Manual gearbox selection

[passatpout]

Anyone else had trouble with manually selecting gears at times?

A few times lately, the car just hasn't shifted when I've done a manual change either through the stick or through the paddles. First couple of times it wouldn't change to 6th at 60km/h, but needed to get to about 67-68, then today it wouldn't downchange to 3rd while slowing down at about 70km/h..

It only had the 30,000km service about 3 weeks ago, and they advised everything on the gearbox was fine... even though I still think it has its rough moments..

[Rocket36]

How warm was it? It won't do high torque / high rev shifts (which both of yours were) when it hasn't warmed up. Why were you changing down to third at 70kph though? Were you racing? Because slowing down should be done by the brakes and engine revs should match the drive required at the speed you're doing. The engine should not be used to brake the car unless you have a brake emergency.

[Pana]

The engine should not be used to brake the car unless you have a brake emergency.

but but but, the DSG programmed to downshift when you apply the brakes going down the hill so you can use engine braking to keep your speed down rather than riding the brakes

[Rocket36]

The DSG will NEVER shift down to 3rd at 70kph to slow the car down.

[Pana]

The DSG will NEVER shift down to 3rd at 70kph to slow the car down.

I was responding to your comment about how engine braking should only be used in an emergency - engine braking is quite a normal thing to do in any car down a hill - saves you from cooking your brakes

and now that I think about it - I have had the DSG shift down to 3rd at about 60 or so down a steep hill. I then took my foot off the brake and it stayed in 3rd until the bottom - when I put my foot on the accelerator again to keep going, it then started shifting up to 6th as normal.

[Rocket36]

60 is not 70.

[Pana]

Passatpout - as yours is a diesel, changing to 3rd at 70 may be above the limit of what the gearbox considers a safe downchange - on the R36's - it won't change down unless the revs in the lower gear is below about 4200 (or thereabouts). Wouldn't know what the diesel change point is

[Swallowtail]

The DSG will NEVER shift down to 3rd at 70kph to slow the car down.

Yes it will.

It will change down if you are descending a hill with your foot on the brakes in the R36 as long as the resultant engine speed is less than 4500rpm. 70 is 4000ish in 3rd. It does it, I tried it.

Having said that, as Pana said that may be too high a speed in the 2.0 diesel for 3rd. Don't know, haven't got one!

As to "The engine should not be used to brake the car unless you have a brake emergency"... it is a perfectly valid technique for reducing heat in the brakes particularly on long descents. Would you advocate descending a hill in 5th or 6th? If not then you are using engine braking to some extent, regardless of whether or not you are on the footbrake at the same time.

[Rocket36]

whatever... im done arguing and im done providing advice. there's no point when all that seems to happen is people want to argue. it's pointless.

good luck with the gear box passatpout.

[drbass]

Much speculation and opinion but so far no facts.

passatpout, since I have essentially the same car as yours (including a slightly clunky DSG) I thought I'd give it a try.

First let's go through some thought experiments. This is all based on using the DSG in manual mode (NOT D or S).

50 km/h in 3rd gear is just about 2,200 rpm, give or take. 75 km/h will be about 3,300 rpm, give or take. That is well below the electronically controlled rev limit of 4,500 rpm for the 125 TDI. The engine spins quite happily to that limit when accelerating, and the DSG then automatically shifts up a gear. Not the most efficient way to accelerate but possible.

This morning, doing 80 km/h (GPS, not speedo) in 4th gear with warm engine and gearbox (I would like to think) I pulled back the DSG lever, and 3rd gear was engaged very smoothly thanks to the ECU matching engine revs to the speed perfectly. Ended up doing about 3,500 rpm. No sweat.

I have, and I hate to admit this, inadvertently selected 1st gear instead of 3rd when accelerating, and have seen in excess of 4,000 rpms.

I would think that, as long as the selection does not result in rpms exceeding the rev limit the DSG should simply obey and shift down, for whatever reason the driver chooses to do this.

Anyway, hope this helps.

Regards,
Michael

[passatpout]

Thanks all..

To clarify a few points, and to avert the disagreements...

First up, I've had it in 6th doing 60km/h within 500m of leaving home from a cold start. The occasions when it's played up have been when warm (while not at temperature, certainly showing around 70-80 degrees).

Second, the change point when downchanging is around 3000rpm. 40km/h in 3rd is roughly 1400rpm, so 2800rpm at 80, which would appear to be well within limits for a 4500rpm rev range.

What's happened, only a few times, is that the gear change points seem to go all over the place - auto changes suddenly happening at 3000-3200rpm, instead of 2000-2500rpm for similar throtlle settings, the box not responding to reasonable (if unusual) gear selections, either upchanging or downchanging.

It's happened both from the paddles and the tiptronic part of the gearbox.

Probably time to go back to the dealer and ask them about it... the software may have corrupted somewhere.. but also keep a bit of an eye on it again and try to be more observant..

[vanDub]

Anyone else had trouble with manually selecting gears at times?

A few times lately, the car just hasn't shifted when I've done a manual change either through the stick or through the paddles. First couple of times it wouldn't change to 6th at 60km/h, but needed to get to about 67-68,

I realise that passsatpout is talking about manual mode, but I have trouble accepting several posters on various threads claiming to have their DSG in 6th at 60 KPH without using manual mode. Under optimum (no acceleration) conditions in 'D' mode mine will change up to 5th at 66 indicated (62 real) and will never change to 6th until 77/78 indicated (72 real). At those change points the RPM is about 1600 after the change and I consider my gearbox behaves normally.

I cannot imagine the struggle any engine would have at a guestimated 1200 odd RPM for 60 KPH in 6th, especially when still cold 500 metres from start.

[Steve]

The engine should not be used to brake the car unless you have a brake emergency.

Whilst neither DSG car I have is diesel, neither manual mentions that the engine shouldn't be used for braking, and in fact the DSG kicks down to assist the brakes or roughly hold a speed whilst travelling down hill (without using brakes) more often than not when driven in "sport" mode. I don't know about "drive" as I don't use it when engine braking is likely to occur.

Furthermore, the DSG will allow any shift that won't damage either the gearbox or engine. Try downshifting at high revs. It won't happen. Depending on the delay between your input and an acceptable shift level find, the box may lag or may not shift at all. Either way, the shift won't occur outside safe levels. Also, the gearbox will automatically change up a gear if the driver won't and the rpm are computed to be damaging: for example, stick it in manual mode and floor it in first. You'll find the car changes to second. The gearbox won't allow a damaging speed/rev/acceleration combination to be present.

Are you basing your comment on speculation, or fact for this engine and gearbox combination? Neither either dealer I have purchased DSG equipped cars from (not that they are necessarily reliable sources) nor the service staff at two dealers and my preferred independent VW specialist mechanic have said that engine breaking is bad - and I've asked.

I'm honestly curious, as what you say is contradictory to trustworthy advice. Do you have inside information?

[Pana]

but I have trouble accepting several posters on various threads claiming to have their DSG in 6th at 60 KPH without using manual mode.

maybe other DSG's are calibrated differently, but under light throttle and once the engine and gearbox are warmed up, in D my R36 will happily potter around in 6th at 60km/h.

[Steve]

maybe other DSG's are calibrated differently, but under light throttle and once the engine and gearbox are warmed up, in D my R36 will happily potter around in 6th at 60km/h.

At that speed mine won't change from 5th to 6th without some intervention from me. Once there, though, it'll stay.