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

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...

I believe the 722.6 5 speed box fitted to the C43 is more prone to failure because of the bespoke AMG software which was installed on the trasmission ecu.

Also these gearboxes get eaten up all the time because they have to handle so much power.

Obviously i would also think how the car is driven is a factor worth considering, being am AMG maybe the previous owner use to drive it quite hard a lot of the time, which will in turn lead to the gearbox suffering. Some people still have C43's with original gearboxes without issues.
 
I believe the 722.6 5 speed box fitted to the C43 is more prone to failure because of the bespoke AMG software which was installed on the trasmission ecu.

Also these gearboxes get eaten up all the time because they have to handle so much power.

Obviously i would also think how the car is driven is a factor worth considering, being am AMG maybe the previous owner use to drive it quite hard a lot of the time, which will in turn lead to the gearbox suffering. Some people still have C43's with original gearboxes without issues.

I never drive my car recklessly!
I always wait until it is in correct work temperature.
After the warm up I can floor it.
Pedal to da metal.
It is always important to get the car fully warmed up for about 15-20 minutes of constant driving a few miles.
I always drive a 20 km long route to get my car fully warmed up, then I can play!
 
I think I may of missed the point of this thread, but risking ridicule why don't you just use the brake? I can understand taking a lower gear to give greater flexibility or on a very steep down hill descent, equally so to avoid braking in hazardous conditions, but generally the old adage "brakes to slow, gears to go" still holds true.
More so if you are pressing on.
 
I think I may of missed the point of this thread, but risking ridicule why don't you just use the brake? I can understand taking a lower gear to give greater flexibility or on a very steep down hill descent, equally so to avoid braking in hazardous conditions, but generally the old adage "brakes to slow, gears to go" still holds true.
More so if you are pressing on.

I understand where you are coming from, but I think its to do with the fact that a lot of us are racing drivers at heart and our tracks are the main roads, changing gear or using the brakes to stop will have a similar effect on the car (it will stop eventually) but methinks its the "Boy Racer" in us and as long as everyone stays safe and the only thing we hurt is our pockets, everyone's happy, or at least, nearly everyone :rolleyes:
 
I think I may of missed the point of this thread, but risking ridicule why don't you just use the brake? I can understand taking a lower gear to give greater flexibility or on a very steep down hill descent, equally so to avoid braking in hazardous conditions, but generally the old adage "brakes to slow, gears to go" still holds true.
More so if you are pressing on.

my question was is it dangerous for the transmission if I downshift a gear or 2 to lower the speed instead of using my brakes?

When you let go of the accelerator you cut the fuel right?
It must be the same when you brake with the engine, no foot on the gaspedal?
Am I correct?
 
my question was is it dangerous for the transmission if I downshift a gear or 2 to lower the speed instead of using my brakes?

When you let go of the accelerator you cut the fuel right?
It must be the same when you brake with the engine, no foot on the gaspedal?
Am I correct?

As I said I think I probably missed the point of the thread
 
I never drive my car recklessly!
I always wait until it is in correct work temperature.
After the warm up I can floor it.
Pedal to da metal.
It is always important to get the car fully warmed up for about 15-20 minutes of constant driving a few miles.
I always drive a 20 km long route to get my car fully warmed up, then I can play!

Don't worry about it...
In most cases the auto trans of the Merc will not manually go into too low of a gear until it reaches a certain speed.

I've owned my 1988 300CE since new and always manually downshift the 722.3..No problem now even with twin turbos.

Do it with my C43, G55K and of course my CLK63 Black Series seems to handle 507HP with the 7 speed auto in full manual mode !!!

Auto trans is just that...upshifts and downshifts when left to its own devices...
If you manually up/down shift just stay in a range that won't over rev the engine...no different then shift points with a manual trans.

The C6 Corvette automatic actually "blips" the throttle when you manually downshift to match engine speed....

Better to downshift the auto manually then to hit kickdown to go to a lower gear...less drastic !!!:thumb:
 
Brakes are much cheaper to replace than gearboxes.

Was pretty much how Jackie Stewart put it 40 years ago.

No race driver ever downshifted before braking. It is bad driving. Track or road.
 
Left foot braking with a blip on the downshift! Super smooth. Turbo primed and boosting before the brakes are fully released for corner exit.

We don't hop on one leg when walking. Why not use both feet when driving an auto or AMT?
 
Was pretty much how Jackie Stewart put it 40 years ago.

No race driver ever downshifted before braking. It is bad driving. Track or road.

With a manual transmission, when braking and downshifting prior to a corner, you must brake in a straight line while simultaneously clutching the car, revving the engine to match the speed of the drive wheels, putting the car into a lower gear and then releasing the clutch without upsetting the tire contact patches and suspension in the process

Of course this technique has nothing to do with the thread starters query...
With an auto trans you're not trying to match engine speed and synch the lower gear as there are no gears to synch..just fluids and clutches to engage..
No harm will come to the auto trans to downshift from drive to third to slow the vehicle down without braking at the same time....:thumb:
 
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I really enjoy the automatic drive when I take my 320 to Scotland, Breaking is hot and the kickdown is instant.
I would always break down rather than drop
 
I really enjoy the automatic drive when I take my 320 to Scotland, Breaking is hot and the kickdown is instant.
I would always break down rather than drop

I do hope that's 'brake' and not 'break' you are referring to! lol :D
 
With a manual transmission, when braking and downshifting prior to a corner, you must brake in a straight line while simultaneously clutching the car, revving the engine to match the speed of the drive wheels, putting the car into a lower gear and then releasing the clutch without upsetting the tire contact patches and suspension in the process

Of course this technique has nothing to do with the thread starters query...
With an auto trans you're not trying to match engine speed and synch the lower gear as there are no gears to synch..just fluids and clutches to engage..
No harm will come to the auto trans to downshift from drive to third to slow the vehicle down without braking at the same time....:thumb:


Thnx for the interesting lessons.
I know a little more about automatic transmissions now.
Which means I don't have to worry about the way I used to drive before!
No harm will come to my transmission that way.
I might use my brakes a little more so the pistons on my calipers don't get jammed when used seldom!

Thanks for all the info guys.:thumb:
 
Then don't ask it to do what the brakes are there to do.

Sorry, I don't understand what you're saying!
You mean I shouldn't brake with the transmission instead I should use the footbrake more often?



C43 transmission is weak from what I've heard and been reading on other forums.
How come then this 722.631 transmission was in V8 CL cars if it can't handle the tourqe?

E55 trans seems to be tougher, this trans has another parts number than C43 722.631 transmission, but they are still almost the same?
Are there weaker parts in C43 transmission?
 
The brakes are for stopping/slowing the car with. Ideally, with a perfectly executed downshift no engine braking should be present. In reality a modicum of engine braking is useful to 'trim' the handling, but in no way should the bulk of braking be via the engine and transmission.
The inevitable result will be accelerated wear of all components concerned throughout the drivetrain including the premature degradation of all oils.
The brakes as well as being vastly more powerful, operate on all 4 wheels, have inbuilt safety in the form of ABS and are designed as consumable, allowing use to the point of destruction with replacement a routine task, not a rebuild.

It is your choice how you drive your car and you will probably never experience the accelerated wear within your tenure, but in my opinion to drive in that manner is just bad driving and not without danger either. If you suddenly have to apply the brakes or swerve while utilising a high degree of engine braking, the resulting instability will either have to be countered by you the driver, or the ESP system, both of which will take up road space you may not have at your disposal.

The classical method, brake, downshift, power on, apart from being safer, is also an altogether more positive and rewarding way of driving. Frankly, anything less is just sloppy.

Click, click - the sound of me stepping off my soapbox...
 
It is in your opinion "bad driving". That's just a little arrogant. By all means discuss the various methods we all use, but don't accuse others of bad driving because you do it a different way.

I have always used engine braking and brakes...why not? Engine braking does not have to be violent, but by matching engine speed and then easing off you will get the effect you want without undue wear to the trans.. I presume you use kick down? Now, that is a violent and stressful action on the gearbox, and a very satisfying thing. On the other hand you can use the tip. (sic) function to drop a gear or two for the same reason, just as in engine braking...what's the difference?
 
C43 transmission is weak from what I've heard and been reading on other forums.
How come then this 722.631 transmission was in V8 CL cars if it can't handle the tourqe?

E55 trans seems to be tougher, this trans has another parts number than C43 722.631 transmission, but they are still almost the same?
Are there weaker parts in C43 transmission?

I've heard 2 stories; one that transmission fluid leaks past the seal into the ECU housing and you find yourself in 2nd at 90mph, another that the AMG software is somehow not all that good.

I'm just some guy on the internet though, would be keen to hear anything concrete from someone who Knows ;)
 

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