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  #16  
Old March 29th, 2012, 10:22
frijolee frijolee is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Thanks for the compliments all. Please keep the advice coming. I got into engineering because of my love of wrenching so my vehicles tend to progress slowly over time. E.G. the RX7 recently went widebody.

Spare Tire Carrier:

One of the first orders of business was what I could do about the full sized spare. A spare’s not doing me any good if I don’t carry it with me but when I purchased the vehicle it only fit lying down in the back and that seemed to take up the whole trunk.

Did a bunch of poking around, looked at some pre-fabbed units but didn’t find what I was looking for. I ended going the DIY route using a 1750 lb trailer spindle kit with sleeve (<- liked that because it made integration into my existing bumper easier.)
http://www.comp4x4.com/Tire-Carrier-Hinge-Kit-HEAVY-DUTY-1-3-4-Spindle.html

Lots of folks seems to be using 3/16 wall tubing but that seems crazy heavy given I’d drag on my bumper before I hit this. I went with a couple sticks of 2x2x0.125” tubing and doubled up the section at the pivot.



Should vastly improve the moment of inertia where the bending is highest at the base of the cantilever. I also ground all the critical welds smooth to get rid of any notch factor and improve fatigue life. I also have a limit strap (black and yellow webbing sticking out in the above shot) to keep it from over rotating.

Latch is a DeStaCo 344-R w/ redundant safety catch.
http://www.destaco.com/assets/docs/en/ds/324_334_344.pdf



Only downside I’ve found is that the red rubber handle deteriorates slowly in the sun. It faded to pink and then started exuding black sticky crap. I just scrape it with a blade periodically and it’s been fine.

The key twist to my carrier: I designed it to use two positions. I can rock the spare down low when I’m driving on the street so it doesn’t mess up rear visibility but then rig it up high when I’m out wheeling so I don’t compromise departure angles.

Low:


High:


The tire interface portion is held on via two large bolts interfacing to three holes w/ crush sleeves so all I have to do is loosen one, pull the other and then flip the assembly upside down.



Naturally the license plate holder is reversible as well.



I don’t have a good picture of it installed but I found a pretty cool little product for the license plate light. It’s one less reason to get pulled over at night and LED’s bring out my inner ricer.
http://www.4x4xplor.com/ORO-LitePLATE.html

Definitely happy with the end result. It’s within a 1/2” of the hatch, both down and at the license plate molding. Random shot on the trails to give you an idea how tight this is to the bumper…



Jeep flexes well, albeit I keep knocking off the rear fender flares. I probably have some additional trimming coming. The build was just me and chop saw (plus an angle grinder to notch the bumper). Definitely had fun figuring out all the angles to handle the horizontal jog to help keep it tucked tight. Had a friend with a TIG burn it all together for me.

BTW: Props to Luke from Frontier 4x4 (glad you found me fella) for the initial build. I didn’t buy this 2000 miles from home for nothing.

Last edited by frijolee; March 29th, 2012 at 10:32.
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  #17  
Old March 29th, 2012, 12:15
Luke Graham Luke Graham is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Thanks. Nice to see it's getting wheeled.

Alison just saw this and says she kinda misses it, she really liked it. But she's commuting 50 miles each way to work right now so she doesn't miss the mileage.
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  #18  
Old March 29th, 2012, 12:41
sunburned sunburned is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Awesome looking tire carrier, very well done.

Quote:
Originally Posted by fallacist View Post
being an engineer, I'm sure you'll figure it out and make me look foolish, but I had to fold down the rear seat, take my front wheel AND my seat off to fit my bike in the back of my xj....
I'm an engineer as well and I couldn't figure out a good way to mount the bikes either. Of course you'll have to take off the front wheel and fold down the seats, but I didn't like having to move the seat as well. I bought a fork mount to attach to the back of the rear seatback, but I wanted to carry the bike without folding down the seats and I didn't want it way up on the roof either.

Came up with this instead. I wanted to mount fork at the top of the hatch, but I couldn't get to the bolts on the backside to put on nuts, so that idea was nixed. Just absolutely no way to do it, so I flipped the bike over. Sucks because I can't get in the hatch without taking the bike off, but it worked for my trip to the Outer Banks last year.

Big ring on the crank misses the window by maybe half an inch. I'm assuming my mtn bike will fit fine with smaller sprockets. Of course now I have a new road bike with a standard crank instead of compact, so it probably won't fit...

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  #19  
Old March 29th, 2012, 12:55
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Vanimal Vanimal is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Quote:
Originally Posted by sunburned View Post
Awesome looking tire carrier, very well done.



I'm an engineer as well and I couldn't figure out a good way to mount the bikes either. Of course you'll have to take off the front wheel and fold down the seats, but I didn't like having to move the seat as well. I bought a fork mount to attach to the back of the rear seatback, but I wanted to carry the bike without folding down the seats and I didn't want it way up on the roof either.

Came up with this instead. I wanted to mount fork at the top of the hatch, but I couldn't get to the bolts on the backside to put on nuts, so that idea was nixed. Just absolutely no way to do it, so I flipped the bike over. Sucks because I can't get in the hatch without taking the bike off, but it worked for my trip to the Outer Banks last year.

Big ring on the crank misses the window by maybe half an inch. I'm assuming my mtn bike will fit fine with smaller sprockets. Of course now I have a new road bike with a standard crank instead of compact, so it probably won't fit...

i have a hitch rack i can use, but something about carbon hanging out in the wind bothers me. maybe it's the retread that my buddy's truck kicked up on the highway and did some pretty nice damage to 2 cx bikes. i typically just use my saturn vue. i can fit at least 2-3 bikes inside without lowering the seat or removing wheels, and i can leave up one section of the 60/40 rear seat.
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  #20  
Old March 29th, 2012, 18:36
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clean4drxj clean4drxj is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Nice XJ!.. If you want better mileage you can do a few bolt-ons(exaust,cai, oversized TB) and maybe gain a few mpg but don't expect to see anything about 15/16 mpgs. I would seriously think about investing in a double shear trackbar system(rockkrawler/ clayton).
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  #21  
Old March 29th, 2012, 19:34
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TRCM TRCM is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

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Originally Posted by zachandandy View Post
These fuel economy guys need to come back to earth. A stock xj with the straight 6 auto and 4wd was rated at 18 highway. Lifts and bigger tires do not increase fuel economy period. 13 combined sounds about right if you drive it. Hyper mile your ass off, following big rigs at 60 and you might see 20.
Really ?? Very Nice Cherokee BTW !!

My 96, which is stock except for a 3" lift (still has stock tires on it), and 158k on the ticker, knocks down 21-22 GPS mpg on the highway regularly. I do drive the speed limit, but still...

My 88 with 350+ k on the ticker, locked rear, 2" lift, and 31's gets 15-16 GPS mpg highway, and would do better if the AW4 wasn't on its way out.

BTW, both are 4.0, AW4, 4x4 cherokees...........So I'd say something ain't right with your MPG.

Last edited by TRCM; March 29th, 2012 at 19:41.
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  #22  
Old March 29th, 2012, 19:46
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Vanimal Vanimal is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Quote:
Originally Posted by TRCM View Post
Really ??

My 96, which is stock except for a 3" lift (still has stock tires on it), and 158k on the ticker, knocks down 21-22 GPS mpg on the highway regularly. I do drive the speed limit, but still...

My 88 with 350+ k on the ticker, locked rear, 2" lift, and 31's gets 15-16 GPS mpg highway.


So I'd say something ain't right with your MPG.
my jeep runs fine, and 10-12mpg on 31's is average. i dont believe anyone who claims higher than the epa ratings, which are typically pretty liberal as it is.
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  #23  
Old March 29th, 2012, 21:22
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DeftwillP DeftwillP is online now
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Quote:
Originally Posted by TRCM View Post
Really ?? Very Nice Cherokee BTW !!

My 96, which is stock except for a 3" lift (still has stock tires on it), and 158k on the ticker, knocks down 21-22 GPS mpg on the highway regularly. I do drive the speed limit, but still...

My 88 with 350+ k on the ticker, locked rear, 2" lift, and 31's gets 15-16 GPS mpg highway, and would do better if the AW4 wasn't on its way out.

BTW, both are 4.0, AW4, 4x4 cherokees...........So I'd say something ain't right with your MPG.

Yup. You're the norm here and anyone who claims to be getting less than 20 mpg is the exception. You solved it.
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  #24  
Old March 29th, 2012, 21:45
frijolee frijolee is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

The nice thing about treatting this as a secondary vehicle is that mileage wasn't the primary concern. Thus far as an all arounder, I've been really happy. I'm might try having the injectors cleaned at some point, but improving that is more of a bonus than a real goal.

To be fair that 13 mpg I found on the big drive back to California was doing 80-85, the whole way. I pretty much think a lifted XJ has all the aerodynamic properties of a brick. But at least it's an attractive brick!
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  #25  
Old March 29th, 2012, 22:02
frijolee frijolee is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Thought Iíd give this one away with the flexing shot above but seems like no one picked up on itÖ

Gas Tank Skid:

Having done a few fast car projects Iím not used to the concept that weight doesnít matter. Between that and the fact that a car fire usually ruins your day (even if you get it put out), I wanted to build a gas tank skid so Iíd have one less thing to worry about under the vehicle when I bang it on something. Plus the bottom side of this jeep was just about as clean as the top and Iíd like to keep it presentable (the boulevard part of the build, right?)

I read that there was an OEM skid but it was only 1/8Ē steel and still weighed 30+ lbs. Thereís also the problem that most of the OEM skids seem to have rusted their way to dust by now. You can buy an aftermarket skid (usually made from the 3/16Ē steel that the custom fab folks seems to love) but you put about 70 lbs under the back of your vehicle and that seemed a little nuts to me just for some gas tank protection.

Instead I did a little bit of math and figured out I could make this out of 1/4Ē aluminum plate and itíd still have greater bending stiffness than the steel. I did go with 5052 aluminum rather than 6061 because itíll take an impact better. Since Iím welding it (but didnít plan to heat treat) Iíd lose a lot of the properties of the stronger alloy anyways.


Didnít take any pictures of the cardboard mock-up but it looked exactly like what I built (only made of cardboard and tape). Didnít both mocking up the gussets.



Note I added 7/8Ē drainage holes in all four low corners in case I go wading as Iíd rather carry back memories of a pretty stream, rather than the stream itself.

The rear bumper had a few supports built in that ran along the rear unibody rails so I replicated those into my skids. Getting the fit correct was a little challenging but Iím happy with the end result. Itís well gusseted and 100% welded inside and out.





Oh and it weighs one lb more than the stock skid while being a hell of a lot stronger (less than stock if you include the supports I removed). Looks gangster from the back too.

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  #26  
Old March 29th, 2012, 23:55
crimsondragon crimsondragon is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

That is a sick tank skid. How much do you have in it total?
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  #27  
Old March 30th, 2012, 00:04
frijolee frijolee is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

That was about $150 in aluminum and maybe 20 hours labor, 15 or so being the actual fab. I don't know how many sticks of filler rod are in this thing but it was something like 40 linear feet of weld. We fixtured the heck out of it to keep it from moving around too much and it still warped a bit. It was mostly just the flanges along the edges and thankfully it pulled back down flat when we bolted it in.

It's pretty easy to lift the rear of the jeep via the skid and a regular mechanic's jack now (which I guess was kind of the point if a rock would be doing the same thing for me). The skid spreads the load out to the frame rails nicely.

Last edited by frijolee; March 30th, 2012 at 00:12.
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  #28  
Old March 30th, 2012, 00:16
frijolee frijolee is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

For those folks referencing the dual shear track bar... Where's the failure point with the cantilevered setup I have now? Is it the bracket that lets go or the stud? Hey Luke, if you're reading this, do you remember if the stud is OEM or part of the BDS kit?

Since my track bar itself is already a pretty nice piece (adjustable and included with the BDS long arms), I might try to retrofit something to support that a bit more while trying to avoid replacing the whole bar. FWIW that stud on the driver side frame rail has a little play in it. The BDS folks tell me it's rebuildable though.

Last edited by frijolee; March 30th, 2012 at 00:20.
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  #29  
Old March 30th, 2012, 02:04
crimsondragon crimsondragon is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

I would definitely pay top dollar for a skid like that. The weight of my JCR is what's preventing me from mounting it permanently to my Jeep.
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  #30  
Old March 30th, 2012, 07:31
SolarBell SolarBell is offline
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Re: Joel's multipurpose XJ build (rocks/boulevard)

Quote:
Originally Posted by frijolee View Post
That thing looks amazing. I'd expect to see that kind of quality coming from TnT or JCR.
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