Is it healthy for an automatic to?????????

[noogieman]

Sometimes when I drive my C43 AMG I don't use the brakes, instead I use my automatic stick to downshift and slowing down the speed by engine,s braking!

Like when you down shift a manual gearbox and the engine is braking and then slowing down the speed without stepping on the brakepedal!

Is this dangerous to do on an automatic transmission?
Downshifting 1 or 2 gears within a range of (10-30 km/h) down is this hazardous for an automatic?

Sometimes I miss driving a manual stick, so the downshifts for extra power when speeding or slowing down speed I use to downshift a gear or 2!

If I use the shifter this way, am I going to **** up the transmission or not?
We all know that these transmissions are weak! (7.22631)

Sorry about the corny explanation!

 

[renault12ts]

No. That's what it's designed for. Kick down does it a lot more aggressively if you think about it.

 

[Lugy]

It's something I do very often, if the car thinks it'll damage something it won't allow the shift!

 

[clk208]

My driving instructor (ex mechanic) always used to say the advice with modern cars (he was talking about manual transmissions but I assume similar applies with an auto) was to use the brakes first and foremost and only use engine braking as a very last resort.

His rationale was that modern cars are no longer over-engineered and have lightweight bits built just strong enough to do the job - so using the gears to slow down was a recipe for disaster for a transmission.

Not sure how true this is, and we were in a ford fiesta but the lack of over-engineering in modern mercs seems to ring true to a certain extent!

 

[C43AMG]

Brakes are much cheaper to replace than gearboxes.

 

[grober]

Brakes are much cheaper to replace than gearboxes.

As C43 says brake pads are much more accessible then automatic gearbox clutch packs or brake bands!!

 

[noogieman]

Thanks for the update guys.
So in the long run this bad habit might destroy an automatic transmission?
I guess I have to use the brakes more often then!

I always downshift a gear or 2 when I come to an uphill bridge or just an uphill road so I don't stress my transmission to work on D-mode, instead I use the 3rd or 4th gear manually and the transmission knows which gear to use when going uphills.
Thanx

 

[PJayUK]

We all know that these transmissions are weak! (7.22631)

Are they?

I thought that the 722.6 boxes were very strong as far as autoboxes are concerned. Clearly like anything if its abused or poorly maintained then its lifespan will be impacted but compared to other auto's I was under the impression that its robust.

 

[Gridlock]

I've had a new gearbox (before my ownership), timk has, I think there's another one on here that has too. So that's 1% of UK sales already...

 

[DRBC43AMG]

I have had an automatic as one of my cars since 1979. I use the box like a manual when doing some spirited driving (manual up and down shifts but always shifting up before the revs red line), but apart from in very slow moving traffic in order to do an gentle slow down without the brakes, I ALWAYS apply my brakes first before downshifting manually. Never had any gearbox problems of any sort due to this. With my C43 I find the box much more intelligent than the other auto boxes I've had and it downshifts automatically without touching the lever at all.

 

[Colin_b]

My driving instructor (ex mechanic) always used to say the advice with modern cars (he was talking about manual transmissions but I assume similar applies with an auto) was to use the brakes first and foremost and only use engine braking as a very last resort.

His rationale was that modern cars are no longer over-engineered and have lightweight bits built just strong enough to do the job - so using the gears to slow down was a recipe for disaster for a transmission.

Not sure how true this is, and we were in a ford fiesta but the lack of over-engineering in modern mercs seems to ring true to a certain extent!

I think your instructor was right, though probably for another reason. Braking via the foot brake brakes all 4 wheels, downshift just the rears (assuming a 'proper' MB) which could lead to instability. Or so I was told, and it seems reasonable.

 

[Gridlock]

Decelerating without braking is manoeuvring without signalling - I'd guess this is why it's not taught any more.

 

[wemorgan]

My wife's Smart car is odd in more ways than one. It has an automatic-manual gearbox. This equates to having only a brake and accelerator pedal plus a stick to shift the gears up or down. When accelerating you have to push the stick forward for the gear to go up, since this is not automated. But when braking the anti-stall will change gears down for you. But if you allow this to happen it will invariably be in the wrong gear at the wrong time, or at best, the right gear but at the wrong time. So to manage this, whilst braking I also use the gear selector to manually change down gears. This works quite well at roundabouts when needing to take advantage of small gaps in the traffic. I like to think most of the braking is being done by the brakes, but at times I do feel the car lurch as I shift down. It's all part of the Smart experience

 

[martin_a]

I find it strange that the car doesn't do it automatically....

I had a Mitsubishi FTO a car released in 1994 that would automatically downshift for you (if in D) when the car sensed a gradient and prolongued use of the brake to hold the cars speed on a hill.

Cracking gearbox that.

m.

 

[johnsco]

I use engine-transmission braking during snow or icy weather.
The principal braking effort is on your front wheels.
With an automatic, it is easy to end up with the front wheels locked (or ABS-ing), while the rear wheels are still turning.
Careful use of down-shift while descending an icy hill can give you better control compared with just using the brakes.

Other than that, I tend to the view that:
"Brakes are cheaper to wear out than transmissions"

 

[MrMotul]

Up untill about 6 years ago, I used to buy Fords from one of their test centres in Dortmund, these were cars that had something or other tested for sometimes tens of thousands of hours, or tens of thousands of miles, maybe even more than that? Any parts that were tested, or others that could wear due to the testing, were then replaced, then the cars were sold by means of a bid sheet. The reason I am writing this is, I think that anything that any of us has ever done to our cars, for instance, changing down the gears to slow down without using brakes has probably also been done by test centres many more times and done much harsher than we could ever do, over and over again! I had only a slight insiders view about what type of testing goes on to all parts of a vehicle, I can only imagine the amount of testing that goes into an uprated car before it goes on sale to the public. I just bought a 2001, S210 E55 done 144,000 miles and I use the gearbox all the time to slow down, but I will always be aware that anything can go wrong at anytime, THEY ARE MAN MADE

 

[johnsco]

If you put my E300TD in "speed limiter" mode, then the transmission will shift down one or two ratios while descending a steep hill.
The car senses that it is going too fast and down-shifts to regain control of the set speed limit.
CLEVER !!

 

[Chrishazle]

Training methods have changed over the years. I learnt to drive in the late 1960's on a manual car, and was taught to always try to be in the correct gear for the conditions - changing down approaching junctions and roundabouts, even for some bends in the road! Yet my children, who learnt to drive in the late 1990's and mid 2000's were basically taught "go pedal, stop pedal" method - and my daughter was told off by her driving instructor for using the gearbox the way I taught her when taking her out to practice between lessons. ISTR he said she'd fail her driving test if she continued driving that way!
One thing I like about both my cars is that I have not only very good brakes with ABS, but also enough power to accelerate away from a problem - thus 2 options most of the time. If you are not in the correct gear you loose one of those options! OK, an automatic should get you down to an appropriate gear as you decelerate - but not all boxes do. I nearly got T-boned pulling onto a roundabout test driving a BMW M3 Evo with the steptronic box (admittedly 12 years ago) because I had it in manual mode and had stopped in 4th - it did not automatically change down the way my 968 tip does in manual mode!
So - I do not agree with the 2 pedal method, and use the tip function on the C270 to change down approaching junctions, roundabouts etc.

 

[grober]

I would distinguish between being in the correct gear for any road situation and actually "braking" the car using the transmission. It's that crucial moment when the drag of the slowly rotating engine with closed throttle is linked to the faster speed of the final drive. That extra kinetic energy has to go somewhere. Once the lower gear is "selected" and engine and road wheels linked then engine braking say over a long descent should have no ill effects on the transmission.

 

[noogieman]

Good evening all chaps.
Thanks for the lessons!
I guess i have not done any harm to my transmission by changing gear
(1 gear or 2 depending of which speed I was driving) and then use the engine as a brake instead of my regular brakes?

I change my trans oil regularly when needed, transmission works fine!

one thing I have noticed though, is that when I enter a low speed area like school zones and the speed is restricted to 20 mph, my transmission makes like a small twitch or a TICK when downshifting, it is noticeble when it downshifts to a lower gear!
Maybe lurching is the correct word?????????
No strange sound or anything just like when your'e thrown forward when braking to hard!
This is what it feels like when Í enter a school zone and the trans downshifts to a lower gear in D-mode!
I don't think this is something wrong maybe the trans is designed this way?

(I mean a tick like a muscle spasm, this is what it feels like when the trans downshifts to a lower gear when driving on low speed area)

Anyway thanks for the inputs guys!