What exactly happens in "Park" on the DSG

[susi]

Situation:

 

Sometimes when reversing out of a warm garage, it feels like the brake calipers are somehow "stuck on". When I engage reverse and apply some throttle pedal, there is a small "dung" before the car starts to roll.

This evening, leaving work, it was about -17°C and when I tried to reverse it felt like the brakes were frozen on to the discs. It took quite a lot of throttle pedal before there was a bang and the car started to move. It wasn't a small bang either...

 

We don't use handbrakes here during the winter (the normal SOP is to park in gear rather than neutral). This usually avoids the problem. But does anyone know what might be causing this problem? Does the "Park" position also engage brakes? Unfortunately it is not possible to remove the key unless the lever is placed in Park, so I'm at loss for a solution.

 

Briskodians (especially those in cold places) - Help!

[Ootohere]

Park engages a 'Pawl' in the gearbox and locks it.

& the car can only start in 'P' below -10*oC & not in 'N' if you leave it in 'N'.

 

Well in a Fabia, that is the story.

Edited 13 January, 2015 by goneoffSKi

[JoseDB]

I have found if you leave our foot on the brake when the engine turns off it seems to leave the system charged (and so brakes on). Be sure to release the brake pedal before turning the engine off.

[Smeghead]

Susi, how quickly are you trying to move off after putting the lever in R?  I've found the gearbox is a little slow to engage gear (about 1 second - my first Auto in 30 years so maybe the norm) and if you give it some throttle it comes in with a jolt as the clutch bites.

 

Add to that the 4WD Haldex and you might well have a bigger clunk.

 

I've also noticed after washing the car, the brakes do seem to rust up enough to stick which also does what you describe.  I would guess in a garage that's less likely unless the car was wet when parked and rusted a little before drying out.  Easy to check as the disks will be orange with light rust on them.

[pipsyp]

As per goneoffSKI's post. DSG have a park pawl (basically a huge bolt) that gets mechanically pushed through the differential effectively locking the gearbox. It basically mimics park on a regular auto box and you can in most cases probably get away with leaving the car in park without the handbrake on; however id there is much strain being placed on the mechanicals (i.e is parked on a steep incline, the parking pawl being the only thing preventing the car from moving) long term I cant see this doing the DSG box a whole lot of good. I also gather it is possible for the pawl to break, in which case you could end up with a runaway car.

The noise you are getting could well be brake binding or because the internals of the gearbox is so cold the pawl disengaging is making a bit of a racket. The pawl actually making noise engaging in park or disengaging when put into gear is however completely normal.

[cl coupe]

I put the car in R and leave the car to start moving, only once it is moving do I put power in, seems to stop any noises.

[Nookiebear]

I put the car in R and leave the car to start moving, only once it is moving do I put power in, seems to stop any noises.

+1 on this!

[susi]

Thanks very much for the helpful replies 

 

I think it could be Jose's comment about having my foot on the brake when keying off, will now try keying off without foot on brake..

 

I usually engage R and then wait for it to move itself. Yesterday when it was cold, I engaged R and waited, nothing happened, I thought I might have made a mistake and missed R, so I went back to P for a few seconds and then back to R, again nothing, even after a few seconds. Only after some throttle pedal did the car move. It really is very odd.

 

Luckily all my parking is on flat and level surfaces, so P only should be ok.

[conn]

As far as I know and I was highly suggested by my dealer - if you stop the car for 'P' you should engage handbrake, then move the lever to position 'P' (it does not really matter which you do first before releasing normal brakes). This way there will be no stress on the bolt, which is locks the gearbox. However on even ground there is no need for handbrake.

 

On very steep parking I have been suggested to stop the car, move to 'N', apply handbrake, release normal brakes (this way car is 100% relying on the handbrake), apply normal brake, move to 'P', stop the engine. This way there will be no stress on the on the bolt.

 

For notes I am using handbrake all the time - even on my manual I usually stayed in neutral and only applyed handbrake, unless there was some degree of steepness (then applyed first gear, but usually handbrake hold the car by it self)... If something is mean to be used on the car, use it - this way you can be sure it works. If it does not work any more - it will not be a bad surprise or something.

[Timpel]

This banging noise when start moving comes from brake pads which are stick to the disk, becose when driving water and moisture get stuck on pads and disks, and when you stop and lets say don't drive for couple or car stays outside overnight where its cold the water and moisture will freeze and froze the pads to the disk. Happens here all the time. I usually rock or  push car alittle bit back and forth to get rid of it. Otherwise when doing it with driving back or forward you might damage something. You never know. But its quite common here on your south In Estonia.

[susi]

Timpel, are you saying that this happens to you in cold conditions, even when you don't use the handbrake?

[KiDr]

Timpel, are you saying that this happens to you in cold conditions, even when you don't use the handbrake?

This happens to me all the time now and i do not use hand-break. My car stays in the garage over night and i think moisture and dirt that gets between break pads and disks dries out over night and securely glues them together:) I always apply break before switching off the engine. Will try to release it before, to see if it makes any difference.

[ajw1100]

As far as I know and I was highly suggested by my dealer - if you stop the car for 'P' you should engage handbrake, then move the lever to position 'P' (it does not really matter which you do first before releasing normal brakes). This way there will be no stress on the bolt, which is locks the gearbox. However on even ground there is no need for handbrake.

 

On very steep parking I have been suggested to stop the car, move to 'N', apply handbrake, release normal brakes (this way car is 100% relying on the handbrake), apply normal brake, move to 'P', stop the engine. This way there will be no stress on the on the bolt.

 

For notes I am using handbrake all the time - even on my manual I usually stayed in neutral and only applyed handbrake, unless there was some degree of steepness (then applyed first gear, but usually handbrake hold the car by it self)... If something is mean to be used on the car, use it - this way you can be sure it works. If it does not work any more - it will not be a bad surprise or something.

 

+1

 

I have always; 1.  applied the handbrake, 2. released the foot brake and then 3. engaged 'P' so no load is imposed on the gearbox.

[DGW]

The first link below has diagrams at page 22 showing how the parking lock works on the 6-speed DSG gearbox. For those with a 7-speed DSG, look at pages 26 and 27 in the second link.

http://www.volkspage.net/technik/ssp/ssp/SSP_308.pdf

http://forum.quattroruote.it/posts/downloadAttach/12858.page

[Minimoke]

The first link below has diagrams at page 22 showing how the parking lock works on the 6-speed DSG gearbox. For those with a 7-speed DSG, look at pages 26 and 27 in the second link.

http://www.volkspage.net/technik/ssp/ssp/SSP_308.pdf

http://forum.quattroruote.it/posts/downloadAttach/12858.page

Excellent link DGW. Only problem is its doing my head in trying to follow precisely how this actually works. Old age I suppose.

[fatzy]

Situation:

 

Sometimes when reversing out of a warm garage, it feels like the brake calipers are somehow "stuck on". When I engage reverse and apply some throttle pedal, there is a small "dung" before the car starts to roll.

This evening, leaving work, it was about -17°C and when I tried to reverse it felt like the brakes were frozen on to the discs. It took quite a lot of throttle pedal before there was a bang and the car started to move. It wasn't a small bang either...

 

We don't use handbrakes here during the winter (the normal SOP is to park in gear rather than neutral). This usually avoids the problem. But does anyone know what might be causing this problem? Does the "Park" position also engage brakes? Unfortunately it is not possible to remove the key unless the lever is placed in Park, so I'm at loss for a solution.

 

Briskodians (especially those in cold places) - Help!

I haven't studied the locking mechanism of the DSG, but in my mind the dong you hear are the brake pads which is forced to let go from the discs. It happens also in warm weather, as well as cold.

I assume it is the "HILL HOLD" function that has pressurized the brakes when you stop in the garage. This is most noticeable with a DSG because the gearbox/engine always has a positive drag when in gear unless brake pedal is pressed, and all are equipped with "HILL HOLD". The same will happen if hand brake is applied, lets say over night.

I suspect that the brakes are warmer than the ambient temperature when you park the car, and cools down with a different rate. The steel first and secondly the pads. This must create a static binding so that the pads sticks to the disks until you force them to let go by starting to drive off.

[DGW]

Hill hold shouldn't pressurise the brakes in a garage unless of course the floor has a slope of more than 5 degrees...

http://new.skoda-auto.com/en/models/Pages/HotspotDetail.aspx?HotspotName=C18%20-%20Asistent%20rozjezdu%20do%20kopce%20%5BFabia%2CRoomster%2C%20Octavia%2C%20Yeti%2C%20Superb%5D&WebID=19e2ce5d-c6b0-414b-9be6-113388595538&Page=technology

[Exeterj]

This banging noise when start moving comes from brake pads which are stick to the disk, becose when driving water and moisture get stuck on pads and disks, and when you stop and lets say don't drive for couple or car stays outside overnight where its cold the water and moisture will freeze and froze the pads to the disk. Happens here all the time. I usually rock or  push car alittle bit back and forth to get rid of it. Otherwise when doing it with driving back or forward you might damage something. You never know. But its quite common here on your south In Estonia.

Agree with this - my vrs does it, but my old manual mondeo and focus before that used to also, just pads releasing from disks.

[philbes]

I overcome the delay when engaging reverse, after the car has been standing for some time, by selecting first and moving forward a few inches. I can then select reverse and move immediately on a very light throttle with no clunks etc. At least I do that if I remember when parking in my drive to leave sufficient room between the wall and the car. When possible I reverse into my parking space but that is not possible if there are two other cars in the drive.

[JoseDB]

I wonder also if floating callipers play a part? Not sure of the Octy has them, but on my S1 at least going fwd/bwd 6 inches at a time would result in a clunk on every braking event as the calliper slides with the pad on initial contact for a few millimetres.

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[fatzy]

Ok, Elimination method:

- P-position of DSG is an mechanical lock inside the gearbox and has nothing to do with the brakes.

- Hill Hold will not keep brakes applied when stopping in a flat garage.

- It appears when parking brake has been applied "over night/day".

- It is not directly related to temperature/freezing, as "clong" appears above 0 cels. also.

- Floating calipers has only micromillimeter of play so it can't make such a noise (how would everyday driving sounded like then?).

My conclusion:

The brakes are warmer than the ambient temperature when you park the car, and the brake components cools down with a different rate. The steel first and secondly the pads. With hand brake applied, this must create a static binding so that the pads sticks to the disks until you force them to let go by starting to drive off. Water and/or surface rust on discs + application time may play a role in the force of the static binding.

[JoseDB]

The callipers thing is related to change of direction, so they only make (a very audible) clunk - travel distance is irrelevant - when you are manoeuvring fwd and bwd, which technically you are when reversing out of the garage having come to a stop on the brake fwd the evening before, then as it is DSG you drag the calliper to the other end of its mount as you reverse - in a manual it wouldn't happen as you would not drag the brake (in a manual the clunk would come when you brake after reversing).

Still don't know if the brakes are even floating callipers though. It's a very common complaint on hundreds of cars that do have them tho. It sounds very disconcerting!

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[fatzy]

What Susi refers to do not relate to floating calipers or not, nor DSG/manual. I have the same experience with both manual and DSG's as Susi described. And it has nothing to do with change of direction. It is REAR brake pads that is stuck to the disks and the loud bang occures ONCE, as you set off after being parked for some time. Not always, but occasionally.

Of course there are movement in brake parts, but mainly in the pads related to theirs fixation pins. The calipers floating movement is based on micromillimeter play unless worn extensively.

I stick to my theory as a solution to tread starters phenomenon.

[Gabbo]

I stick to my theory as a solution to tread starters phenomenon.

 

+1

I have the same thing with my manual car, parked overnight in a warm garage with the handbrake off (1st gear engaged).

When its been wet outside (like last Friday) something at the rear sticks & there is a "crack" as they are freed when you drive off.

The disks show a light rust & braking afterwards for the first few times gives a light grinding sound then everything is fine.

[conn]

Felt the crack on the back this weekend - parked outside for two days. Definitely pads stuck the the disc.