Libby's are "stiff"

username · **Joined:** Wed Jan 28, 2009 12:42 pm **Posts:** 21

I'm curious/potentially annoyed at a design issue on the liberty (if i'm not incorrect):

I've owned my '06 crd for about 6 months now and haven't had any problems other than oil seepage. Upon inspecting the condition of my wheel bearings (investigating noise that turned out to be tire issues), i realized how stiff the 4wheeldrive system is on this vehicle.

I have always noticed that the libby doesn't coast very well at all, but i thought that was some ridiculous ecu or tranny programming. Why do the 4x4 components have to spin when in 2wheel drive?

I was going to try a test by removing the front drive shaft to maybe free-up some internal resistance, but gear-oil started coming out of the bolt holes. (Why the crap does gear oil need to bee all the way up through the front drive shaft?)

I guess a way around that is to pull the half-shafts and run the same test. Does anyone know if it's safe to drive around without the half-shafts installed?

Maybe my jeep is functioning incorrectly and not disengaging the 4wheeldrive system entirely. I've checked by making tight-ish turns on concrete in the various drive modes. In 2wheel and "full-time", it turns nice and smooth while in "part-time" and 4low it wants to bind.

If this is normal operation, i'm ready for any jeep education about what the advantage is to constantly spinning all these components in 2wheel.

At this point i'm inclined to believe that my liberty could be getting significantly better fuel economy by simply not spinning the half-shafts/frontdiff/driveshaft continuously.

Input is very welcome,
Jay

linewarbr · **Posted:** Tue Aug 04, 2009 12:50 pm

I don't know enough about the 4wd system to comment on it, (this is my first Jeep) the phrase "oil seepage" caught my eye. Where are you experiencing oil seepage from?

Boiler · **Posted:** Tue Aug 04, 2009 1:00 pm

my gas liberty is a horrendous coaster too....

username · **Joined:** Wed Jan 28, 2009 12:42 pm **Posts:** 21

linewarbr wrote:

Where are you experiencing oil seepage from?

origin unknown at this point. My engine block and oilpan are oily but not dripping so there must be a seep from up top somewhere.

username · **Joined:** Wed Jan 28, 2009 12:42 pm **Posts:** 21

Boiler wrote:

my gas liberty is a horrendous coaster too....

That's a good data point. Crappy coasting isn't limited to the diesels; is yours 4x4?

ac5501 · **Posted:** Tue Aug 04, 2009 1:32 pm

username wrote:

I'm curious/potentially annoyed at a design issue on the liberty (if i'm not incorrect):

I've owned my '06 crd for about 6 months now and haven't had any problems other than oil seepage. Upon inspecting the condition of my wheel bearings (investigating noise that turned out to be tire issues), i realized how stiff the 4wheeldrive system is on this vehicle.

While suspended in the air i turned each wheel to feel the resistance, and to my surprise they were harder to spin than any other vehicle i have owned (including a '98 tj). I have always noticed that the libby doesn't coast very well at all, but i thought that was some ridiculous ecu or tranny programming. Why do the 4x4 components have to spin when in 2wheel drive?

I was going to try a test by removing the front drive shaft to maybe free-up some internal resistance, but gear-oil started coming out of the bolt holes. (Why the crap does gear oil need to bee all the way up through the front drive shaft?)

I guess a way around that is to pull the half-shafts and run the same test. Does anyone know if it's safe to drive around without the half-shafts installed?

Maybe my jeep is functioning incorrectly and not disengaging the 4wheeldrive system entirely. I've checked by making tight-ish turns on concrete in the various drive modes. In 2wheel and "full-time", it turns nice and smooth while in "part-time" and 4low it wants to bind.

If this is normal operation, i'm ready for any jeep education about what the advantage is to constantly spinning all these components in 2wheel.

At this point i'm inclined to believe that my liberty could be getting significantly better fuel economy by simply not spinning the half-shafts/frontdiff/driveshaft continuously.

Input is very welcome,
Jay

Just a couple of things.

I say this at the risk of sounding like some kind of fanboy because I have been commenting a lot about the GDE lately. The GDE tune significantly improves the coasting ability in the Jeep. Especially in city driving. I can start coasting up to stop lights and signs much sooner than before (and not piss off everybody behind me). Before the GDE if I tried coasting some of the distances I do now I would have been gang beaten by an angry hoard of drivers.

As far as the binding issue. Im no Jeep expert here, but with Part Time 4wd and 4wd Low, the front and back wheels spin at the same rate. This will cause binding (and damage so don't do it again) when making tight turns on dry surfaces. I like to think of Full Time 4wd as All Wheel Drive (somebody correct me if Im wrong please) front and rear wheels can spin at different speeds so no (almost no) binding on tight turns. It sounds like your Jeep is working correctly in this regard.

vegiH · **Posted:** Tue Aug 04, 2009 1:40 pm

Oil seepage from EGR tube?Mine had that issue,few drops on driveway once in a awhile.............

CRD Joe · **Posted:** Tue Aug 04, 2009 2:18 pm

Im waiting on GDE's HOT tune. Then Im diving in head first. :lol:

username · **Joined:** Wed Jan 28, 2009 12:42 pm **Posts:** 21

ac5501 wrote:

It sounds like your Jeep is working correctly in this regard.

Thanks i'll check out the GDE(?)

Do you know if normal operation is spinning 3 shafts + the gears and fluid in the front diff? Still seems like alot of energy and angular momentum to be generated for nothing in 2wheeldrive.

linewarbr · **Posted:** Tue Aug 04, 2009 2:27 pm

Which side of the engine has the majority of the seepage, turbo side or intake side?

linewarbr · **Posted:** Tue Aug 04, 2009 2:30 pm

username wrote:

ac5501 wrote:

It sounds like your Jeep is working correctly in this regard.

Thanks i'll check out the GDE(?)

Do you know if normal operation is spinning 3 shafts + the gears and fluid in the front diff? Still seems like alot of energy and angular momentum to be generated for nothing in 2wheeldrive.

I definitely recommend the GDE tune also - just keep in mind your mileage gains won't be as good if you drive 85mph everywhere. Ask me how I know. . . :twisted:

Have you tried getting all four wheels off the ground with the t-case in neutral to see if it still displays the same behavior? The 4wd lights on the dash light up based on the shifter, IIRC - so your shifter could be in 2-hi and your t-case still in part-time. That may indicate a shifter linkage problem as opposed to another, more expensive problem.

stoutdog · **Posted:** Tue Aug 04, 2009 2:35 pm

GDE and removing the muffler should help significantly with coasting. I only have GDE at the moment, but I can cruise on flat surfaces at 35mph around 1,100rpms. I never have to put my foot on the pedal to go downhill again

ac5501 · **Posted:** Tue Aug 04, 2009 2:40 pm

username wrote:

ac5501 wrote:

It sounds like your Jeep is working correctly in this regard.

Thanks i'll check out the GDE(?)

Do you know if normal operation is spinning 3 shafts + the gears and fluid in the front diff? Still seems like alot of energy and angular momentum to be generated for nothing in 2wheeldrive.

GDE = Green Diesel Engineering. They have an ECM flash for the Lib CRD.

I wanna say in 2wd the forward shaft is disengaged inside of the transfer case. This would mean the shaft would still spin because its connected through the diff. to each front wheel.

I repeat I wanna say that, but I'm just not that much in the know about the Jeep's 4wd system so I could easily be talking out my stupid.

but I am curious about the answer.

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The Jeep's 4WD system is not the model of efficiency. The driveline losses are quite high, partly due to strong, heavy components that are always rotating even when not needed or in 2WD mode. Some companies in the past developed front axle disconnects (think Ford), however, it was very complex and had warranty issues. The axle disconnects would keep the front axles (half shafts), ring gear, pinion and prop shaft stationary if the vehicle is in 2WD. This would probably gain 2-3 mpg in normal driving.

The front propshaft can be disconnected without any issues and is safe. However, you may not find a big gain in fuel economy as you would only keep the T-case from spinning in 2WD because there is a direct connection between the front hubs, wheels and axle.

You can always ask Jeep to design front axle disconnects for their next generation vehicles! Make sure they don't feed you a line about a pinion disconnect as it is not as efficient of a design. After coming out of bankrupcy, it may bode well for them to start listening to what customers want...the next bankrupcy will not have the "easy out" button.

GDE

username · **Joined:** Wed Jan 28, 2009 12:42 pm **Posts:** 21

GreenDieselEngineering wrote:

The front propshaft can be disconnected without any issues and is safe. However, you may not find a big gain in fuel economy as you would only keep the T-case from spinning in 2WD because there is a direct connection between the front hubs, wheels and axle...
GDE

This is why I was considering removing the front axles for the summer. Any reason this would be bad for the components?

GreenDieselEngineering wrote:

...This would probably gain 2-3 mpg in normal driving...
GDE

That's not insignificant. ~10% more fuel economy would be worth the sunday afternoons required to remove and replace the axles each summer, imo.

Thanks for the responses

geordi · **Posted:** Tue Aug 04, 2009 4:58 pm

GreenDieselEngineering wrote:

You can always ask Jeep to design front axle disconnects for their next generation vehicles! Make sure they don't feed you a line about a pinion disconnect as it is not as efficient of a design. After coming out of bankrupcy, it may bode well for them to start listening to what customers want...the next bankrupcy will not have the "easy out" button.

GDE

You owe me a new keyboard for that one! :lol:

I practically spewed diet coke all over my computer from laughing so hard. While I am inclined to agree that they "SHOULD" start listening to what the customers want to purchase... Do you HONESTLY think that they will? Its the same bunch of clowns running things now, as it was when they declared a 25% sales EXCESS over their planned manufacturing as a market failure!

The country clearly told them that the market WANTS a mid-sized SUV that gets decent mileage (which can only be found affordably with a diesel) And they answered by canceling the USA model and making up excuses. Listening isn't something they will ever start to do, until the engineers take over and kick out all the marketing weenies and MBA fools that have been soaking up all the free government money.

But thanks for the afternoon laugh. I needed that!

tjkj2002 · **Posted:** Tue Aug 04, 2009 5:24 pm

The KJ's 4wd system is not very parasitic as all you think,even with the front diff always "turning" even in 2wd it does not effect MPG's that much(maybe 1mpg at the max).I ran around for one year with no front drivetrain(no front diff,CV's,or front driveshaft) and did not see any MPG improvement at all with less parts turning and less weight to boot(same driving style,"drive it like you stole it").

You might want to keep your fluids fresh since my KJ coasts just fine.............

I change my F/R diffs every 12,000miles,t-case every 6000miles,and the trans fluid every 15,000miles.

onthehunt · **Posted:** Tue Aug 04, 2009 5:36 pm

Just about all 4-wheel drives operate like this. I would not recommend the axle disconnects. Not worth the gains imho. An all wheel drive system would be much better. They are usually really light duty though. Life is full of trade offs. You could always look for a 2wd Cherokee.

95BadBoy · **Posted:** Tue Aug 04, 2009 7:07 pm

username
The system in our KJ's will not see any real gain by removing your front dshaft or as stated by tjkj2002 without diff and CV's. This idea has even been tested on TJ's many times. 1 MPG gain at most - many got 0 differance. Not worth the effort for such a minimal gain if any at all. By design everything turns when you are moving.
Your coasting can/will improve with the GDE tune.

nursecosmo · **Posted:** Tue Aug 04, 2009 7:34 pm

Just wondering, how on earth the engine tune could possibly improve the coasting ability of the CRD? No tune is giving any more fuel than another @ 0% pedal depression, whether it is the GDE, Inmotion, or OE. The same goes for the boost parameters.

Libby's are "stiff"

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