QuestionI have a 4.6 HSE with 115,000 miles on the clock. I recently replaced a failing
rear differential, and was told that the axles should probably be replaced at
the same time (I had been noticing a clunk when shifting from forward to
reverse, and was told that the splines connecting the axles to the diff must
have been loose) I am about to replace the rear axles this week. Today while
listening when changing from forward to reverse I noticed what I believe to
be the same clunk coming from the front of the car. Is this a sign of front
differential failure? Should I be replacing the differential and the axles on the
front now too? I have also noticed a 'grabbing' feel when decelerating, like
the transmission is braking. Could this be related to an extra (mild) vibration
I feel when accelerating? Or could this be the torque convertor causing
troubles? A lot of questions/problems I know, but thanks in advance for your
help. On a side note.......What grade of oil would you recomment (I have been
using 20-50W) It gets incredibly hot here and also very cold in winter, and is
it doing any damage filling with regular unleaded instead of premium?
Regards,
Simon
AnswerChanging the differential on its own should be sufficient. I have never had any spline wear. If the halfshafts are broken, they would be snapped. I do not think you need to chenge your front or rear axles.
The clunking and the vibration when accelerating indicate that it may need a universal joint on a drive shaft (prop shaft. This is normally caused by the viscous coupling in the transfer case locking up. This is normally felt on tight turns, you feel the car grabbing on a hard turn, e.g. a u-turn.
You are using the correct oil for the vehicle.
