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I put a new set of agressive rough tires on my Dakota then after about 2 wks I noticed a funny noise,I checked under the hood and felt the pumpkin(barely warm) and scratched my head decided to check oil level in differential(almost completely out of oil) the seal was leaking,didnt notice because the oil was being threw up in the frame new seal installed now it goes zzit-brttt! when I LET OFF THE THROTTLE WHAT DO YOU THONK i’VE RUINED AND WHAT WILL IT COST?-kEVIN

I would replace the differential seal and then fill with fresh lubricant. The price should be under $50 and it’s well worth the price to find out.

Thanks,I did that ,still noisy-Kevin

The only way to know for sure would be to inspect the gears and the bearings. Since you have fixed the leak and it still makes noise I am suspecting you will have to overhaul the differential. If this is not a repair you have done before I would recommend having a shop do the work.

Thanks Steve,will have it evaluated-Kevin

cost varies greatly. if you pay a shop to replace diff assy than it will be expensive. if you get a used diff from junkyard and install it yourself it will be much cheaper. obviously

Yep found one on line ,whole shebang $ 990-Kevin

Sorry about the typos,keyboard is a little messed up and wife was razzing-Kevin

I pulled this off the Dodge forum. I remembered they use an additive if not added it makes noise.
“drain and refill of the correct rear axle lubricant and a 4 ounces of friction modifier. For Mopar LSD differentials the LSD additive (friction modifier) is part number 04318060AB.”

Well,Knfenimore I’ll probaly try that,Thanks-Kevin

The noise on coastdown would indicate a problem with the differential gears or one/both of the pinion bearings. It would be wise to get that checked out before it self destructs.

My guess is that you didn’t check the torque on the pinion before replacing the seal. It’s possible to you’ve tighten it too tight and damaged the bearing. There are two bearings, forward and aft. Forward bearing takes the load on power and aft bearing on compression.

I agree with @Rod Knox, pinion bearings most likely. Same thing happened to me a year ago. An independent rebuilt my axle, $1500. If you are handy, a used axle, as @knfeniore suggests, can be swapped out fairly easily. Especially easily if you can use air tools.

Boy Rod you have scared me-Kevin

When they go, they go ugly @Kevin.

Know what Guys? that thing is going to the shop pronto(then maybe to another owner before long)from what I gather this not all that uncommon-but to be truthful the reason I wasnt that prudent about checking the Diff was
A.Most all of of my other vehicles never gave Me this trouble
B.I had this rearend serviced at a pretty decent interval
C.I never seen it leaking
I know this is crazy-but do you think the synthetic oil had anything to do with early seal failure?-Kevin

A proper synthetic oil would not cause a problem in the rear end.

You might want to check out the axle bearings before tackling the pinion. When the oil level drops below the level of the pinion bearings it is no longer flooding the axle bearings and if there is any indication of damage to the pinion and axles a complete rear axle would begin to look like a good deal.

Thanks Rod,I’ll know next week,my crew chief is going to look Her over then-Kevin

Boy, won’t the well meaning advice around here turn sour when the find a dead mouse inside.

Dag,only thing in there was the greaseworms-Kevin