upgrading suspensions for a noobie

[raser13]

i have a pretty much bone stock 1980 CJ5 . it does have 31 inch tires and a winch. that's all my mods. lol. it has the AMC 258 i6 / 4.2l straight six, T-176 , Dana 300 combo. i just bought a 1982 CJ8 /scrambler. this one is about to become my daily driver/light trail jeep. it will stay mostly stock like the 5 is now. i am changing the motor out to a AMC 304 . i just can't bring myself to tear up such a rarer beast.

that means that the CJ5 can now become a more aggressive toy. i still want to have it be road worthy. but i want to give it a little more ground clearance and flexibility. but i want to make sure that i'm doing it right. i.e. not get to top heavy or thin or get the geometry off for the drivetrain. is there a good place to read up on how to start conversions? do i need to swap out to coil springs compared to leafs? what's the best way to lift? what's that magic point where you really need to start doing all of this? and i need all of this to fit in my budget too. lol

i'm basically wanting to star doing some of the overlanding out west and in colorado. i've just been doing trails here in missouri. like smorr (SMORR – Southern Missouri Off Road Ranch) i'm wanting to get into the little more aggressive trails that a stock jeep just can't quite handle. i'm not wanting to get to where i'm going over boulders.



or go up cliffs like



but i do want to be able to handle things more like this







i know a lot of people that just bought a lot of parts and just slapped them on their jeeps to make them big and bad. they spent a lot of money and don't even know why they needed it. but the jones had it so they had to keep up. i want the know the wheres and whys of things. i don't have the keeping up with the joneses budget. so knowing just what i need for what i want to do, and why i need it, and what else i have to change just because i decided to lift, or add a new axle,ect.

so good books on the subject? websites? anywhere i can absorb the ins and outs of suspension modification? or recommendationson what i might want to do and why, how? any info would be great thanks guys.

 

[Torxhead]

For starters, just what size tire would you like to use? I think that will provide a base for you to build from since the rest of your project has to support them.

 

[raser13]

wasn't planning on going more than 33-35s. don't think that i'll really need to go over that for any reason. can you guys?

 

[Torxhead]

I would say the next plan would be to toughen up the rear diff. Like heavier wall tubes and bracing, along with one piece axles. Gear ratio choice would be a 4:10 to 4:88 and an Overdrive tranny to handle the highway speeds with a lockers like an ARB or Detroit. I have seen a few guys try 35s with the Dana 30 up front with poor results. So at least an axle that uses the Dana Spicer 297x u-joint. So the tires clear the wheels would take at least a 4" spring lift and a 1" body lift. Setting up the driveline angle can be tricky also, like rotating the diffs up and using a constant velocity u-joint. Also front wheel camber has to be set also, which means rotating the steering axis the other way. Going to the 4 to 1 gear set in the Dana 300 really helps slowing things down in the rocks and providing more control. Since you have the narrow track axles your turning axis will be cut down quite a bit unless you compensate for that like going to a wider track axle. Hopefully you will get more responses to help you build what you want as your demands aren't all that much.

 

[Lumpy Grits]

At the angles in those pictures-You had better be look'n into fuel injection, as your first major 'mod'.
LG

 

[raser13]

where or how do you guys learn this stuff? i always see post like yours where you know how all of the gear ratios go together, and that you have to angle the axles and what not. how is that knowledge gained? it's not like they have a class at the local community college where i can pick up a suspension tuning 101 class on the weekends.there has to be some repository of this knowledge it can't be just past on from guy to guy over a campfire. what am i missing?

and yeah, i'm not wanting to go to crazy on the 5 just "toughen it up" a bit. speaking of wich. any recommendations on where to "armor up" i was thinking at least the front diff cover, oil pan, and add a little more to the gas tank.

and lumpy i have fuel injection-ish. electric fuel pump going to a motorcraft 2100.

 

[Lumpy Grits]

I learn'd what little I know from 55+yrs of wrenching, building and break'n stuff.
No carb. will keep your engine run'n at those angles.
LG

 

[raser13]

well then i will have to add a head swap and fuel injection to my list of projects. and my shopping list. thank you.

didn't know that a carb wouldn't cut it on inclines. i've been up some pretty good hills and it's worked. but i didn't stay horizontal very long either. i will definitely defer to knowledge on this one. besides fuel injection is a better system anyhow.

i was hoping to avoid the breaking stuff part.

 

[Lumpy Grits]

When you 'play' like in those first 2 pictures. You will 'pay' as in breaking stuff.
With FI, the engine doesn't know what angle your at. Now, engine oil pickup from the oil-pan is another story.
Build the engine first-Then the rest.
Hav'n been down that road a few times in my life. Kiss your savings account "BI-BYE'.
IMO-You would be better off look'n for a built-rig and keep yours as a DD if you want to wheel like the first 2 pictures.
BTW: What you show in the last 3 pictures of your first post would be very doable, My Jeep see's this kind of stuff all the time. So can yours.
What I'm say'n is this. In those 5 pictures. The first 2 are a different 'world' from the last 3.
LG

 

[raser13]

o.k. i see the confusion. the first two pics were to illustrate what was too far. the last three were to show where i was wanting to be able to go to. i know that the first two would require re-engineering the whole jeep, to the point that it wasn't a jeep anymore, only in skin. lol. the last three were the next level i figured could be achieved with out to much re-engineering or possibility of breakage. i know with any level of offroad play that breakage is a possibility. but i just want to go up that next level from dirt logging roads and creek beds. to larger creek beds and real nature. so a little more armor, and a little more height, and a little more flex. nothing crazy

 

[Lumpy Grits]

Post up the details of your driveline like R&P ratio, tranny, open or LSD diffs and tire size etc.
We are real good at spend'n other folks money.
LG

 

[Peanut Butter]

Like was already mentioned, you need to decide a tire size. 33" takes less mods than 35" and so on. From there you need to beef up your suspension to handed the extra strain the larger tires put on it. Colorado is not a tuff as say Moab. Mostly large rocks and gravel trails. 33" tires would be a good place to start. Look at QuadraTrac and get their catalog. They have good charts for this stuff. Also there are some good books on Amazon that can help. Search Jeep CJ. Search this forum for all the other conversations related to this stuff. There is a lot of information here. SO - Read -Read - Read! Do this before sitting down and writing out a plan. Post that plan with what parts you are thing of. We'll let you know what works and what doesn't. This narrows down your question. Right now it is too broad to completely answer. Talk to the guys from Colorado, look at their rigs and what they did. Maybe they have a build thread. Having lived in Colorado, 4 wheeled many parts while working major Wildland fires, I can tell you that you can have a lot of fun without Hugh modifications. Doesn't mean you will be driving up dry river beds. But you will have fun. This way you'll learn every time you go out what might have worked better. You'll make lots of modifications over a longer time rather than trying to do it all at once. Good luck and have some fun!

 

[Lumpy Grits]

No matter what mods you do-If you can't 'read' the trail, you won't get far.
I have had my Jeep in many of the places PB has spoke about and then some. I've run 33's for almost the life of my Jeep. Doesn't mean I don't have plenty of 'rock-rash' under my Jeep. Don't think 35's would have been that much different.
YMMV, PLEASE do the research and ask away.
LG

 

[Hedgehog]

Just be aware that tires can be deceiving. I run 31's, but sitting next to 32's and even some 33's they are about the same. Jump to 35's and believe me you are in a whole different world. 35's are BIG and HEAVY and WIDE and EXPENSIVE all will need to be dealt with. Where 32's for instance you might net need to do anything with your CJ (except gearing) at all. The brakes can handle the rotating weight, generally the wheel wells are good enough, the suspension is good enough. The jump from 33's to 35's is huge. You mentioned right off the bat that you need coil springs, why? Remember you are on a budget.

First off you have a decent engine to start with. EFI would be nice, but if your carb is up to sniff you are alright for the type of 4 wheelin' you are talking about.

Figure out the tire you really want. My 31's get me where I want to go, 32's or 33's might be what you are looking for. The big tires might be best in mud, on relatively dry ground, except for sand beaches or sand dunes, you simply don't need the big stuff.

Pay attention to your axles and their guts. For me the Dana 30 you have in the front will serve you well enough for your type of off road use. You have an AMC20 in the back. Lots of folks believe it is a problem waiting for an excuse to happen. Yes, you can pile a bunch of money in it. Better axles are #1, different differentials, welded joints and trusses. But those fixes don't address the thin tubes and small bearings in an AMC20 . I got in serious trouble thinking I was helping another poster with the AMC20 and will not go any further.

Differential gearing. You need to work out in your own mind what gearing you will need. Remember regearing is EXPENSIVE unless you do it yourself, even then it's not cheap. Try to get it right the first time.

Armor - I know it's not armor but it sorta is, try to get a winch. Then decent bumpers, tube bumpers look good, but are generally there for looks. Get a good set of bumpers. Nerf bars. I admit to having a set of nerf bars. For me they are fat man steps into the CJ. Rock sliders are the modern way to protect the area between front and rear wheels. Some like those pointy erection looking tube things on the front bumpers. I thing they are little more than a fad, but the good ones will help prevent an end over end roll over. Like bumpers, if you absolutely nave to have an erection get a good one.

With those modifications your CJ will look tough, and beyond that it WILL be tougher.

 

[Lumpy Grits]

When you go to 35's. You need allot of brake to stop'em. The 20 doesn't have that.........
LG

 

[Torxhead]

Rasor, you might want to consider a Jeep Club also, like in your local area. Most of them have their own websites. It is always nice to have someone around to help you fix your Jeep, guide you on a new trail, help to tip you rig back on all fours, and/or call 911.

 

[Lumpy Grits]

110%!
Joined the club I run with in 1978.........
LG

 

[mtnwhlr]

You can do alot with 31" tires but if you want to go bigger go only 1 or 2 sizes then you will look like this

 

[Lumpy Grits]

Don't blame the tires, for choose'n the wrong 'line'.
LG

 

[mtnwhlr]

Don't blame the tires, for choose'n the wrong 'line'.
LG

My point is when you go bigger you start thinking you can do way harder stuff and this is where you can find yourself. My son and some friends is the only thing that kept him on his wheels.