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Discussion Starter #1
Since installing my Smittybilt SRC front bumper, Hella 500 lights and Smittybilt XRC8 winch, the front of the Jeep is practically dragging on the ground. Kinda looks like a Funny Car. Since I don't want to lift it (I have a hard enough time getting in now.........and the wife needs a step stool), what are my options for regaining lost front end height due to excessive weight? If the answer is some sort of spacer lift for the front only, do I have to screw around with things like track bar relocation brackets, longer shocks, different bump stops, etc.? Any advice would be appreciated. :D BTW, I'm not necessarily looking for the cheapest way out..........I want whatever I do to work pretty much like stock.
 

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Measure the difference in height from rear to front and then you know how much of a coil spacer lift you will need to balance it out. OR look into HD Springs for the front. They are built to resist the extra weight your bumper and winch added to the front.

Get in touch with GOAT from Poly performance on here... He could help you get what you need... they are awesome!
 

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you probably need a .5" to .75" spacer depending on how far you sagged. If you are just trying to return it to stock heighth you will not need to make any changes to the track bar. If you are running stock tires you do not need to get extended bumpstops unless you are getting rubbing when flexing. Same with the shocks

Basically, retunrning the height to stock will actually CORRECT those issues. It is when you go beyond stock height or add larger tires that changes will need to be made

If you use spacers the ride will be similar to stock. If you ahve the money, stiffer front springs will really improve the ride and help get rid of that nose dive when braking. IMO, the Jeep handles better with stiffer front springs if you are running a steel bumper and winch. Only problem is, aftermarket springs are normally longer then what you are looking for.

Also, what model do you have? It is possible the Rubicon springs may be a little stiffer then the x springs if that is what you have now
 

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Discussion Starter #4
I've got an Unlimited X. Currently, I'm running Rubi wheels and tires. All I'm really looking to do is get back to the stock ride height (or maybe just level the front with the back) without creating other problems that will cause me to spend more money (I'm sleeping on the couch already). :D It seems to me that there might be some advantage to springs as opposed to spacers, since the dealer wouldn't be able to easily tell that anything was done to the front suspension. Comments?
 

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Well....the stock Jeep was likely sitting with a rake to begin with. At least an inch lower in the front. You probably reduced another inch in the front with all that weight. I'd try and find a two inch spring with a heavier spring rate to handle the extra weight. You should be back up to stock or a little higher.
 

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Rubicon express has some 2.5 inch springs I believe but if you get the ones for the 2dr then it will be about a 1-1.5 inch spring. Should work out perfect for you.
 

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If you want a cheaper route then get some used rubicon TJ front springs and a .75 spacer should level you back out. The TJ spring has a slightly higher spring rate and .5 inches of lift plus the spacer.
 

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Discussion Starter #9
Next question............would the front end sag that I'm experiencing since installing the bumper and winch, cause a mild case of bump steer? It either feels like bump steer or a lack of shock dampening, I can't quite tell which. As always, any input is appreciated. :D
 

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cgsweet had a full rubi suspension avaiable but I don't think he's a member here. He has the rubi spring which are stiffer than the stock unlimited spring. On another note when the bumper was on my jeep I didn't really have any extra rake in the front.
 
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Next question............would the front end sag that I'm experiencing since installing the bumper and winch, cause a mild case of bump steer? It either feels like bump steer or a lack of shock dampening, I can't quite tell which. As always, any input is appreciated. :D
With bump steer, the vehicle will veer to one side or the other when you go over a bump - as if you had actually steered it that way. Lack of damping will generally be felt as the vehicle bouncing up and down several times after you go over a bump. Lack of damping by itself shouldn't cause the vehicle to steer left or right.
 

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Discussion Starter #12
cgsweet had a full rubi suspension avaiable but I don't think he's a member here. He has the rubi spring which are stiffer than the stock unlimited spring. On another note when the bumper was on my jeep I didn't really have any extra rake in the front.
Tweet's Jeep is unfortunately, a two-door, so I don't think I would gain anything. I lost a little better than one inch of front end height by installing the winch and bumper.
 

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Discussion Starter #13
With bump steer, the vehicle will veer to one side or the other when you go over a bump - as if you had actually steered it that way. Lack of damping will generally be felt as the vehicle bouncing up and down several times after you go over a bump. Lack of damping by itself shouldn't cause the vehicle to steer left or right.
That's the thing, I seem to be getting a little bit of both. I have raced both motorcycles (professionally) and cars and I thought I knew a little about suspension setup, but this one has me kind of baffled. Could be that I need a short spacer lift in the front and new shocks. :bawling:
 

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Next question............would the front end sag that I'm experiencing since installing the bumper and winch, cause a mild case of bump steer? It either feels like bump steer or a lack of shock dampening, I can't quite tell which. As always, any input is appreciated. :D
When you say "lack of shock dampening", are you talking about the steering stabilizer or the actual shocks?

The sag in your front could cause problems like you're experiencing. The track bar and drag link should be pretty darn close to parallel at factory height. The change in that geometry from adding weight could be causing your problem. A 1" spacer could fix it.
 

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Discussion Starter #15
When you say "lack of shock dampening", are you talking about the steering stabilizer or the actual shocks?

The sag in your front could cause problems like you're experiencing. The track bar and drag link should be pretty darn close to parallel at factory height. The change in that geometry from adding weight could be causing your problem. A 1" spacer could fix it.
Both......the steering stabilizer is leaking and will be replaced shortly, but it also seems to me that the stock shocks aren't capable of dealing well with the added weight. On a racing motorcycle, I would increase the viscosity of the fork oil if I had added weight to the bike (or to myself :beer::beer::beer:) and this type of problem would be solved. Without the option to do the same thing on the Jeep, I'm thinking new shocks might be in order.

As far as the bump steer thing goes, will weight sag cause the track bar and drag link to get out of parallel? And by parallel, I assume that you mean in a static position (parked). Yes?
 
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Both......the steering stabilizer is leaking and will be replaced shortly, but it also seems to me that the stock shocks aren't capable of dealing well with the added weight. On a racing motorcycle, I would increase the viscosity of the fork oil if I had added weight to the bike (or to myself :beer::beer::beer:) and this type of problem would be solved. Without the option to do the same thing on the Jeep, I'm thinking new shocks might be in order.

As far as the bump steer thing goes, will weight sag cause the track bar and drag link to get out of parallel? And by parallel, I assume that you mean in a static position (parked). Yes?
First visualize the track bar connected to the chassis at one end and to the axle at the other end. Then, as the axle moves up and down, the end of the track bar that's attached to the axle will swing in a large arc. That means that the axle itself has to move slightly to the left or right (following the arc) as the axle moves through its full range of vertical motion.

The drag link is also attached to the chassis at one end (well, sorta through the Pitman arm and steering box) and to the steering knuckle at the other. As the axle and knuckle move up and down, they force the knuckle end of the drag link to move up and down, too, which means it also swings in an arc and the knuckle end moves slightly left or right. This motion trys to pull or push the steering knuckle left or right. If it does, that's the same as you turning the steering wheel, it causes the vehicle to veer one way or the other and it's called bump steer.

However, if the arc that the drag link swings on is exactly the same as the arc the track bar makes, then the two effects cancel eachother out - the axle moves, say, left due to the track bar arc, but the drag link swings on the exact same arc, moving left just the same amount, so the steering knuckle remains straight - no steering input, no bump steer.

If the drag link and the track bar are the same length and are parallel at any point, they will remain parallel through their entire range of motion - a basic property of a parallelogram. So, if they were equal and parallel at stock ride height, they should be parallel even with sag.

Unfortunately, for our vehicles, the drag link is quite a bit longer than the track bar (about 41" vs 33") so even if they are parallel at ride height, they won't be at extreme compression or droop.

My guess is that on a stock vehicle, both the track bar and drag link are fairly close to horizontal which means that they are operating on the least sensitive part of the arc. Lifting (or sagging) makes both operate off horizontal and in a more sensitive part of the arc (more lateral movement per inch of vertical travel). So, your situation could introduce some bump steer, but I would doubt that you'd see very much with the numbers you are talking about.

Castor (lack of) and toe out can also make a vehicle somewhat "darty" going over bumps. If you've done anything that would have modified these, you might want to have them checked.

Sorry for the long discussion, hope that you find the problem. By the way, mine drives something like a pig on the street and was prone to wander a lot even when bone stock - you may end up having to live with some quirks.
 

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Discussion Starter #17
Thanks for the detailed info. Maybe this will help me sort out the problem. FWIW, mine tracked like a freight train when it was stock. Now with the 32s, bumper and winch, "darty" would be a very good description. Not undriveable, just annoying. I put a couple of bottle jacks under the front crossmember and raised things up an inch and the draglink and trackbar are parallel as far as the I can see. I think I'm going to start by installing a new steering damper and a 1" spacer lift (front only), if I can find one. I'll hold off on new shocks until I see what the results are. Thanks again for the help. :D:beer:
 

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Have you thought about replacing the springs only with the OME HD springs? I believe that without the OME shocks to go with this setup, you wil get a nominal 1.5" - 2" of lift before taking into account the weight of your add ons.

P.S. You of all people...what did I say about stupid newby questions?:thefinger::thefinger::thefinger:
 

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Discussion Starter #20
Have you thought about replacing the springs only with the OME HD springs? I believe that without the OME shocks to go with this setup, you wil get a nominal 1.5" - 2" of lift before taking into account the weight of your add ons.

P.S. You of all people...what did I say about stupid newby questions?:thefinger::thefinger::thefinger:
I am a "Stupid Newb", and proud of it. :thefinger: Lack of knowledge of any given subject has never detered me from diving right in. Hell, you of all people, a helicopter pilot, should understand that. If you had had ANY idea what made those things fly before you climbed in one the first time, you'd have become a tanker like the Gunny. :D

Oh yeah, I have thought about springs vs. the spacer lift, but I can't get any definitive answers on the amount of lift I will get given the weight of what I have on the front of the Jeep. What I really don't want is to lift the front beyond original stock ride height.
 
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