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Loud clunk when stopping hard and accelerating after the clunk

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jaredmwright, Apr 16, 2010.

  1. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Glad to hear that your car is back in service!

    I wonder if the hatch being open contributed to the death of your 12V battery?

    If you took photos and care to post your experience regarding replacing the half-shaft, I would be very interested. In particular, what was your method to remove the axle nut, and did you have any trouble pulling the old half-shaft from the transaxle? Did you use a slide hammer when removing the half-shaft?
     
  2. jaredmwright

    jaredmwright Junior Member

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    It is likely that the hatch being open contributed to my 12V battery issue as well. I will be ordering a new Optimus battery kit in the coming months.

    I didn't take photos of the CV shaft swap, but I did take photos of the brake pad shim problem I ran across which are included. The ears on both the driver and passenger side exhibited the same problem. Pictures are from the driver side.

    To remove the half-shaft axle nut, I simply used a small chisel and popped up the indentation and then backed off the nut. To remove the half-shaft from the transmission, I raised the car up on jacks as high as I could and then used a 3 foot pry bar. I tried using a 2 foot pry bar, but it snapped it in half! The 3 foot pry bar is substantially larger and stronger and with a little encouragement and quick but swift pushes on the pry bar it popped right out. The new one installed very easily compared to removing the existing one. I also replaced the transmission seal which was easy to remove, but difficult to get straight when installing the new one. Also, the original half-shaft had a deflector shield near the transmission on the end of the shaft. The replacement half-shaft did not have this piece and Toyota could not order it since it wasn't listed as a line item in their computer. If I was to do it again I would remove it from the original and install it on the replacement, but it isn't necessary. Overall the job should only take someone maybe an hour to complete with minimal experience.
     

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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Thanks for your comments. Did you use hand tools or an impact wrench to remove the axle nut? If the former, did you use 3/4" or 1/2" tools? (It seems to me that 1/2" would not be beefy enough.)

    I've got a large pry bar, so it's good to know that would potentially be effective in encouraging the half-shaft to disengage.
     
  4. 2009Prius

    2009Prius A Wimpy DIYer

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    What caused the loud clunk after all? The brakes or the missing nuts and bolts?
     
  5. jaredmwright

    jaredmwright Junior Member

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    If I wasn't clear, the cause was a missing transmission mount bolt and missing nut. On the transmission mount there are 5 mount points with studs/nuts. It was missing two of the five, and specifically the one bolt that was missing goes through the mount which extends from underneath the ABS/brake assembly behind the inverter. This is a crucial mount point since it restricts the transmission from torquing while accelerating/braking which was ultimately what was causing the "clunk" sound.
     
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  6. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    Axle nut and axle removal tools

    The best tool for removing Prius axle nuts is this one, Amazon.com: Schley (SCH65400) Toyota / Lexus 30mm Front Axle Lock Nut Remover Kit: Home Improvement it includes a custom chisel to perfectly "un-peen" the nut and a 30mm 12 point socket (6 point sockets won't work). You are supposed to buy new nuts at the dealer for re-assembly.

    If you don't have a big impact wrench Use a 1/2" breaker bar with a cheater pipe and have a helper press the brake pedal hard...that usually works. Unlike your bike pedals, both sides turn counterclockwise to remove.

    Note, don't just "spin off the nut" without un-peening it...you'll ruin the threads of the axle.

    If you are changing out axles, after you remove the lower ball joint etc to swing out the strut, this tool makes it easy to pop the axle out of the transmission side. Amazon.com: STECK 71410: Automotive

    And don't forget to drain tranny fluid via the 10mm "allen key" drain plug (other drain is coolant!) first unless you like a big mess on the floor!
     
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  7. Buckyswoff

    Buckyswoff New Member

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    I just had the same symptoms as the OP and after much much much much research. Like 3 weeks of head scratching. I figured out that my axle nut needed to be tightened. Boom. Problem solved.