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I have an old Subaru with All Wheel Drive. I can feel in some circumstances the larger and more complex drivetrain "winding and unwinding" all those differentials and CV joints. It feels unpleasant, so I pause for a moment in Neutral before going to Park or Reverse, and then I do not feel the jerking and thumping that would otherwise happen. Is this a useful improvement?

Note that shifting from Neutral to Park goes through Reverse, but if I do it reasonably fast, Reverse does not engage. (In case it was not clear, this is an automatic transmission car. I just added the tag days after asking.) I also do this on other cars, not just the Subaru, and it similarly helps with the thumps and jerks of changing direction.

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  • I guess the drivetrain was designed to handle some large stresses, so the only wear and tear being saved is on my nerves. But, it costs me nothing to do this, I have to use the shift to change directions or park anyway. If it feels good, do it, right?
    – user15009
    Commented Apr 23, 2016 at 17:22

1 Answer 1

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Jerking and thumping when shifting through gears is an indication that you have bad either:

  • bad engine mounts
  • bad transmission mounts
  • bad differential mounts
  • bad axles
  • a combination or all of the above

Shifting into neutral does relieve the "tension", as you put it, but you need to care care of these issues. They can end up being costly.

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  • It doesn't happen while moving, it happens when I park, or back up. For example: I roll in to a space and shove it in to park: the drivetrain was pushing forward then it is just stopped. When I then back out, lots of creaking, bumping, moaning as everything undoes the stored tension in one direction and redoes it to back up. Solution? Put in neutral for a sec when I stop, then shift to Park. Then when backing up, no awkward noises. This is a 20 year old car with 200,000 miles, but it is a tank. (As befits something made by Fuji Heavy Industries: they make Battleships, too.)
    – user15009
    Commented Apr 22, 2016 at 13:16
  • Similar situation: park on a slight slope and let go of the brake pedal quickly: the car rolls until the parking pawl engages, then bounces back and forth with the stored momentum. Release the brake pedal slowly: it settles in place with no bouncing. "Better with 1, or 2?"
    – user15009
    Commented Apr 22, 2016 at 13:21
  • A 200,000 miles car must definitely need some if not all of the items I mentioned and more. Even tanks need maintenance.
    – race fever
    Commented Apr 22, 2016 at 20:12
  • Right, well I had it at the dealer recently for coolant flush and brake flush (and a failed sensor) and now it is going in for timing belt (and sway bar that came out at one end). This is a car, not an investment strategy.IIf they say something needs work, I will look in to it, but I could also... you know... buy a newer car some day. Repairs are cheaper than a car payment, or having it towed, but all good things come to an end. Anyway, does letting the forces out of the drivetrain help?
    – user15009
    Commented Apr 22, 2016 at 21:56
  • You are asking the wrong question. The fact that the "forces" need to be let out is a sign of advanced wear. :) I would start by checking the motor mounts and go from there. Best of luck!
    – race fever
    Commented Apr 22, 2016 at 22:16

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