up front which made it dead level so far, so if anything settles I may need to add a small spacer somewhere at some point.
I will post pictures when I am completely done, but I am also going to upgrade the steering to th zj stuff, and I also ditched the transfer case drop, so I still need to get some new bolts for the crossmember. I am also waiting for some spicer u-joints for the rear driveline. Weirdly I don't need a transfer case drop -maybe because of the hard top.
I did drive it around the block, and it rides great and it is so much better with the stick shifters back in the stock position.
Anyway it rides great, and it shifts good, just a few loose ends to tie up. It may get my old Duratracs on it too, and a detail.
Yeah, I think you have an amazing butt if you can tell the difference between 140 and 160 spring rate. Sounds like you did everything right. It is weird that it is riding bad for you, I wish you were close so we could compare jeeps. Maybe drive it around a little more and give the shocks and springs some time to settle. I not sure what shocks you were running, but I am running OME nitro sports on the wifes and they were good through the get go, but on my Jeep I am running the 5000x and it took some time for them to settle down a bit. Maybe drive it around a couple days and see if it gets any better.
Not sure what the problem is, but most people swear their TJ rides much better than stock with the OME. That was the case for me too, but I know that all Tj's are different and a lot of the reason is the set up. When I had the same OME lift on my TJ, I had wll over 2 inches of rake. To level it out I ran a 1 3/4 spacer on top of the lift in front. (still had a slight rake)
On my wifes Jeep, I installed the actual OME lift, because I have a currie 4" now, and setting it up hers, I did just the HD rear spring with no spacers same as mine, but only did a 3/4 daystar spacer on HD fronts and it was dead level. I mean if ether side sags I will probably add a OME spacer at some point. Honestly I think hers may ride a little better than mine did, but hers is slightly newer and a lot less miles. Mine is a 98 hers is a 2000.
Mine has no back seat no hard top, and not even a framed top, but I do have a Dirtworx rear bumper with swing out tire carrier, but that setup is pretty light. Hers has a hard top, and a back seat.
So can tell Tjs are all different so it is hard to tell what you are going to get till you get done and try it.
I know you said you didn't use any OME spacers, but you kept the factory spacers correct?
I would agree with this. I have the HD’s and rode in a Jeep with the LD’s and there was a difference - both light weight rigs. I believe it might be how the stiff Nitrocharger Sport reacts to a stiff spring and light Jeep. I’m also hoping the softer riding Rancho 5000x will help and I’m installing this week.