Great Lakes 4x4. The largest offroad forum in the Midwest banner

Project Midlife Crisis

67K views 378 replies 27 participants last post by  xj4life  
#1 ·
The planning stages of this build started about five or six years ago, but four years ago while going through a divorce I decided it was time to stop waiting and to pursue my dream. Couldn't think of a good name for this build, but since I'm turning 42 this year Project Midlife Crisis seems fitting :sonicjay: Its going to be used for all types off wheeling but with a focus on rock crawling.

I had a couple goals in mind with this build when I started...1) Learn a lot. This is my first buggy build. I knew I had a lot to learn and it may not work perfect when I'm done but I didn't want that to stop me. Only one way to learn and that's by doing things and making mistakes. 2) Budget...I'm a single Dad with two young kids so have to keep cost as low as possible. 3) Jeep based powertrain. Why? Well Jeeps are what I know, they are what I love, and being that my time and money were limited I decided to not pursue the LS route. 4) Design/fabricate as much of this build as I can. I am a mechanical design engineer with access to fabrication equipment and I love metal fabrication. So I knew I'd enjoy building this just as much as driving when I'm done.

So four year ago I picked up donor 199? XJ, some DOM tubing, and got started. I spent some time rough modeling the build in CAD before cutting any steel. I'm only working out of my two car garage at home and I don't have easy access to a bender so I designed the chassis with as few bends as possible. Also tried to make the design simple enough for me to assemble. I tacked together the base cradle on a layout table at work but everything else I've done at home. I've had to make a few adjustments to my original design but I have to say I'm pretty happy with how well its gone so far. I have a lot of work left to do (and money to spend :sonicjay:) but figured it was time to start a build thread. I've got questions on a few things that might get answered and it might help keep me motivated to finish this thing some day. I only get a few hours a week to work on this project so over the last four years I've been chipping away at it when I my schedule and cash flow allow.

Build Specs/Plans:

Chassis:
2 seater (might see if I can fit a small bench seat in back for my kids)
113" wheelbase
21" belly
Main chassis is 1.75"x0.120 DOM, frame rails are 2"x4"x3/16" wall rectangular tubing, sliders are 1-7/8"x1/4" wall DOM

Powertrain:
Jeep 4.0...I was told its had some internal work and computer upgrades but have no way to confirm that. I was able to drive the donor Jeep before gutting it and it did seem to have more power than a stock 4.0.
AW4 with RAD manual shifter
Flipped D300 with 4:1

Front Axle:
Ford BJ Dana HP60 housing (not sure the exact year, 92-99 range I believe) w/ 4.10 gears (for now)
Barnes4x4 HD diff cover
Full hydro steering
My own truss and link mounts
Couple unknowns at this time. One, which locker I'm going to use. Second, what D60 outers I'm going to use. More on that below.

Rear Axle:
14 bolt w/ 4.10 gears (for now)
Probably a Detroit locker
Barnes4x4 pinion guard with the truss tie in, disk brake brackets, and HD diff cover
My own truss and link mounts

Suspension:
Double triangulated 4-link front and rear
Lowers are going to be 7075 aluminum and uppers are going to be 1.75x0.120 wall DOM
1-1/4" heims all the way around
Current plan is 16" travel coilovers on all four corners with 5" up travel, and 10" of droop (11" of droop might cause issues, we'll see)

Tires/Wheels:
Chassis and suspension are set up to run 40"x13.50" tires, not sure which ones yet.

Interior:
Corbeau suspension seats with 5pt harness
Basic gauges
???
 
#151 ·
No new pictures to post, but I've been putting in a lot of hours late at night working on getting the wiring finished up. Starting to have a love-hate relationship with wiring. It fairly easy and my OCD is having a good time making it all tidy...but damn I am ready to be done with it and onto something different.
 
#152 ·
Still just plugging away at wiring. I'm down to lighting circuits so I'm getting there. Once every wire is run then I'll worry about taping, looming, fastening things in place, etc. Also got center concole layout finalized and trans/tcase shifters installed. I have the majority of my hydro steering parts in now so need to figure out how/where that's all going to go. Still lots to do but starting to feel like I can see some glimmer of light from the end of the tunnel.



Days and days worth of wiring. Not as tidy as I envisioned but still happy with it so far.

Image


AW4 and D300 shifters are in.
Image


Trans cooler and battery in there places
Image

Image
 
#155 ·
I agree! Thanks for the motivation :)

You need to look at venting that D300 while it's still easy to do. Also, make provisions to capture the oil leaking around the shift rails with it flipped. It's going to leak.(new rails, double seals.....yeah, it still leaks.) It'll leak much worse if it's not vented well.
Noted. Everything is going to come out of the chassis at some point before it leaves the driveway....engine needs a rebuild, trans needs seals, and I was going to see what the tcase needed. Just want to get EVERYTHING roughed in before I start pulling things out.
 
#160 ·
Got some of the hydro steering components mounted. Tried to consider hose routing as I went.

Cooler tucked next to the radiator. Hopefully gets enough air flow.
Image

Image

Image



Orbital on the same bracket as the brakes. Fabbing up a steering column soon. Filter is just in front of the master cylinder.
Image

Image

Image

Image



Decided the only way to mount the reservoir high was to run it out above the hood. Not the cleanest look but I'm ok with it.
Image
 
#166 ·
Decided the only way to mount the reservoir high was to run it out above the hood. Not the cleanest look but I'm ok with it.
View attachment 280879

KillerB (OG's know) asked me exactly why I had mounted the reservoir so high and that got me to thinking. It was because the older, log-style intake manifold was in the way. Well I forgot I had recently picked up a newer style intake for free so last night started cutting out the brackets for the reservoir and working on swapping intakes.
 
#161 ·
I wasnt sure how to properly size the hoses for the hydro steering so I decided to contact Eric @ Radial Dynamics (where I ordered all the major steering components) and he gave me good direction on what size hoses to use. I'm going to post this here for future reference.

You are running a 6 GPM pump so for this, I recommend a -12 low pressure feed hose from the reservoir to pump, -8 high pressure hose from pump to orbital, - 6 high pressure hoses from orbital to ram, and for the return from orbital back to reservoir (including filter/cooler) you should use low pressure -8 minimum but -10 recommended.

Just for reference, hose sizing goes not by the ports that you are connecting but rather by flow velocity. 6 GPM is a constant through the main circuit but by hydraulic rules of thumb, the feed should be limited to around 4 FPS (ft/sec) flow velocity, high pressure lines 15-25 FPS, and return lines 10 FPS. By evaluating the flow in GPM and the ID of hoses, the above recommended hoses fit those general rules for velocity.
 
#162 ·
Would like to try and get coil-overs on order sooner than later so I'm trying to figure out how I can come up with the sprung weight to get the correct springs. I don't have easy access to race scales so I was thinking about getting a crane scale like this below. Use my engine hoist and lift from the middle of the chassis front and rear to get front and rear weights. Should get me decent numbers right? I'm assuming it wont weigh over 2k pounds front or rear. Not everything is on the buggy yet so I'll have to factor that into what I think final weights would be.

https://www.amazon.com/dp/B088BL3DF...088BL3DF5/?coliid=I13UTFP3EL3P4Q&colid=383P44OQ4BZI2&psc=1&ref_=lv_ov_lig_dp_it
 
#163 ·
I think you should be able to get some good info using that. Should help you get sprung vs un-sprung weights also.

Please keep us posted on who you choose to order from etc.. I really wanna upgrade my suspension at some point. Accutune seems kinda cool because it sounds like they spend a fair amount of time trying to help you get good valving and set up out of the box.
 
#164 ·
My plan is to order from Accutune for those same reasons. Havent really decided yet exactly what I'm going to get other than Fox coil-overs (probably remote resi) and 14" travel. I'll see what they recommend. Not sure if I'll go 2" or 2.5" and considering the DSC adjusters so I can make adjustments (rock crawling vs dunes).
 
#165 ·
I have 3.0 springs for 2.5 coilovers you can borrow to set it down on if you want to save money not buying the scale. You won't be able to get your final springs ordered until you have it all complete so figure out the shocks, order them, and do springs once it's all wrapped up. I'm sure you can find someone with 2.5" springs laying around to borrow at that time too. Or you can take a look at similar buggies and use the weights they run. If you plan on 2" of preload, you won't miss your guess by more than you can take up with preload anyway. My $.02
 
#168 ·
KillerB was a good dood!

whoa! That pressure valve seems like a neat little gizmo. I may have to add that since I have already had fluid leak out the hose.

I bought my Kings from FilthyMotorSports and they were always helpful. They have a (as do most anyone these days) spring exchange program so you can order springs you think you need, then when you get all the weight settled and you need new springs, you exchange them.

If you do the scale method you need to take the weight of the axles/wheels out.
 
#169 · (Edited)
KillerB was a good dood!

whoa! That pressure valve seems like a neat little gizmo. I may have to add that since I have already had fluid leak out the hose.

I bought my Kings from FilthyMotorSports and they were always helpful. They have a (as do most anyone these days) spring exchange program so you can order springs you think you need, then when you get all the weight settled and you need new springs, you exchange them.

If you do the scale method you need to take the weight of the axles/wheels out.
Yes he was/is 😁

From what I know that pressure valve is supposed to prevent leaks and keep a small amount of pressure to reduce cavitation.

Sunday I did end up scaling everything as it sits is right now (chassis as is sits, front axle, rear axle, winch, wheels, and tires) and the total weight was just north of 3100 lbs. Seemed light to me so I need to find something of known weight and make sure the scale is accurate. Not sure what the unsprung weight (minus axles, wheels, tires) was but I have it all written down at home. I still planning on ordering from Accutune so I want to at least get the number close. Once I verify the scale is correct/close I might sit down and see if I can figure what the final weight might be. Most everything is on the buggy but still a few more items to add.
 
#171 ·
ha ha, for sure IS a good dood.

I read up on the valve after seeing you post it. I ordered it from Summit last night...will be here at about 1:30 today.

If you use the springs for weight, make sure you charge the coilovers up. I did not and it messed with my numbers a bit. I also added a lot of things after, but it helped me out in the long run. Started at 7" shaft showing and now I'm at 6"...perfect!

what is the lead time on coilovers these days? I Had to wait around 3 months at the very beginning of Covid.
 
#172 ·
ha ha, for sure IS a good dood.

I read up on the valve after seeing you post it. I ordered it from Summit last night...will be here at about 1:30 today.

If you use the springs for weight, make sure you charge the coilovers up. I did not and it messed with my numbers a bit. I also added a lot of things after, but it helped me out in the long run. Started at 7" shaft showing and now I'm at 6"...perfect!

what is the lead time on coilovers these days? I Had to wait around 3 months at the very beginning of Covid.
What are you running for travel numbers? I'm going with 14" travel CO's setup with 5"-6" of up travel.

No idea what lead times are these days but I'm sure its longer than I'd like :ROFLMAO: I'd really like to have this thing ready for a shakedown run this summer, which is why I'm trying to get it to the point where I can get them on order soon.