DII Suspension (and related questions) 101

[SCSL]

There are always many questions on DII suspension mods so here's the basic skinny, hopefully save some time searching thru threads.

You can boil down DII suspension into two basic categories, those which require no further modification, and those which will require some extras.

I. The no-further-modification category consistst mainly of OME springs/shocks, OME spring/Bilstein shock combos, or OEM HD spring/Bilstein or OME shock combos. There are other combinations, but these are the most common, and you get the idea. On a DII, any of these combinations WILL allow you to run tires up to size 265/75/16, though there are several other popular sizes run with these suspension combinations. Unlike a DI, you will not have to bend back rear quarterpanel 'flairs'. You will, however, experience rubbing on the front radius arms at full-turn, but nothing dramatic or unmanageable. If you are running stock bumper, you will probably want to cut away the bottom corners of the bumper, where the fog light housing is (or on some models where the plastic is) or you'll get rubbing from the front bumper as well. If you are upgrading suspension to go off-road, you'll want to make this very minor bumper modification anyway. Finally, you'll want to upgrade your steering damper along w/ the suspension (OME seems the most popular & widely used). Many kits come w/ the steering damper, or it can be purchased seperately.

*if you have rear SLS you have 2 options: trick the height sensor to run the SLS higher full-time to match front ride height, or purchase after-market SLS spacers available from several sources. I am partial to tricking the height, as it free - much cheaper depending on your technical skill. Also you'll look & feel funny with fully expanded air bags plus 2" of spacer.

2. The further-modification-necessary category: with these, you'll typically be looking at a "kit" that has been designed to take into consideration the additional requirements of a 3"+ lift. (Kits are available from several after-market companies, including LRO.com's sponsors.) These will generally include extended brake lines, extended ABS lines, longer bump stops, and possibly drive shafts. Some kits include modifications to the shock towers and various suspension brackets. Steering mods (other than dampers), radius arms, etc with lifts in DIIs greater than 2" have not been necessary until you get into 5" + territory. You will need to either remove sway bars, or fit sway bar disconnects, to take advantage of larger suspension lifts. (As I understand, sway bar disconnects available for XJs can be easily adapted to work in Discos.) Otherwise you've wasted your money on suspension that you can't take full advantage of. Furthermore, with the additional height, you'll experience dangerous & sphincter-clinch-inducing body roll off-road (the opposite, however, is true on-road,,,you'll feel pretty weird,,,but you're safer on-road w/out sway bars than off-road with sway bars, assuming a safe, Disco-friendly driving style). Finally, you'll encounter the challenge of what to do w/ the watts linkage, as referenced in a previous thread, which is a problem still being experimented with. You don't typically have to worry about axles until you look at adding tires greater than 33", or adding lockers. You are very unlikely to break an axle with TC/open diffs/CDL unless you take a direct hit from a rock,,and that's what the tires are for. With 3"+ suspension you'll eventually want to add gears, but that opens up a whole nother can of worms with lockers, etc. Bottom line with stock gears and larger tires is this: you will notice less engine braking on steep descents off-road & on-. This will result in using the brake more than you would have to normally off-road. On-road, the problem can be solved by down-shifting more often than you typically would. But off-road you'll have to apply some brake on steep descents where, stock, you could engine drag all the way down. Finally, you'll want to be more respectful than usualy of following distance & brake time/distance. This is not a major issue, but one of adjusted driving style and, as with any modified vehicle, heightened awareness at all times of your capabilities, unique 'feel', and constant vigilance in driving style. So your need for gears is not immediate. That being said, you'll probably have gears on your "to-do"/"to save for" list.

Hope this helps any newer DII owners or future thread-searchers. Thanks to Serg for a great forum.

[SCSL]

I've had several questions lately on lockers & traction control so figured I would add a small bit to this post, since the TC part of the question is directly connected to suspension travel.

Factory TC on DIIs really is a remarkable system. TC gets bagged on a lot, and clearly running lockers front/rear is superior off-road. Problem is, once you lock up you need to start looking at aftermarket axles, which also means wheels (open hub), a compressor (if you go with ARBs), and the whole thing gets very expensive,,may not make sense based on your off-roading activity.

The key with TC is keeping all four wheels on the ground. While this is not always possible, suspension drop helps enormously and allows you to get the full benefit out of your TC. Sway bar removal or disconnects helps you take full advantage of your stock suspension, get more out of your OME suspension, and is practically mandatory with more flexy suspension set-ups. To take full advantage of your TC system, match the suspension modification to the nature of the trails you run (trail rating and terrain: ruts vs rocks vs mud, etc). Naturally, tire selection is critical for taking advantage of TC, lockers, etc. All devices intended to assist forward movement can fail "where the rubber meets the road". Tires, like suspension, should be chosen based on typical trail rating & terrain type, as well as your % of on-road vs. off-road driving.

Another option is the engagement of the centerlocking diff (CDL) that is still there on certain model year DIIs. I don't have the exact data on which DIIs still have CDL lurking on their t-case but I think it runs approx. half way thru model year 2001, and then comes back again for model year 2004. There are 4 options for engaging your lurking CDL:
1. If you know where the bolt on xfer case is that engages the CDL, you can reach up under there & turn it. This may result in ruined shirtsleeves and/or burned arms.
2. You can use a manual device, often a simple fab, that attaches a lever from the t-case outwards to the passenger-side undercarriage that can be manually engaged from outside the vehicle.
3. You can 'jury-rig' a cable set-up to connect to a lever or turn-knob inside the vehicle that engages the CDL.
4. You can get a t-case shifter from a D1 and replace our DII stock shifter, allowing you to engage CDL as one would in a D1 (most expensive option)

Only the most avid wheelers (or the most wealthy) should consider lockers for DIIs, based on the expense and the add'l upgrades required (well, not required, but breaking an axle on the trail really sucks). Another option would be limited slips front & rear, which should not require axle upgrades on DIIs.

[HFsdisco]

On a DII will any oof the systems such as ACE be affected by the use of a 1 or 2" spacer?

[SCSL]

I will be the first to admit I know nothing about ACE and, as such, would be hesitant to answer that. Perhaps someone else on the board has more familiarity with ACE than I do. Sorry

[SCSL]

Bump.
Can anyone help HF w/ lift questions as they relate to ACE ?

[HFsdisco]

Thanks SCSL.... This thread has been very helpful. I am new to all this and I am trying to decide what I want to do to my rig, and a post like that teaches a lot that I had no idea about. Thanks.

BTW....I called the dealership in Cary, NC today about in and the guy I talked to said he didn't know if it would affect anything but that I should call a few other sources. So if anyone knows anything I would appreciate it.

[SCSL]

If you are in NC, your best bet would be to contact the NC Rover club (I had their website at one time but lost it, sorry).

The dealers have varying degrees of off-road knowledge. I found, overall, that they have become less & less helpful of the off-road community over the past several years now that they don't do mods.

The guys in the club will have the best knowledge of not only what works, but what works specific to your local terrain / trails. They will also be able to refer you to an honest indie Rover tech. who may have more info on ACE as it relates to suspension mods. Good luck.

[HFsdisco]

Thanks again. I will try to get a response from the guys at C.R.O.C. I seem to get limited responses though. I did get recommended to a shop that is pretty new to the area, but a guy at the dealership recommended them as well so I guess they know what they are doing.

One other question, Is putting spacers in a one day job or should I go pay a shop to do it?

[SCSL]

Originally Posted by HFsdisco

Is putting spacers in a one day job or should I go pay a shop to do it?

Yes, definately a one day job. An experienced mech or DIY'er can do it in a 1/2 hour. You'll definately want a spring compressor though, if you have aftermarket springs,,,mandatory with 3"+ springs. As with everything, depends on your lvl of experience in this. If you have never done any suspension work, you may want to bring it into a shop & hang around to watch ,,, it beats running into a problem & having an undriveable Rover.

[HFsdisco]

I was wondering with doing just a 1 or 2" spacer is there any other modifications that have to be made? I may sound dumb but I get conflicting answers from different places, so I want to know what to expect...

Thanks

[SCSL]

I just don't know about ACE,,, I wouldn't think it would be a problem but I hate to give advise if I don't know anything abou the system. I think you should call Roversnorth,,,, they'll know.

[HFsdisco]

Originally Posted by SCSL

I just don't know about ACE,,, I wouldn't think it would be a problem but I hate to give advise if I don't know anything abou the system. I think you should call Roversnorth,,,, they'll know.

I found out that neither will affect the ACE, but a buddy told me to find out if there was any modification to the transmition or any linkage something or other....(I forgot)..... sorry if that question is too vague.

Thanks again.

[SCSL]

Originally Posted by HFsdisco

I found out that neither will affect the ACE, but a buddy told me to find out if there was any modification to the transmition or any linkage something or other....(I forgot)..... sorry if that question is too vague.

Thanks again.

He may be thinking of the driveshafts? If so, you'll have no problem at all w/ 1-2" of lift.

[HFsdisco]

Thanks again SCSL... As always I find useful information in your posts. The dealership couldn't even give me that answer. I did go back and read a thread that you posted in about a lift, and I believe that you commented similar to that one. sorry I should have read through them first.

ANother question though, the airbags won't be affected by these either, will they? Sorry to keep on with the questions. The air bags on the suspension, sorry

Thank you, again

[SCSL]

No, there are spacers made specifically for the SLS suspension.