So this is my latest issue. I just got the hot tune from GDE and loaded it up last night. Huge power difference, so much so that the new TC will be soon. But I digress. About 3 hours ago, the abs and parking brake light came on, plus a tone announced it. I did a quick Internet search and found mention of a dirty rear axle sensor. I went and popped it, to which I found that it had a milky film on it. I popped the rubber plug and dipped my finger in the axle fluid, and indeed it is milky white/light brown. I honestly don't know what color it's supposed to be but I assume its not good. When I first purchased this Libby last July I took it in to have all the fluids changed. I know that the front diff isn't that color. Are these related?

Milky fluid is letting you know that you have water mixed in with your gear oil. I would change it very soon.

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SOLD - 2006 Jeep Liberty CRD Limited
Gen2 Fuel Head - Magnaflow Exhaust - Ram transmission swap - In-Tank Lift Pump
Moab Wheels - 245/75/R16 LR E Cooper Discoverer AT3 Tires - OME Lift 790/90009 948/60069 - Etecno Glow Plugs - V6 Airbox
Pic of my Jeep!

Sooo all over it as we post. My calm posting demeanor masks my panic...

Lol. If you didn't go offroad or tow for a long time, chances are that your axle is fine. Just take out the oil, try a synthetic gear oil thats not the most expensive, drive few miles, then replace it with a good one. I dont remember the specs for it but should be in the book. I use mobil 1 synthetic, it comes in an expensive version (better) and cheaper version (good - its per book for normal driving, not severe, like offroad/towing). If memory serves me right the specs for the normal is 75w 90 and better is 75w 140.

Also, check the filling plug to make sure it.doesn't allow water to go in.

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2005 kj CRD, samco, suncoast tc, provent, Kennedy lift pump, GDE ECO full torque, 2nd gen filter head, 245/70/16 a/t tires, mopar light bar, fumoto oil valve, OEM Skid Plates, ARB Front bumper and HD OME, tru cool LPD47391 40k GVW tranny cooler (stock cooler delete), FF Dynamics e-fan and shroud, rocker arms replaced, HDS2 190F thermostat.

Well, that's done. I inspected every tooth for signs of wear and it all looks super clean and machined. Friction modifier? I guess I will pick some up and add it. Still, it didn't address the dash light issue. The owner's manual mentions that the triple combo of ABS, brake light and tone as a sign of imminent brake failure?? I find that somewhat hard to believe. Still hoping someone has had this issue before and can advise me...

Modifier only needed if you have the clutch type factory LSD.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

There was a recall issued for the 2005 CRD whereby the factory filled up the rear diff with the wrong type of oil.
This chewed up the speed sensor so these Jeeps were supposed to go to the Dealer to have the oil drained, new correct oil added and new diff sensor fitted. Possibly this is the case with your Jeep and when you took it in to have all fluids replaced they did not change the rear diff oil and this is the milky sludge you saw!

So maybe your speed sensor has been a bit damaged in the meantime although you can obviously still get your speed reading?

You only need the Mopar Friction Modifier if you have the Trac loc LSD diff at the rear....there should be a label on the rear axle stating if Trac Loc is fitted. Use dino 75W90 oil in the diffs unless you intend going off-road a lot.

ABS problems can come from a blown fuse or one of the wheel sensors is dirty or has a frayed cable going to it.

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2002 Export CRD 2.5 Sport

I couldn't be certain of the trac-loc, due to the fact that I am the second owner an the rear diff is rusty, so if there was a sticker, it probably fell off long ago. When I drained the rear, I checked to see if I was throwing any codes, and I got an 0501, which I assume was because there wa no fluid in the diff. I cleared it and it hasn't come back. I replaced the front wheel bearings a few months back, and the ABS sensor cables still look clean and undamaged. I will pop the rear sensor again and use sensor clean on it. If i add modifier, will the modifier 'hurt' even if I don't have trac-loc?

I'm pretty sure use of additive if not needed is harmless but am not positive.

However, as to whether on not you have trac-loc visit a Jeep dealer parts counter with your VIN and request a "build sheet", should be free, which will list all the stuff your vehicle came with.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

If you do have lsd, and put in oil w/o friction modifier, you won't break anything, just fyi, your lsd will behave as an opened difff.

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2005 kj CRD, samco, suncoast tc, provent, Kennedy lift pump, GDE ECO full torque, 2nd gen filter head, 245/70/16 a/t tires, mopar light bar, fumoto oil valve, OEM Skid Plates, ARB Front bumper and HD OME, tru cool LPD47391 40k GVW tranny cooler (stock cooler delete), FF Dynamics e-fan and shroud, rocker arms replaced, HDS2 190F thermostat.

Not even close. It will still work as an LSD, it may just shudder a bit in tight turns. Mobil 1 has the additive already in it.

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05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.

Sofar I still have speedometer and tachometer functioning...

One more symptom: I noticed that my fuel efficiency dropped drastically. Before it was sitting around 23mpg; it suddenly dropped to 18.3mpg...

So I decided to reset my MPG and now I'm getting 0.0 MPG. (Kinda funny) I ordered the rear axle sensor; stealer says it will be in tomorrow. Will let you know...

It is my impression from researching this topic that CONVENTIONAL and NOT synthetic oil is better suited for use in differentials.

Ive had this problem op. my abs, parking brake light and tone come on about a half mile down the road. I have dug into it at all. From earlier threads on here, I'm def leaning towards sensor or bad wire going to sensor. I did notice lastnight that I do have a brake line leaking at the front left wheel. But the lights have been coming on before that. Oh, and once to tone goes off, my odometer quits working. Sounds like that's what's happening to you.

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2005 Crd Silver Limited- arps, rockers, 7v etechno's, egr deleted, v6 airbox, metal cac's. Yeti's stage 2 tune. Euro TC, Ram tcm, pml transmission pan, facet lift pump

Friction modifier can actually go either way. The type used in the Trak Loc clutch type LSDs, as CATCRD pointed out, REDUCES friction and lengthens the life of the clutches. Without, you get "chirping" on tight turns and shorter clutch life.

For long life, go with a gear type like a Detroit TruTrac.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

So I don't have odometer function (reset tripmeter) and I did lose speedometer for a bit. I am hoping for the failed sensor, but I will check the wiring harness under the back seat. There was some mention of the wires being "too short" but there seems to be enough slack from the sensor to the cab protrusion.

Some times you have speed read out and some times you dont, abs is failed and the odometer is inop.. yup its the rear speed sensor or wiring.

I have been dealing with this read diff speed sensor issue for 3 or 4 years now. Initially the wiring failed that drops from the chassis to the sensor, and then it failed again. and then It was a bad sensor its self! I work on my own vehicles, I do what ever work I can but when it came to this issue I gave up because I couldn't tell what was causing the issue. I took the jeep to a very good local guy that has every dealer computer took for every OE, he has so much business that he doesn't even have a sign on his building! It seems crazy but a ton of the local dealerships come to him with drivability issues that they cannot diagnose. ( I witnessed a dealer tech picking up a car when I was there yesterday picking up the jeep for yet another rear diff speed sensor replacement, I think this is the third in about 2 years)

Mike, my super car computer wizard told me that when talking with some dealers that the part cost has come down 50% from when he bought it last and that the dealers said this is very common and a known issue. He also said that the part they replaced yesterday was yet another new revision and I hope it will last a little longer then 6 months this time!!

So If I were you I would take the loom off the wiring and check that first and if it looks good get a sensor. But the issue with mine was that the wire ended up looking good but it had an internal fracture. Mike had some good tools and said that this sensor is very low voltage and is difficult to diagnose with the average multimeter. I guess it has a pulse signal with only about 3 or maybe .3 amps sent to the sensor.

If you don't have the right tools or a good tech like Mike then good luck. I know most have not had as bad as an issue as I have had, could be that I live in an area where the roads are horrible and the constant jouncing is too much... who knows.

Also the speed sensor screws with all the readouts in the evic so the tire pressure and mileage read out along with temperature display will all be whacked out!!

If anyone in the SE MI area needs a good drivability guy let me know, you won't find better as he is fair with cost also!

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.

Thanks, Painemann. I can confirm that sensor replacement did not cure this problem. I will start tracing the harness back looking for a fault spot.....

Correction. She kicked in and I have sensor function. Guess we will see how long this lasts...