Project Tech Snob

[EndlessMtnFab]

Reading along and seeing how much love you are putting into this Jeep I figured you to be a single guy. Amazing! :thumbup:

I am assuming that when you are done this thing will have all doors and glass... looking much like a "normal" Cherokee to the uninitiated? I don't understand guys that put a similar amount of effort into their rig just to crown it a trailer queen. I'm looking forward to seeing it road- and trail-ready... I doubt you will ever consider it "finished".

At this point ... neither of us have much choice. Stupid thing needs to be done so I can resume driving it. Not a labor of love anymore. Just a chore now.


All glass and doors are being retained. I intend to use this as a daily driver. Will use it for commuting, towing, wheeling, etc.



No vehicle is ever finished ... but I'm going to make this one as close as I can so I can get on to other things in my life.

 

[EndlessMtnFab]

Why have you decided to go with a tie OEM style tie rod set up instead of a heim joint style? What are the disadvantages of the heim style? Just wondering cause on my mild build, I have been looking at the IRO steering setup, and it has heim joints. If they rattle or wear out fast, I would just go with their heavy duty tie rod, and keep every thing else stock.

I explained in a post a few pages ago ... there are several reasons.


1) Heims are illegal in PA (and some other states too)


2) Heims have the *potential* to wear faster on a DD vehicle (road salt, water, grit, etc etc)


3) Not immediately available if you break or damage something. The Chevy TRE's can be found in just about any parts store. The one TRE is modified ... so I will keep a cheap spare on me. The rest I can get anywhere.



It's just a matter of preference. I am not saying heim joints are junk or that they suck. I would just prefer to keep "wear & tear" items easily replace-able. Everything is a compromise. And the roll issue is one of those.

 

[jamiemac]

I explained in a post a few pages ago ... there are several reasons.


1) Heims are illegal in PA (and some other states too)


2) Heims have the *potential* to wear faster on a DD vehicle (road salt, water, grit, etc etc)


3) Not immediately available if you break or damage something. The Chevy TRE's can be found in just about any parts store. The one TRE is modified ... so I will keep a cheap spare on me. The rest I can get anywhere.



It's just a matter of preference. I am not saying heim joints are junk or that they suck. I would just prefer to keep "wear & tear" items easily replace-able. Everything is a compromise. And the roll issue is one of those.

Thanks for that. This is the kind of info that helps. I think I'm going to reconsider going with the Heims, and either go with the IRO heavy duty tie rod or a V8 ZJ tie rod. Thanks again. I probably don't need anything that heavy duty for 31 or 33 inchers anyways. I'm a very careful and slow crawler, and only rock crawl when I have to, to get to a campsite or area of interest.

 

[MNJeeps]

You sir do not mess around.

Loving the build.

 

[DeftwillP]

You're doing it better than Jeep did.

 

[EndlessMtnFab]

More crazy projects !

More tabs !

And more brackets

Why in God's creation am I digging any deeper? :shocked:

 

[EndlessMtnFab]

Time for a quick refresher course so that everyone can follow along.



One definition have been slightly changed so they are more appropriate for the situation at hand.


Anti Squat .... The ability of your suspension to react to throttle input. The rear of the chassis will either "squat" down or rise up/forward depending on the ratio you choose and your desired characteristics for the wheeling you do.


Instant Center .... The imaginary point where the LCA and UCA meet way out in the distance (as viewed from the side). It can also be the imaginary point where angled upper or lower control arms meet in the distance (as viewed from above or below)


Roll Axis Angle .... How the body pitches/yaws/leans around the imaginary centerline of the chassis (Roll Oversteer/Understeer are related to this).


Roll Center ... Measured Height for where your chassis/body pivot laterally


Separation ..... The amount of distance between your UCA and LCA at either the body or frame. Will affect where your Instant Center meets and will affect your Roll Axis

 

[EndlessMtnFab]

Like the front suspension, I had some parameters I wanted to meet.


My first requirement was that I *not* be reqiured to cut into the floor. I am aware this puts constraints on my suspension & all related mounting points. It will also limit placement of other items in the process. However, every now and again I have people in the back seat of the Jeep. So I'd like to keep it useable and comfortable for my passengers. Except my mother-in-law. She sits on the bumper rack. :firedevil


Like my front suspension, I want to tuck everything as reasonbly high as possible. The Jeep isn't very tall and the longer wheelbase means a lower breakover angle. Every little bit counts here.


Design has to remain adjustable & street friendly. Not much to really expand on here .....



As with a front suspension, there are several ways to "link up" the rear. First we have the TJ style 4 / 5 link (4 arms, 1 track bar). Next up would be a wishbone setup (2 lowers, 2 uppers mounted to a single point). Some people call this a 3 link setup. Further along is the "traditional" 4 link setup (2 straight lowers, 2 angled uppers). And finally, there is the doube triangulated 4 link (2 angled lowers, 2 angled uppers).



There are other link arrangements available; 3 link rear, radius arm rear, 1 link/grader ball, etc. All of these setups can be used if you have specific functions in mind. I simply trying to keep things simplistic for now.



For "custom" suspensions, 4 link rears are the most common setup. Particularly the "traditional" 4 link. Why? Simplicity. It is easier for the builder to locate the arms and tabs if they are a straight shot. Often times, the arms are right on the bottom or side of the frame rail. This makes tab placement on the axle quite easy. Just measure the width at the rail and carry it over to the axle. This style of suspension is also cheaper because the brackets & mounting points are less complex. On the flip side you might see a phenomenon knows as rear steer / axle walk. In short .. the wheelbase will change as the suspension cycles. One side will have a longer wheelbase than the other, giving the illusion that the axle is turning under the Jeep. This can be countered with longer arms and some tweaking. The problem is ... our uni-bodies do not have a lot of room to spare and limits were we can place things.


The next alternative is the Dual Triangulated 4 link. Here, both the uppers and lowers are angled in opposite directions. This changes how the forces act on the axle (thru the arms) and keeps the housing more stationary as the suspension cycles. It will not completely eliminate the rear steer/axle walk -- especially if your arms are too short. But it's a big step in the right direction. The dual setups are more time intensive to design and build. And often more costly because of the extra parts needed. Slight changes in chassis adjustments tend to have a disproportionately large result when tuning the suspension.



I chose the Dual Triangulated setup for my Cherokee based on a few things. I'm keeping the lift lower, and our XJs have small wheel wells. I'd rather keep the tire in the same place as the suspension cycles (rather than hitting the front or back of the wheel well). Also, there is greater flexiiblity in LCA mount placement at the chassis end ... making it easier to tuck the brackets as high as possible. The disproportion adjustment factor actually works in my favor because of the space limitations of the XJ body/frame (won't run out of room). And, of course, it just looks cool. :wave1:

 

[EndlessMtnFab]

No pictures just yet ... you'll have to deal with it for now. :hang:




As with the front ... There is an computer driven calculator available to cut down on trial & error time (not to mention mathmatical computation time).



I probably have like 8 versions of my rear suspension on the computer based on different variables and thoughts. However, I will take pity on you for reading so much -- and will only post a single file of the final design.

The link calculator is not the " be all / end all " of designs. It's simply an excellent starting point. Being a little off in "real life" isn't going to make your suspension design a failure. Being out in left field is another story.



If you notice in up in the top boxes ... the anti squat numbers are different in the 2 columns. This would be an excellent example of how vehicle constraints affect your placement of the arms & mounting points. Ideally, the uppers should have been a little shorter. However I did not want to create a separate UCA mounting point on the sheetmetal frame rails. Instead ... the more the suspension flexes ... the higher my Anti Squat reaction will be. 80-90% is about the middle point from what I've seen from other builds on Pirate 4x4 and other boards. This is where adjustabilty is important --- it will allow you to tailor your ride based on what you are doing.


Another example of limitations would be my Instant Center point. I would have rather seen the 2 points converge in the upper 2 quadrants of the tire (as opposed to being outside). This is a result of not wanting to cut my floor boards (moving my UCA mounting points higher). Does it mean the suspension won't work? Hardly. Might just react a slight bit different than a similarly built vehicle with a different IC point. It's just me being an excessive, compulsive neurotic.

 

[EndlessMtnFab]

Now that everyone has read all that good information ... it's time to proceed forward.



I met up with Jeremy of RockKrawler at the PA Jeep show and discussed my thoughts on a rear coil setup. At that time, they had just introduced their coil/coilover kits for the Cherokees and I wanted to see how the kit looked. Although the design is excellent, it would not suit my needs on the main premise that the doubler was going to cause interference (crossmember mounts, additional exhaust issues, etc).


I asked Jeremy about purchasing the coil mounts separately and explained to him why I was doing so. He agreed to let me give it a whirl and I had a set on my way to the shop.



Here is what they looked like when they arrived (other than the fact that I removed the shock tabs).

Cleaned up the area and marked the area where the mounts would be welded. Then trial fit them in place. These mounts have been moved back an additional 3/4 of an inch (from RK's original mounting spot). I knew I was going to stretch the wheelbase and had the room to do so.

The mounts are designed to be perimeter welded. I chose to take it one step further with additional plug welds.

Like all my other metal-to-sheetmetal welding, I used the Cold Galvinizing compound where there was contact of parts along the frame rail. I also started to grind down the weld spots and have not ground the final 2 welds.

Could I have made my own? Sure. But I saved a bunch of time & aggravation, which is worth the the investement. I've already done enough custom stuff. :explosion

 

[EndlessMtnFab]

Using the handy dandy calculator .... the angles of the control arms were already set for me. So with a bit of cutting work (probably quite a bit --- but I'm trying to forget the time I spent on them) I had UCA tabs ready to go. Like my front suspension, I incorporated multiple mounting holes to allow me to fine tune the suspension to my liking.

Then made the coil mounts.

The LCA were a bit more complex to make because of the greater angles (compared to the front) and the fact that the joint/bushing was starting to rotate making the bolt sit on an angle. Once I was able to make 2 consistent pairs I was ready to go.

Then I cut, heated, and bent a 1/4 inch plate to act as a skid and tie both tabs together. Ran the skid underneath and then upwards a bit so that it would not act as a shovel. Like all my other LCA tabs .... the joint or bushing has about 1/4 inch of clearance to allow for movement without sticking below any mounts.

 

[Char-Broil]

Very cool, I will have to stop in sometime, my in-laws are near Hazleton. I will be up there this weekend, but unfortunately I have a bunch of work to get done and won't be able to sneak away. Cool build BTW, subscribed :cheers:

 

[EndlessMtnFab]

As with the front suspension .. arms need to be made again. Lower construction is identical (other than length). The uppers are a bit different this time around. Since this rear suspension has 2 uppers, I felt comfortable going with a slightly smaller joint in order to utilize as much room as I could. The same tubing was used (1.5 x .250 DOM) as the front. For the rear links, I decided to use the Rubicon Express Small SuperFlex joint.


RE's normal "small" joint is designed for use with a 10 mm bolt (same as factory). However, they offer the same joint with a 1/2 inch bolt option. You lose a very minor bit of travel .... but not enough to notice in the grand scheme of things. I purchased the ball assemblies from Rubicon and then called Ballistic for mounting studs and threaded bungs (so I could adjust them). And that is what we have here:

I guess we are in AT&T country now. :spin1:

Enough angles to make you cross-eyed. :eyes:

And another quick preliminary shot of the rear crossmember. The upper mounts are tacked in and one set of the lower mounts are tacked in as well.

 

[EndlessMtnFab]

Here is a rough install picture lookiing towards the front of the vehicle (from underneath, of course).

If you look over the UCA (see picture below) you can see the tabs for one of those funky drain hole plugs. This entire area is a bit closer to the UCA tabs than I would like. In and of itself ... there shouldn't be any issues. But if there were ever a severe enough impact that could tweak the crossmember --- the plug and low spot in the floor pan would make contact. Later in this thread I should have pictures of how I plated off the holes to gain extra room.


*note* There are still open pieces of tubing and un-reinforced tabs that have not been welded up at this stage.

Two lowers .... one upper. The other upper is sitting on the floor waiting to be modified at this point.

And here it is coming together.

 

[EndlessMtnFab]

Even the best laid out plans can go awry.



If anyone can recall .... I chose the 14 bolt hubs because of the smaller body that would allow me to retain a 5 bolt wheel pattern. The potential issue was the bolt pattern overlap between the 5 & 8 lugs. With the help of C&M Performance Machine in Michigan ( Hiya Mac! ) an attempt was made to convert it over.


Unfortunately, due to the hardness of the weld and the fact that the bolt patterns overlapped --- I ended up with cracks in some of the stud holes. Wheels studs are an interference fit and it was enough pressure/force to crack where the weld & parent material joined. :banghead:



Did I mention? :banghead: :banghead:



Just in case I didn't. :banghead: :banghead: :banghead:



One thing I didn't want to do ... was try it again. The failure was not related to the work that C&M did, but rather the fact that we were tryng to do something that really shouldn't be done. So, the last thing I needed was ANOTHER failure. I clearly stated much earlier in the thread that I did not want an 8 lug pattern, and now I am required to run one.



A week of scavenging and emails didn't really lead to much success in finding what I was after. I only had one pair of DRW hubs ... all my other hubs were SRW. Thankfully Mac ( Hiya Again Mac ! ) had most of the parts I needed. A few roughly worded emails with vague blackmail threats (something regarding pictures, some sheep, and an oversized latex suit) had the parts coming to me pronto. :angel:


So now .... I am the only idiot in North America with an 8 lug Dana 30. :looser:



Because of the different knuckles I previously installed .... the hubs were a simple swap involving 6 bolts. The only downside of this is that the 8 lug - 3/4 ton rotors & hubs made the front axle wider by roughly 1 inch per side. Mac machined me some 1/2 inch spacers for the rear to close the gap while still keeping the rear track narrower. A narrower rear axle (by a slight amount) improves your turning radius. Does anyone notice poor Mac has been roped into this buildup ?


I know everyone is already snickering at the 8 lug Dana 30. :gag: I already had all the parts here at my place (with the exception of the new hubs required) so I haven't lost any money with this arrangement. On top of that .... I have aquired a free HP Ford D44. I will be shortening this axle at a convienent time in the semi near future. So when/if my Dana 30 breaks, it will be a matter of unbolting the knuckles and yanking the housing from under the Jeep. Then I can bolt in my new HP44 and continue on my merry way.


In my next post I will share a few photos and then continue on with the build up and explanations as needed.



I need to thank Mac from C & M Performance Machine for all his help. While he is a dirty scoundrel that enjoys laughing at my misfortunes (many that I haven't told here) ... he has helped me with parts location, great prices, and general input/advice. If any folks are looking for custom machining or HD driveline parts, defintely look him up. You can find him on Pirate 4x4 under the screen name "Mad Mac"



Just don't tell him I sent you ... he'll charge me more.

 

[EndlessMtnFab]

Thought I would include a few shots of the hub situation ... that way there would be no confusion about how I went from 5 lug to 8 lug.

Pay no heed to the rust .... I threw them in the scrap pile and it rained the next 2 nights. A toothbrush would probably knock most of the rust off. If you look *super* closely at the first picture, you can see the hairline crack in the cleaner section of the hole (at the 5 oclock position). One of the other hubs has an elongated hole as well.

I asked the machine shop to bail me out again .... since I was running around like a chicken with my head cut off. :hang: This time .... I requested the outside diameter be turned down about 1/16 of an inch. I also asked that the back side be cleaned up (removing all the extra material where the wheel studs are pressed in).

Installed the studs this way ....

Studs installed .... showing how the back side was "cleaned up"

 

[EndlessMtnFab]

All hail the 3/4 Ton Dana 30 !!!






:worship::worship::worship::worship::worship:

:worship::worship::worship::worship::worship:

 

[yossarian19]

dude... that axle is a FREAK

If I saw that axle at a social gathering, I would shun it.

Etc. Sweet build man, really amazing fab here. Keep it up!

 

[EndlessMtnFab]

By the time I put the diff cover on it, paint it, etc .... I doubt many people would even realize it's a D30. :laugh3:



Figure the truss adds "mass" to the housing. You can see the "old school" knuckles and inner yokes. And so on .....




Worth a shot :spin1:

 

[dgrigorenko]

dude that thing is pimp! i dig the super thirty thingy