Thump into reverse

[nicoleg6812]

Hi i have only noticed it a few times and doesnt happen all the time but my car seems to thump when i put it into reverse, has anyone else noticed this? Would have to admit its a little worrying when it does it, although does not effect it reversing or anything just a loud thud when put into reverse. I have tried pushing harder onto the break and not releasing the foot break right away and this does seem to make a difference occasionally. But would like to know if anyone else has had it happen?

[DJKOR]

May I direct you to this thread. Yes it says 'uphill' in it, but the symptom can be replicated on any surface. Does this sound like your issue?

Clunks into gear when car is uphill

the park gear has a bit of free movement in it, maybe about an inch of movement on the wheels either way, you can test this by parking on a flat surface, putting it in park (no footbrake) then getting out and pushing the car forwards untill it stops, then backwards, and you can see the free play that the park gear has.

when you are engaging the park gear and the footbrake on an incline, you aren't putting the footbrake in enough, and the only thing stopping your car from rolling is the "locking" action of the park gear. so the gears are all jammed together, that is why they clunk out/in to/from gear when on an incline, because it has to force the gears to "unlock"

suggest putting the footbrake on more firmly, i think 3 clicks is not enough, the normal is about 5-7 clicks (check car manual, should be written in there).

When in Park, the transmission engages a pin (or something like that) which holds the gears stationary, effectively locking the drive wheels. If you are on an incline and the weight of the car is on the "pin" there will be more friction on the pin as it disengages. Clunk.

Exactly what Zerko said with respect to a locking pin. It's not actually the effect of any form of gear jamming up as has also been mentioned but its the locking mechanism that all the weight is put on. If you would like to learn more, have a read here:

http://auto.howstuffworks.com/automatic-transmission11.htm

Anyways, in posts in the past as well, it has been said by others as well that the Aurion does tend to roll a little backwards after the park brake is applied. This is primarily due to the park brake design. My recommendation when parking on an incline would be as follows:

1) Come to a complete stop.

2) Put car in neutral

3) Engage park brake fully

4) Release normal brake slowly

5) Let car roll back/forward a little. If it rolls too much, you definitely have to get your park brake adjusted.

6) Once your foot is fully off the brake and your car is stopped completely by the park brake, put the shifter into Park.

If that doesn't describe your issue, then at what RPM is the engine sitting on when you put it into gear?

[Beep Beep]

Hi i have only noticed it a few times and doesnt happen all the time but my car seems to thump when i put it into reverse, has anyone else noticed this? Would have to admit its a little worrying when it does it, although does not effect it reversing or anything just a loud thud when put into reverse. I have tried pushing harder onto the break and not releasing the foot break right away and this does seem to make a difference occasionally. But would like to know if anyone else has had it happen?

Possible scenarios :-

1. You've had it in PARK and did not engage the Foot operated parking brake. Without the foot activated parking brake, the vehicle could've rolled forward or backward before the auto transmission stopped it from going further. Once it reaches this point, when you shift it out of PARK, you will notice additional resistance, followed by an audible "thump" noise as it disengages from PARK to R. This is simply because the weight of the vehicle is being held back by the Auto transmission in PARK and a lot of force is released when disengaged.

2. You shifted into reverse when the vehicle was still moving forwards. This may cause a sudden jerking as Reverse is engaged. You usually feel this rather than hear a thump, although a thump can sometimes be heard.

If it's none of the above, I would get it checked out at the next scheduled service. Or, if you're really worried, go get it checked out without further delay. Ideally you need to be able to replicate the issue in the presence of the mechanic.

I presume you have no fault warnings showing up on your dash either.

Edited November 4, 2010 by Beep Beep

[Amaro]

Or even when you start your car cold and its warming up i find putting reverse quickly while its still cold does the loud thud regardless of were its parked.

[DJKOR]

Or even when you start your car cold and its warming up i find putting reverse quickly while its still cold does the loud thud regardless of were its parked.

Hence my statement:

If that doesn't describe your issue, then at what RPM is the engine sitting on when you put it into gear?

[Silver-Aurion]

The OP's problem sounds pretty familiar. Till this day it's still clunking. But since I have had the car longer since when I first asked, I obviously just found ways to not let it clunk etc.

On an uphill, keep my foot firmly on the brake, engage foot brake, throw the car into P. Do take your foot off the brake until everything is in park and engaged!