Unlimited04's LJ Build

[NEastUnlmtd]

So, no shock relocators or exhaust mods in the "comprehensive" plan then?

[mudb8]

Originally Posted by Unlimited04

my thoughts exactly. A Rubicrawler + NV241J gives you a great gearing combo and doesn't add any length to the drivetrain.

The search for a sub-60k 03-06 NV241J under $800 shipped to my door has begun

there's one here locally for 950 if I remember correctly...

what was that comment about the 231 being worth putting money in again.....



I believe it got a new sye put in, then they never put in enough oil, I'm certain it didn't leak due to how much silicone it had stuck in it... that thing was toast. I ended up using the sye, in another t-case... hope the temper is still good...

shock relocation is awesome for a few reasons, just not exactly needed with the proper length shocks for the lift height..

[Unlimited04]

Originally Posted by NEastUnlmtd

So, no shock relocators or exhaust mods in the "comprehensive" plan then?

nope. I'll only need shock relocators if I rotate the pinion angle and get interference with the lower spring perch.

don't know how exhaust mods fit with a 2.5" suspension, but if I get rubbing on the shock, I'll probably just leave it for now. May cut the tailpipe off and weld a turndown on if I have to. But so far, no issues....

Eventually I'd like to go to a 2.5" diameter exhaust, but thats waaaaaaay down the road.

[rubidriver]

Originally Posted by Unlimited04

nope. I'll only need shock relocators if I rotate the pinion angle and get interference with the lower spring perch.

don't know how exhaust mods fit with a 2.5" suspension, but if I get rubbing on the shock, I'll probably just leave it for now. May cut the tailpipe off and weld a turndown on if I have to. But so far, no issues....

Eventually I'd like to go to a 2.5" diameter exhaust, but thats waaaaaaay down the road.

Why a 2.5" exhaust, you will loose almost all the back pressure that you have right now?

[Unlimited04]

Originally Posted by rubidriver

Why a 2.5" exhaust, you will loose almost all the back pressure that you have right now?

naw, i'll keeping the cats - all three. The 2.5" OD will just be "cat-back", same diameter as Banks and other aftermarket kits, stock is 2.25". But...thats a few years out, when the stock muffler rusts thru, I add 50k more miles and/or stroker.

AND...found a NV241J in my price range thanks to "provelogear" (Savvy Offroad). Thanks !

[rubidriver]

Originally Posted by Unlimited04

naw, i'll keeping the cats - all three. The 2.5" OD will just be "cat-back", same diameter as Banks and other aftermarket kits, stock is 2.25". But...thats a few years out, when the stock muffler rusts thru, I add 50k more miles and/or stroker.

AND...found a NV241J in my price range thanks to "provelogear" (Savvy Offroad). Thanks !

People that have done banks have reported they feel lost low end power, not all of them... just the ones that know what the placebo effect is. I suspect that it is because the overly huge tail pipe and straight through muffler. Stock is not 2.25, its 2". Ive compared a stock tail pipe to a 2.25" tail pipe and you can easily see that the stocker is smaller. It may just be the tail pipe that you are replacing, but there will still be turbulence.

[Knuckelhead]

I installed the Banks catback and lost low end torque. Installed an exhaust pipe reducer in the end of the 2.5" pipe and got the low end torque back...

[Unlimited04]

Originally Posted by Knuckelhead

I installed the Banks catback and lost low end torque. Installed an exhaust pipe reducer in the end of the 2.5" pipe and got the low end torque back...

hmm interesting. Good to know, thanks!

[Unlimited04]

had some death wooble symptoms the other day, so decided to check the track bar. broke the axle side front track bar bolt this morning checking the torque....today wasnt my day. Spent 5 hours screwing with the t-case linkage too....

The stock track bar bolt is 10.9 and has 9mm shaft, but M10 (10mm x 1.5) threads....which is why its so loose inside the JKS track bar.

Stock Bolt Shaft (9mm):


Stock Threads (10mm):


Normal Class 8.8, Class 10.9 and Class 12.9 Bolt Shaft (10mm):


Normal Class 8.8, Class 10.9 and Class 12.9 Bolt Threads (10mm):


This makes no sense to me, because the OD of the non-thread shaft should be the same as the major diameter as the threads, not the minor diameter. Whatever, typical Chrysler engineering...crap like this is why they went bankrupt.

So the local hardware store doesn't have any hex head 10.9 bolts because they are morons. they only have 8.8 hex heads, and 12.9 socket head cap screws. Then the hardware store guy tried to tell me Class 8.8 = Grade 8.

I bought two hex Class 8.8 and one socket head cap Class 12.9, all M10 x 1.5.

[Engineering Speak]

All 10.9 bolts have a tensile strength of 145 ksi (kilo-psi), all 8.8 bolts have a tensile strength of 116 ksi. For reference Grade 5 = 120 ksi and Grade 8 = 150 ksi. Class 12.9 has a tensile strength of 174 ksi. Source: www.mcmaster.com

The factory torque spec is 55 ft-lbs. BUT - a Class 8.8 M10 bolt can only take 40-45 ft-lbs of torque before the threads distort and the bolt is useless. A Class 10.9 M10 bolt can take ~55-60 ft-lbs. A Class 12.9 M10 bolt can take ~73 ft-lbs.
Source: http://dodgeram.org/tech/specs/bolts/M_bolts.html and http://www.dansmc.com/torque_chart.htm and and http://books.google.com/books?id=_Pk8raJvVaEC&printsec=frontcover&dq=Elect romechanical+design+handbook

[/Engineering Speak]

What does this mean? Since the stock torque spec is at the upper limit of a 10.9 and grade 8 bolt, you can very easily overtorque the stock bolt, causing the threads to deform and the next time you go to use the bolt it is useless and will not torque properly. It will just snap. Thats what happened to me. The solution - buy a 12.9 M10x1.5 75mm bolt and torque to 55-65 ft-lbs.

Also, every M10 x 1.5 bolt you buy from McMaster or a hardware store will have a 10mm OD shaft instead of the stock 9mm, which makes it fit more snug in the track bar (a good thing!). You'll have to drill out the stock washer, I worked it with a 3/8" drill bit for a while. I couldn't find a thick, larger OD 10mm ID washer to match the stock one.

Finished - Class 12.9 Socket Head Cap Screw, Class 10.9 thin washer + drill out stock washer:


I reused the stock nut after chasing the threads with an M10 tap - I chewed them up trying to get the busted bolt out. Torqued to 55-60 ft-lbs and used a bit of blue lock-tite. make sure to tighten the Class 12.9 M10 bolt with an 8mm Allen head - careful not to strip the allen head!

[Unlimited04]

New toy to grin at:




It won't be installed for a long time. Need to save money for some adjustable arms, new rear driveshaft, front u-joint 1310-->1330 thingy, the necessary wiring crap, speedo corrector thingy, etc. So for now, its wheeling next to the futon.

[Unlimited04]

Did some quick wheeling on a trail today to check flex and for track-bar interference.
I can put my finger between Riddler and the JKS track bar. Its close, but doesn't appear I'll have issues at this point. These are all with sway bars connected:


^the front is still like an inch or more off the bumpstop, and the rear is probably 1/2-3/4" off the bumpstop, and I got 2-3 fingers between the flare and the tire. Plenty of room for 33s!



Next issue I've noticed is the passenger side spring perch is about 1/2" smaller than the drivers side. My friend's LJ is the same way. It causes my passenger side spring to rub on the perch. On big bumps or quick braking stops, the spring rubs and makes an annoying clunk that resonates through the entire frame. I can find absolutely no reason Jeep engineers would design the perches like this. There is no potential of sway bar interference, no brake lines, A/C lines or anything that would get in the way of a 1/4-1/2" wider perch...guess its a "Jeep thing". Nothing I can really do to fix it either...the spring is in correctly...


I'm amazed how much better the OME rides on the trail and over washboards. The Jeep keeps the wheels stuck to the ground better and the body stays level better in flexing situations.

[RjAndJeep]

cool coolio

[NEastUnlmtd]

Originally Posted by Unlimited04

^the front is still like an inch or more off the bumpstop, and the rear is probably 1/2-3/4" off the bumpstop, and I got 2-3 fingers between the flare and the tire. Plenty of room for 33s!
What about your control arms there? My shocks and bumpstops have room to move but the stock control arms are bound against the brackets at its fullest droop.

As for the passenger side perch mine has a wider setup.


Nice to see your progress and great documentation.

[JESSETHELJ]

Originally Posted by Unlimited04

Kinda sucks that I have a tummy tuck w/ a t-case drop...

LMAO i know how you feel!

AND holy CRap I thought my spring perch smaller. I just thought i got jiped lol

[jeepfreak4life7]

Very nice. Looks like it's ready for regear and 33's.

How is it on the highway? I know this is a ridiculous question, but notice anything with gas mileage? Your gonna love that OME kit even more after a while. Even with 80k miles on mine, it still felt great.