Out for a drive last Saturday and then just about 3-4 miles from the house doing about 50 mph... I hear something hit the underside of the hood and I 'think' the sound of something hitting the road. Immediately, A/C goes from cold to hot. Battery Light comes on. Temp Gauge starts to rise. Immediately suspect serpentine belt failure; turn off radio and a/c. Roll down windows and kick heater on high, finish the drive home.

Problem really starts once I pull to a stop in my drive and shift to reverse to back into parking spot. Nothing. Shift back to drive. Nothing. Disco won't move. Try it twice more... then shut engine off due to heat. Pop the hood to help things cool down in the breeze, as suspected serpentine belt is off. Not shredded as suspected, but off the pulleys. Culprit? Tensioner pulley center cracked and belt slipped off. Replaced pulley, waiting on new belt (felt it best to just replace though not torn) but for now put old belt on.

Start Disco up, put in drive... won't move. Reverse... won't move. Check fluid level... just fine. Have someone shift car thru gear range while I check out transmission linkage for slippage... no problems. When started and shifting to drive or reverse, it sounds like something spinning but not catching. Double check that differential is in 'unlocked' high, won't move. Try 'unlocked' lock... wont move.

However, when I LOCK the differential: differential lock indicator lights up on console panel as expected and Disco will move in both drive and reverse. Great. Why isn't it moving when differential is unlocked in high or low? Drive shafts and universal joints seem fine.

Any ideas on what the issue could be or what simple solution (hopefully) is evading me? I'd rate my self as mid-level mechanic... sure not a pro! Mileage on my Disco is ust over 138K.

Originally posted on General Tech Help... senior member suggested I post on this forum for better response.

 

Only thing I can think of would be a blown diff or snapped axle that would cause that symptom but that seems really far fetched given it was fine before hand.

Reconfirm it won't move in unlocked again with a friend. Than have them put it in drive so you can look underneath and see if a driveshaft is spinning. Keep out from under the tires truck etc and have them ready to slam the brake instead of your house if it decides to be a Rover and start driving suddenly

If a shaft is just spinning you have something dead on that axle, be it a differential or axle.

Where in Texas are you by the way?

 

I am really curious as to what happened. Rovingtexas, did you figure anything out yet?

 

ArmyRover is on the right track. Have a helper put it in gear "unlocked" and watch the driveshafts(from next to the car, not under!!) if one spins, then that axle has either a bad half shaft or diff. If NEITHER spins, then you've got a grenaded center diff.

 

ArmyRover: I'm about 30 miles south of Dallas/Fort Worth. Had rain over the weekend so wasn't able to get under the Rover to check out your suggestion. Seems like when I was under before, diff unlocked, and transmission put into gear that shaft to front axle was spinning... but I don't remember if the rear was or not.

 

Currently in San Antonio for work for the next month. If you were close I was going to offer a hand

 

I would guess a cv joint or a drive shaft. take a look at the drive hubs out by the wheels too

 

ArmyRover: Appreciate the offer of assist, too bad you're not close enough to take you up on it. Did as you suggested and helper put it in gear with differential locked, neither driveshaft shins..

When the differential is unlocked (low or high) and put into gear... front driveshaft spins / rear driveshaft does not. I also hear a grinding sound coming from the front end when the differential is unlocked and put in Drive or Reverse. When differential is locked, no grinding sound... can drive forward / reverse. Not sure what a bad CV joint would look like, but nothing looks like it is out of place.

Llamasayswhat: You mention a bad half shaft? Given the new info, the spinning shaft is the bad one?

 

Ok so we know friend axle is the culprit so to check the diff. Not horrible to pull apart.

 

Youve either got a blown cv joint, broken axle half shaft, or broken diff, I would drain the differential fluid and check for metal. If there's metal there, odds are its the diff. If its clean, you'll have to pull the hubs off and check the CV joint.

I'm surprised you didnt hear anything leading up to this/when it let go