Any Wrangler JK owners - 3.8 V6 is it that gutless?

[mancat 2,368]

Well we test-drove an Unlimited Rubicon yesterday. It was 2011 with 3.8 and auto - basically the combo I was hoping for. I was pretty impressed with the performance and handling. The long wheelbase is going to be far more comfortable than my SWB TJ, and the 3.8/auto/4.10 gearing combo performed exactly like I was hoping. Wow.. I couldn't believe how much more room there is in the JK Unlimited. I would never have to bend over backwards to fit my hunting/camping/hiking shit into the Jeep again, nor do I have to swap the back seat back in when I think I might have passengers in the back.

 

We looked at some Unlimited Sport models, but almost all of them were 3.73 gearing with open rear. I want 4.10 with L/S minimum, and it looks like the Rubicon is almost the only way to get it.

 

So.. Now the only difficulty is going to be in finding a Rubicon that still has manual windows/locks, hard top, and doesn't have the fancy-ass sound system that takes up room in the back with the ridiculously large subwoofer case.

 

I will cry like a little girl when I trade in my TJ.. It has been a very reliable Jeep and has taken my wife and I on a lot of fun trips over the last 7 years.. It has a "good soul" and has been a good friend. My wife thinks I'm too sentimental over vehicles.. That's fine - she may never really get what it means to be a gearhead.

[XD45 7,124]

The 3.8 was an improvement over the 4.0 I6.

Just slap yourself right now. The 4.0 is a legend in the Jeep community.

[Ronin38 2,117]

We looked at some Unlimited Sport models, but almost all of them were 3.73 gearing with open rear. I want 4.10 with L/S minimum, and it looks like the Rubicon is almost the only way to get it.

 

From the factory... Or you could swap in a Detroit Locker or whatever else you want later.

 

I'm not familiar with the details of the Jeep packages... I don't know if you can get the hard top in a package without the fancy radio? Have you thought about ordering one with just what you want? (If you have the time and patience to wait for it.)

[avnate 335]

 

The 3.8 was an improvement over the 4.0 I6.

Just slap yourself right now. The 4.0 is a legend in the Jeep community.

 

And no one disputes that.

 

The 4.0 was a staple of Jeep for years. The 3.8 was an improvement in terms of fuel economy and meeting Government regulations. As I said both were sluggish. My opinion is one of that an engine is an engine and Jeep enthusiast will always modify and upgrade as their needs grow/deem fit. Hence the Hemi and 4BT swaps that became commonplace. And yes even the 4.0 was swapped as it was not the end all be all of the wheeling community, which has been begging for a diesel for years.

[XD45 7,124]

 

 

The 3.8 was an improvement over the 4.0 I6.

Just slap yourself right now. The 4.0 is a legend in the Jeep community.

 

And no one disputes that.

 

The 4.0 was a staple of Jeep for years. The 3.8 was an improvement in terms of fuel economy and meeting Government regulations. As I said both were sluggish. My opinion is one of that an engine is an engine and Jeep enthusiast will always modify and upgrade as their needs grow/deem fit. Hence the Hemi and 4BT swaps that became commonplace. And yes even the 4.0 was swapped as it was not the end all be all of the wheeling community, which has been begging for a diesel for years.

 

Why would anybody want a diesel 4x4? All that low-end torque and reliability and longevity and fuel economy... Bla.

Edited August 2, 2013 by Darth Saigus

[avnate 335]

 

And no one disputes that.

 

The 4.0 was a staple of Jeep for years. The 3.8 was an improvement in terms of fuel economy and meeting Government regulations. As I said both were sluggish. My opinion is one of that an engine is an engine and Jeep enthusiast will always modify and upgrade as their needs grow/deem fit. Hence the Hemi and 4BT swaps that became commonplace. And yes even the 4.0 was swapped as it was not the end all be all of the wheeling community, which has been begging for a diesel for years.

 

Why would anybody want a diesel 4x4? All that low-end torque and reliability and longevity and fuel economy... Bla.

 

I know right.... People and their crazy ideas/wants. All crazy talk.... crazy talk I tell ya!

[G O B 3,516]

Go with the 2.73 gears, and put a low low kit in the Xfer case. Keep your highway mileage, and get even better crawl ratios.

[mancat 2,368]

 

We looked at some Unlimited Sport models, but almost all of them were 3.73 gearing with open rear. I want 4.10 with L/S minimum, and it looks like the Rubicon is almost the only way to get it.

 

From the factory... Or you could swap in a Detroit Locker or whatever else you want later.

 

I'm not familiar with the details of the Jeep packages... I don't know if you can get the hard top in a package without the fancy radio? Have you thought about ordering one with just what you want? (If you have the time and patience to wait for it.)

 

 

No trust me I have gone through this before on my TJ.

 

It's not adding a locker that's a pain in the ass, it's regearing. You can easily add an LSD or locker to an existing gear setup by just measuring gear backlash and mesh, etc. to make sure that you maintain it when you replace the carrier. Setting up different gears is a pain in the ass just to go from 3.73 to 4.10.. I have the tools required to set up gears, but I hate doing it. I'm not doing it again on a Jeep that I intend to run as a DD.

 

As far as the hard top goes, adding the wiring, plumbing, and relays takes more time and money than adding a soft-top. Many of the factory soft-top Jeeps do not have the hard top provisions, unless they're dual-top sales.

 

I'm perfectly fine with buying an aftermarket soft-top, but not the other way around.

 

As far as the 4.0 goes.. It's a great engine, but just couldn't meet the economy needs that Jeep had, and I believe there was also coming problems with crash safety - somewhat difficult to get a long straight-six to dump downwards on collision in a small vehicle with minimal cab space. Mopar also claimed that the 4.0 tooling was nearly worn out after nearly a half century of tooling 258 and 4.0 blocks/heads/etc. I wish Jeep would've looked into doing a DOHC version of the 4.0 - probably would've solved a lot of the economy problems, and been an awesome performer that is well-matched to the types of driving a Jeep does - e.g. flat torque curve with a relatively low peak RPM.

 

In my experience, most people that complain about the performance of the 6cyl engines in Jeeps, actually want a regear job, but they don't seem to realize it for whatever reason.

 

 

 

Go with the 2.73 gears, and put a low low kit in the Xfer case. Keep your highway mileage, and get even better crawl ratios.

 

 

Nope.. No way in hell. I had 3.07s on my TJ for a long time and even with 30s it was a pig. Might work OK in flat-land country, but I don't live there.

Edited August 2, 2013 by mancat

[MT Predator 2,294]

 

We looked at some Unlimited Sport models, but almost all of them were 3.73 gearing with open rear. I want 4.10 with L/S minimum, and it looks like the Rubicon is almost the only way to get it.

 

From the factory... Or you could swap in a Detroit Locker or whatever else you want later.

 

I'm not familiar with the details of the Jeep packages... I don't know if you can get the hard top in a package without the fancy radio? Have you thought about ordering one with just what you want? (If you have the time and patience to wait for it.)

Rubicon has factory lockers. Way different than a limited slip diff.

[avnate 335]

The Rubicon's D44 rear axle has a gear-based limited slip differential that works when the locker is disengaged. At least this was the case up to 2006. After that I believe they went to BLD.

 

All Rubicons came standard with factory lockers (since 2003 when the Rubi was introduced) either air or electric.

[Mullet Man 2,114]

Lunchbox lockers FTW. Sahara model come standard with an LSD in the D44.

[mancat 2,368]

The Rubicon's D44 rear axle has a gear-based limited slip differential that works when the locker is disengaged. At least this was the case up to 2006. After that I believe they went to BLD.

 

All Rubicons came standard with factory lockers (since 2003 when the Rubi was introduced) either air or electric.

 

yep this is correct. the Rubicon D44 runs as an LSD when unlocked.

 

edit: I just looked this up and in fact the JK D44 did away with the non-locked LSD.. you're correct. I guess I need to look into how I could get an LSD of some type working with the JK Rubicon D44 rear.

Edited August 3, 2013 by mancat

[mancat 2,368]

After reading some more into it, the JK brake-lock differential and traction control seem to do much better than an LSD in the same conditions.. I'm really going to have to read more about the available systems before I start getting too picky about having a rear LSD.

 

Just trying to do all of my research.. Last time I bought a Jeep, I basically bought it blind as-is.

[MT Predator 2,294]

After reading some more into it, the JK brake-lock differential and traction control seem to do much better than an LSD in the same conditions.. I'm really going to have to read more about the available systems before I start getting too picky about having a rear LSD.

 

Just trying to do all of my research.. Last time I bought a Jeep, I basically bought it blind as-is.

If you are looking at Rubicon, you got a locker in both ends. No worries about traction. The traction control you are probably thinking of is a Stability Control something or other. If it gets squirrely on wet pavement and loose dirt in 2WD, it applies the brakes to whatever corner it needs to apply it to so it straightens out. I have a button to turn it off if I wish to. If you throw it into 4HI or 4 LO, it is automatically turned off. In 2WD, on loose dirt, mud, etc., it is damn near impossible to get it to fishtail or go sideways with it activated.

Edited August 3, 2013 by MT Predator

[mancat 2,368]

OK in that case I'll probably be satisfied with that system in lieu of having an LSD. That is the situation I wanted an LSD for - 2WD on wet/slick pavement or snow/ice.

 

I'm not very familiar with a lot of the new ESC systems.. Just used to the old mechanical traction aids.

[avnate 335]

This is what is currently being used in the JK.

 

[avnate 335]

If you throw it into 4HI or 4 LO, it is automatically turned off.

 

4 Lo uses a modified program for Stability Control that acts as a Brake Lock Diff. When the lockers are engaged then the ESC/BLD is overridden and turned off.

[Ronin38 2,117]

This is what is currently being used in the JK.

 

Thanks! I did not know that. Very nice system.

[netpackrat 566]

 

 

Just slap yourself right now. The 4.0 is a legend in the Jeep community.

 

 

And no one disputes that.

 

The 4.0 was a staple of Jeep for years. The 3.8 was an improvement in terms of fuel economy and meeting Government regulations. As I said both were sluggish. My opinion is one of that an engine is an engine and Jeep enthusiast will always modify and upgrade as their needs grow/deem fit. Hence the Hemi and 4BT swaps that became commonplace. And yes even the 4.0 was swapped as it was not the end all be all of the wheeling community, which has been begging for a diesel for years.

 

 

 

The 4.0 was a great engine, but it should never be forgotten that we got it because that was what AMC chose to stick us with. My 1970 CJ-5 has a factory V-6 that is a really great engine that Kaiser bought from Buick and used in the Jeeps for several years. Then AMC came along and bought Jeep, and got rid of the V-6 because they already had their own 6 cylinder engine. They had to lengthen the frame to fit it, and the first few years had problems with the frames cracking because it was never meant to be that long, or to deal with the torque of a straight 6. Then Chrysler come along later and buys AMC, and chooses to stay with the legacy motor.

 

What the Jeep has really needed all this time is a V-8, but we'll never get one because it will kill them on the idiotic CAFE standards. We have a 4.7L v-8 in our Commander and it is an outstanding engine that would be a natural choice for the Wrangler except for the government getting in the way and fucking everything up, as usual. A diesel would be okay up here for a summer Jeep, but I expect mine to start at the trailhead at 20-30 below, cold soaked after sitting for days and with no power available for pre-heat. So a gas motor is unfortunately the best choice.

Edited August 4, 2013 by Netpackrat

[MT Predator 2,294]

 

If you throw it into 4HI or 4 LO, it is automatically turned off.

 

4 Lo uses a modified program for Stability Control that acts as a Brake Lock Diff. When the lockers are engaged then the ESC/BLD is overridden and turned off.

Yeah I forgot to add those details. It really works well in 2wd to keep it straight but it robs you of power/momentum when it applies brakes. Ok for wet/icy roads. I tend to turn it off when I am offroad and really don't need to be in 4wd. That way, I can keep some momentum going running through soft stuff like sand which is common here in FL out on pig trails. You should have seen what that ESC system did when I ripped the front trac bar mount off the front axle! Talk about fucking Death Wobble! It couldn't decipher what was going on and was hitting brakes erratic and nearly threw me off the trail at 15 mph. After I figured out what happened, I turned it off and limped home so I could fix it. I really need to break down and buy an under the hood welder so I can patch that kind of stuff back together on the spot!

[Dad2142Dad 6,559]

Arise ye olde thread for some humor, craigslist add for a jeep. Would not surprise me one bit if this was a forum member..........

 

http://www.uproxx.com/webculture/2013/10/check-balls-texas-mans-craigslist-ad-jeep-wrangler/

[storm6490 2,768]

OP

 

check out http://jkfreaks.com/

 

It is gutless but you can do a lot to it.

[mancat 2,368]

Arise ye olde thread for some humor, craigslist add for a jeep. Would not surprise me one bit if this was a forum member..........

 

http://www.uproxx.com/webculture/2013/10/check-balls-texas-mans-craigslist-ad-jeep-wrangler/

 

HE had me until "more golfing"

 

FWIW I am still in the game for a JKU but probably not until springtime. I have been fixing all of the little things "wrong" on my TJ In the meantime to increase its trade-in value.

[menace667 194]

To jump in here, i have a 2010 mountain edition, hard top, and love it. Is a daily driver as you said yours will be and the BF goodrich MT tires are perfect for sand and mud on the stock vehicle. I had several jeeps before this one ranging from a 1998 all the way to a loaded 2012 sahara (how i got my wife into jeeps) and besides a 2008 lifted soft top 2 door all have been wonderful. The 2008 models were garbage on many levels. Mine had the ignition issue where it would build up static electircity and short the vehicle out which was a ton of fun.

 

My wife has a chrysler 200 with tye penestar in it, and that is a quick motor, but not sokething i want in a jeep. I think the 3.8 is a better option. Good enough for highway use and good enough for dirt.

[mancat 2,368]

menace, I was pleased with the performance of the 3.8 when I test drove a Rubicon. I drive like a grandpa and do not have a huge demand for power, rarely go over 65mph on the freeway.. Primarily all I want is the vehicle to be able to move with reasonable effort when hauling a load or towing, good low-speed performance e.g. on hills and off-road - this is mostly in torque and axle gearing. Do not need to throw a V8 at it.

 

Chrysler also has a spotty track record with some of its recent OHC designs.. I do honestly prefer a pushrod valvetrain design and consider it to be a more reliable design over the long haul, but some of the most durable engines in the world are OHC - e.g. Toyota R series engines.

 

Anyone know of any major problems with the Pentastar yet?

[Mullet Man 2,114]

I'm at 12k miles on my late production '13 JKU, can't comment on reliability yet. When it gets up to 275k like my 4.0 XJ, then I'll chime in. ;P.

Oil changes are so easy on the pentastar, I literally laughed the first time I did it. The cartridge filter is on top of the motor, in the front. Absolutely zero mess involved. It's been a rock solid performer so far tho. Better mileage then my XJ and from what I read of the 3.8, it bests it too. However the torque is lacking, it doesn't have the jump and grunt that the 4.0 does when you mash on it from a stop but upper rpm throttle mashing like highway passing scenarios, the pentastar beats it. But that's to be expected of an OHC motor. I wanted a JKU and from all my research, the pentastar was the way to go. 

 

I did read of some early cylinder head issues in the '13s but from what I gathered, it has been remedied.

 

I'm a pushrod guy too, I much prefer late model GM over Ford.

Edited November 8, 2013 by Mullet Man

[Mullet Man 2,114]

I'm at 58,xxx+ miles now. It's been rock solid so far. I have made some changes to make it more of a Jeep though. These JKU's are EXTREMELY capable off road. Like mind bogglingly capable in basically stock form.

Edited August 15, 2015 by Mullet Man

[Mullet Man 2,114]

73,xxx miles now.

 

Changed the leveling kit from a spacer setup to a spring kit. Much better ride and a little more down travel of the suspension.

Went with an LoD Armor Lite shorty front bumper (42lbs).

It's going in the shop this Wednesday for 4.56 gears, complete axle rebuilds and Detroit Truetracs in the front and rear.  

Changing my tires to a 295/65r20 Cooper STT pro, tall and skinny (true 35" tire). I've hand siped the tires myself for better winter and rain performance. Those will be going on next weekend. I want to see how peppy it's going to be with the current tires and new gear sets before I change them.

 

After I put on the bigger wheels and tires last year and took it to Silver Lake sand dunes, it was an absolute turd in the soft sand, which was to be expected. Struggled going up the long and steep sand hills with factory 3.21 gears.

 

Just did brakes a couple weeks ago. Over 70,000 miles on the factory brakes and the fronts were showing about half the pad life left (impressive). The rears were absolutely shot, literally flaked apart and rusted all to shit. One rotor was toast. The factory BLD system is very hard on rear brakes in these JK's. First time in my life that rear brakes were shot before the fronts.

I'm going to upgrade to the MOPAR factory big front brake kit in the not too distant future, to get back stopping power that's been lost. 

Edited April 17, 2016 by Mullet Man

[patriot 7,197]

 

Chevy small blocks are common as sand and will definitely get you all the power you need...and more. 327,350, and 383 small blocks are the ones you want to look for.

Am I the only one who finds the commonality of them plainer than vanilla when I find them in a build? Choosing virtually anything else offers more character to a build.

 

I can't even begin to describe how dissapointed I am when I find them in old buicks and oldsmobiles...

 

The're all over the place...because they're popular, durable, powerful, long-lasting, easy to work on, and parts are inexpensive.

 

Character... What you build when you wish you'd have done it right the first time.

[james lambert 3,059]

I have an 08 Rubicon JKU hard top

 

It has all the goodies, 5:13 gears 35'' tires lifted winch bumpers sliders super chips stuff ect ect

 

It wont pull my camp trailer, but it will go down the road at 80 all day long, feels a bit underpowered, passing sucks.

 

I plan on the hemi conversion some day

I have 112,000 miles so far