Lacky is poking at the SAS idea...

[Lacky01]

According to this thread, I am working on converting my truck to 4WD.
I'm for sure doing "half" of the swap first. this includes tranny, transfer case, and rear driveshaft. that way I at least have low gear and just need to decide what I want for the front suspension.

I am 90% sure that I'm just going to put a stock differential in the front and be done with it. It will be cheaper and easier, and I'll be able to have my truck down for less time. It is my DD afterall.

However, I'm the kind of guy that doesn't like doing work twice. If I have in my mind that I'd like to do an SAS eventually, then I might as well do that first right? I don't want to lift it more than 2 or 3 inches. I also want to run 32x11.50 tires. I want this vehicle to behave very well on the street, and also very well offroad. the typical places I'll offroad would be fire and logging trails and stuff like that. I understand that the stock IFS can handle that stuff just fine, which is why I'll probably end up just doing that. but its not NEARLY as cool!!

My concept involves running a D30. I'm not sure what vehicle it would be out of, but I've read that I can keep the 5x4.25 lug pattern, stock width (or close to), and even keep ABS (I imagine that would help its road manners, a don't know if ABS helps offroad). Since I don't want to lift it high, I expect I will have only 4ish inches of up travel. as long as I can get the same up travel as the IFS I'll be happy. where I think the solid axle is going to shine over the IFS is in down travel. could I expect 8-10 inches of droop? I've been trying to learn as much as I can about suspensions, and I think a 3 link would be my best bet?

this is literally ALL new to me. I know its gonna cost money I dont have and take time I dont have. and in order to do it well, and do it semi-cheap it will take LOTS of planning and patiently sourcing out the correct parts. Am I headed in the right direction?

 

[gmanpaint]

I will bump this for you with a condensed reply.

1) If you want to do it right the 1st time, go with a D44 or bigger, and gear for bigger tires than you plan on running. What about a locker? Which type is more suitable for you?

2) Do you want leaf springs or coils?

3) If this is your DD, you need another vehicle to use while this is being done. Plan on it being down for weeks (if not months) at a time for such a conversion.

4) If it were me, I would keep the sport as it is, and find another rig that is already 4x4 equipped, such as a solid 1st gen with no crumple zones in the frame, and no monster cross member to cut off and grind down. This would cost as much as it would to convert to 4wd, plus, you will have a DD with the sport.

5) Expect more than 2-3" of lift. The SOA will net 5.5" alone. Add tires to that, and you can be looking at 9-10" of lift.

6) Depending on the set up you choose, you can get over 20" of droop easy.

7) A lot bigger undertaking than it seems. Choosing things like heims or bushings is enough to make a person frustrated with choices...lol

 

[Lacky01]

I will bump this for you with a condensed reply.

1) If you want to do it right the 1st time, go with a D44 or bigger, and gear for bigger tires than you plan on running. What about a locker? Which type is more suitable for you?

when you say plan for bigger tires and such, are you assuming I will want to go bigger? I really don't want to go bigger than 32s. I look at any explorer with 33s or bigger and think: "that looks cool, but thats bigger/taller than I would want." also, if I went with a D44, wouldn't I be limited to 5x5.5 wheels? then I would have to change the rear end too. and I'd like to use the 5x4.5 wheels I just bought. besides, since I would stay with the 32s isn't the D30 strong enough for that size tire? I don't think I would run a front locker either. if I did, It would be an air locker and I could add it later.

2) Do you want leaf springs or coils?

I want to run coils. I'd really like to run coilovers, but since theres no other SASs at this proposed ride height, I'm worried I would have to guess on what size to run and I imagine that could get spendy in a hurry.

3) If this is your DD, you need another vehicle to use while this is being done. Plan on it being down for weeks (if not months) at a time for such a conversion.

I have another vehicle I can drive while its down. I also have some shop space opening up at my parents place later in the year. I would just have to arrange with him to fill it up.

4) If it were me, I would keep the sport as it is, and find another rig that is already 4x4 equipped, such as a solid 1st gen with no crumple zones in the frame, and no monster cross member to cut off and grind down. This would cost as much as it would to convert to 4wd, plus, you will have a DD with the sport.

I'm a sucker for punishment, like a challenge, and love having a project and learning something new. I've already been through the "just buy a 4x4" discussion with my 4WD conversion thread. this is what I want to do, not what I feel I HAVE to do. I WANT to make it work.

5) Expect more than 2-3" of lift. The SOA will net 5.5" alone. Add tires to that, and you can be looking at 9-10" of lift.

Does it HAVE to be a lot of lift? can't it be designed to run at whatever ride height I want? I understand the engine crossmember is in the way, but that can be cut out. I can easily envision a custom crossmember that sits level with the framerails and unbolts in case I need to get to the oil pan. and I dont want to do an SOA, I would just run some 2" lift springs to match the front height.

6) Depending on the set up you choose, you can get over 20" of droop easy.

would this type of setup be a 3 link? or maybe extended radius arms?

7) A lot bigger undertaking than it seems. Choosing things like heims or bushings is enough to make a person frustrated with choices...lol

I totally get this, but I figure if I can do all my homework and learn all about this. then recruit some experienced help when it comes time to actually doing it, I should be able to pull it off? I will definitely do half of the 4WD conversion first. I will decide at a later date if I want to put in the IFS D35. then as I come up with some definite plans I will slowly start to locate parts and slowly amass everything I need to get this done. my goal: to have this completely designed and planned out before the end of 2011.

 

[CodePoet]

My opinion is that an sas is worth looking into if you're only planning on 32"s.

You don't need a lot of lift. I have 1st gen but I have less than 6"s of lift with my sas and run 35"s. It even fits in my small garage with the roof racks on so it's low

 

[Lacky01]

One thing I'm having a hard time wrapping my mind around is the panhard bar in a three link set up. From what I understand so far is the two main links need to be as long as they can be within the space limitations. The third upper link is responsible for maintaining caster and pinion angle throughout travel. And I get that the panhard bar is responsible for locating the axle latterally, but what confuses me is that the bar swings on a radius like the arms. So when drooped, does this mean the axle won't be in the same spot latterally as when its compressed?

I haven't even begun to look into steering geometry :^P

Can anyone reccomend a book on suspension geometry theory? Or if there's a good source online that would be sweet too. Id like to make sure I understand the mechanics of it before I attempt any plans or designs.

 

[rookieshooter]

Chassis Engineering by Herb Adams. Next you'll be telling everyone about Roll centers, Instantanous centers and Anti squat ha ha
It was the book I turned to when designing my front 4link and rear linked suspension.
Coupled with the info you get on this site, it's a deadly combination ha ha No pun intended.

 

[Lacky01]

sweet thanks! I think learning what I'm doing will be integral to maintaining good road manners. ...and make it more fun

 

[Lacky01]

so, in planning my ultimate explorer, I've read through some threads about hydraulic steering. I think this is something I'd like to do, mainly because it would simplify the steering setup by not having to do a panhard bar and stuff like that. BUT I understand that full hydraulic isn't necessarily safe due to its lack of redundancy. If it fails, I lose control. not good.
so the question: can I use the stock power steering rack on an SAS? It would mount the same to the front of the axle as a full hydraulic. and the steering shaft could be extendable, kinda like a driveshaft right? that way it can keep up with the movement of the axle. this way, I still have power steering, stock steering geometry, and redundancy in case of failure.

comments?

 

[DB_1]

You will need a panhard bar if you run any type of suspension other than a dual triangulated 4-link set-up. Our trucks simply do not have room for this type of set-up. Full hydraulic steering can be expensive depending on the parts you choose. This type of steering is usually reserved for dedicated trail rigs to help turn large tires on locked axles.

You're gonna need to grab a steering box from a first gen or some guys even use Toyota steering box's...check out Section525's build thread for more on this. This is safe, effective and simple, I would not try to rig up your rack and pinion steering.

I've been running 35"-37" tires on the stock steering box for about 10 years now and I haven't had a single problem to date. Eventually i'd like to go with hydraulic assist steering to help turn the tires. Basically it's a single ended ram that works in conjunction with your existing steering to give you that extra turning power when off roading. Since you will only be running 32's, a steering box is all you will ever need.

The only steering geometry you really need to know is keep your panhard and drag link as close to length and angle as possible or you will have bumpsteer problems. That is when the steering wheel wants to jerk out of your hands when you hit bumps in the road.

 

[Lacky01]

thanks for the insight db1

So is the pitman arm the part that connects the steering box to the panhard bar?
And the bar connecting the two steering knuckles is called the tie rod like the ifs correct?

I've been sifting through a bunch of sas threads and it seems high quality heims are the preferred joints on the panhard and tie rod. What is the preferred type of joint for the links in a 3 link setup?

 

[DB_1]

The panhard is considered a suspension link and it keeps your axle located under the truck (side to side). One end is connected to the frame and the other goes to a bracket on the axle tube. Either heims or urethane bushings can be used.

The pitman arm is part of the steering box, then the drag link connects it to the steering knuckle on the axle. Tie rod ends aka TRE's or heims can be used, some people like one over the other.

And yes the link between the two knuckles is the tie rod.

For suspension link ends, it's really a preference thing but there are generally 3 types of joints on the market:

Rod ends aka heims
Cartridge joints aka Johnny Joints
Urethane Bushings

In most scenarios you only need urethane bushings on one end of your links and something with more misalignment or movement on the other end like a heim or cartridge joint.

Cartridge joints have one advantage that they are rebuildable but are limited to around 30* of total misalignment which is plenty for most people. If you need more misalignment you would add another joint at the other end, now you have double the misalignment.

Heim joints have the advantage of a lot more movement when misalignment spacers are used...about 60* in a single joint. If you use misalignment spacers, your bolt size will be reduced. Size of the bolt can vary depending on which size spacers you choose.

 

[Lacky01]

So is the pitman arm the part that connects the steering box to the panhard bar?

I see what I did there lol

thank you for the clarification. I think I'm gettin a handle on the lingo. and a few months ago I would browse the SAS threads and I had NO CLUE what anything was. now I read them and I kinda have a clue

so lets say I had a three link set up. you know, hypothetically. and in this setup, the main links will have a "johnny joint" on one end and a heim on the other end. you know, sportin' the bling. I would put the heim on the axle end and the johnny joint on the frame end. reason being the axle end will have more misalignment or "flex" correct?

I need to order that book

thanks again for holding my hand through this learning process :

 

[DB_1]

We've all been there at one point or another, research is the name of the game

As for the joint selection, you could do it that way and it would be perfectly fine. You really need to have the links mocked up and cycle the suspension from full stuff to full drop and check for binding.

You may find that you only need a johnny joint or heim on one end and just a urethane bushing on the other. That would save you some money over buying all those expensive joints. Don't forget you have to buy tube adapters and jam nuts for all those joints.

I have heims with misalignment spacers on the frame end and urethane bushings on the axle end and i'll never max out the joints. The urethane joints are welded solid to the links and the heims have tube adapters so I have a little adjustability if I need it.

 

[Lacky01]

cool, well this project definitely wont be doable until I'm done with school so I have plenty of time to research and plan. I'm working on building a "working" model in a CAD program. that's also gonna take a while, but it should turn out cool. I'd like to have an accurate stock model which can be changed and manipulated in the program, but we'll see.

 

[Lacky01]

so, I think I need a front D30 HP from an '89-'99 XJ (cherokee) with ABS

I'm not lookin' to buy yet. I just need to research all my options. you know that feeling in your gut when you know you did something wrong and are going to get caught? thats how I feel when I search for info on J##ps

 

[Lacky01]

so in my previous "envisionings" of a three link setup, the panhard bar was always directly over the axle. this caused some major concern in my head, thinking that I would HAVE to have a certain amount of lift in order to allow any clearance between the panhard to frame mount and the diff. however, if the panhard was mounted either forward or aft of the axle it would allow the frame to sit closer to the axle. thus less required lift. correct?

 

[DB_1]

That's probably true in most cases but when it comes down to it, you just gotta put the panhard wherever it will fit.

I have a panhard from BC Bronco's and it has a couple bends in it to clear things and it sits forward of the axle. I think you'll find most Explorer/Ranger SAS's have them forward of the axle.

 

[Lacky01]

cool! I think this project will be more long term than I originally thought : the truck will need to be down for quite a while as I mock stuff up and figure out how stuff will fit together. I'm probably giving myself quite the challenge for a first time SAS, but I want to be happy with the outcome. I'd still like to do the "working model" in the CAD program. I just need to take the time to do it. that should help get my mind further wrapped around it.

one day at a time! I'm almost done with a full length roof rack

then its replace the drivetrain with the 4x4 stuff. I'm not gonna touch the front suspension till the sas. just new tires, transfer case for low gear, and a mini-spool and I should be good to go. I'll beat on that combo and get some much needed driving experience while I finish school.

I still need to order that suspension book...

 

[Lacky01]

How do I know whether I need reverse cut gears in the front end? Is it the direction the front driveshaft turns? If I'm reading threads correctly it seems the jeep front ends will have the reverse cut gears, which is correct for a 1354M. Am I on the right track?

 

[DB_1]

Reverse cut or reverse spiral is the same as high pinion. Everything rotates the same direction in a low or high pinion axle so either style will still work with the T-case.