OK so I got a goofy question about the front axle. So with the truck in 2WD, the front driveshaft does not turn going down the road, that much we know. But, when the truck is rolling, the CV/axle shafts are obviously turning. But since the driveshaft isn't turning, this by default means the ring and pinion inside the housing is also not turning. So the axle shafts are just spinning freely between the spider gears inside the carrier.

So here's the theoretical quesion...if a ring and pinion were installed with the backlash less than perfect to point you'd have a whine or a roar caused by such, then theoretically this noise would not occur while driving in 2WD, correct?? Should be correct since they're not turing against each other but in fact sitting static.

Second question. If you had a limited slip carrier in the front axle, would this still remain true? Would the driveshaft not turn while driving in 2WD?? OR would the rolling axles through the clutches/action of the LS cause the whole carrier to turn and cause the drifeshaft to turn all the time as a result?

Yes, I'm bored thinking of stuff to ask?

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I actually do have a slight roar right around 20 mph that's gone by 25 mph and I can't pin it down. Doesn't sound like tires, but doesn't sound like a gear whine either; it's a roar) You can only hear it in the cab; can't be heard while listening outside the vehicle...I drove arond hanging out the door with the wife driving so I could listen...no apparent noise from underneath. If my theory is correct above, then it shouldn't be a bearing in the carrier anyways. Plus the pinion bearing and the wheel hubs are all new.

 

I would say that the driveshaft wouldnt spin. when the truck is in 2wd the passenger side axle shaft isnt even connected to the shaft that connects it to the carrier. the passenger side axle shaft is a 2 peice design.

but to be sure, put a peice of take connecting the driveshaft and the axle housing, put it in drive and see if it breaks. thats a easy way to tell if the drive shaft is spinning.

 

That wasn't part of the question...I know the driveshaft doesn't spin. That's been confirmed.


Ohhh, great point. I overlooked that fact.

 

so whats the question? if the drive shaft isnt spinning, then you know the ring and pinion isnt spinning either.

 

Well, re-read my post and should be easy to figure out; it says "So here's the theoretical question..." But yes, I guess I agree we answered that one by default! There was also a second question that started out "Second question..." I even started my very first paragraph with "So with the truck in 2WD, the front driveshaft does not turn going down the road, that much we know." Sorry str8t, I'm really not trying to be a smarta$$, just sayin

I told ya I was bored...plus trying to possibly figure out my roar.

 

spider gears dont freewheel in a "straight line" if they did there would be no way to apply power through them

 

Ohhh, another good point. Maybe that's why the axle shaft on the right side is disconnected in 2WD.

 

theres a guy with a red expedition on here, i cant remember his name but i think he has a LS up front, he could answer the question.