Mercury Mountaineer 2003 Transfer Case Is Viscous Coupler Problem?

I have a Mercury Mountaineer 2003 with the 4.6L engine with automatic transmission and 4WD.Question:This vehicle has 125000 miles and has been used to pull a 25' trailer over the last 5 summers.  When turning the vehicle on the asphalt it feels like the front tires are pawing, at first I thought that maybe it was the rear differential.  A few days ago it was stuck in the snow and the rear end was not locked up.  I have inspected both the front and rear differential with the covers off and all looks good.  I suspect the viscous clutch is the issue.Answer:You have the BW4410 transfer case we agree based on your description the viscous coupler is defective and needs to be replaced.  While you have the unit apart we suggest you check the drive chain for excessive wear or stretch.  The parts you will need are:

• Viscous Coupler part number MWT4400-625-001 your cost is $329.00

• Seal kit your cost $15.00 plus S&H.

Make sure all of the tires are the same diameter and pressure, this is the #1 cause of viscous coupler failure.For information on replacement transfer cases see our site.