Everything You Need To Know About

7 SPEED S-TRONIC AUTOMATIC GEARBOXES

S-Tronic automatic gearboxes MILTA Technology

Everything You Need To Know About

7 SPEED S-TRONIC AUTOMATIC GEARBOXES

S-Tronic automatic gearboxes MILTA Technology
S-Tronic automatic gearboxes MILTA Technology

WHAT IS 7 SPEED S-TRONIC?

The dual-clutch transmission, also known as the Direct Shift Gearbox (DSG) or twin-clutch transmission,
is an automated transmission that can change gears faster than any other geared transmission.

Dual clutch transmissions deliver more power and better control than a traditional automatic transmission and
faster performance than a manual transmission.

Originally marketed by Volkswagen as the DSG and Audi as the S-Tronic, dual-clutch transmissions are now offered by several automakers, including Ford, Mitsubishi, Smart, Hyundai and Porsche.

Downshifting with Dual-clutch Transmission:
One advantage to both SMTs and dual-clutch transmissions is the ability to perform matched-rev
downshifts. When a driver selects a lower gear, both types of transmission disengage the clutch(es) and
rev the engine to the exact speed required by the selected gear.

Not only does this make for a smoother downshift, but in the case of the twin-clutch transmission, it allows plenty of time for the proper gear to be pre-selected. Most, though not all, dual-clutch transmissions can skip gears when downshifting, such as shifting from 6th gear directly down to 3rd gear.

THE MOST COMMON ISSUES WITH 7 SPEED S-TRONIC GEARBOX

Most common issue is a damaged Mechatronics. Replacement for new ranges between 1600 - 2200 GBP + VAT.

Mechatronics consists of:

S-Tronic automatic gearboxes MILTA Technology
TCU – transmissioncontrol module.

We can repair these modules under a microscope or replace for new, or re-manufactured one.

You can tell that’s a damaged TCU by flashing control lights on the dashboard. Often you will lose some gears as well. Mechatronics tends to get used around 70-120k miles.

S-Tronic automatic gearboxes MILTA Technology
VALVE BODY – pressure and
oil transmission module.

We are repairing and remanufacturing these here in our headquarters in Bristol. Valve body tends to get used/breaks around 40-80k miles.

S-Tronic automatic gearboxes MILTA Technology

WHY IT'S A SUCH A SERIOUS ISSUE?

Well, we have to start with how the gearbox is actually built.
As you know so far it’s built with two clutches. In simple words, this gearbox is built upon two small manual gearboxes. Each one of them has its own clutch. First, mini-gearbox is changing the first, third and fifth gear, the other mini-gearbox is changing second, fourth, sixth and reverse.

When we travel through motorway we tend to run in 6th gear, so 6th gear is on and the clutch is closed, therefore 5th gear is waiting ready so the clutch is open. Remember this for a moment.

Now, shifting gears and clutch from mechanical perspective is operated by the valve body, so if the valve body won’t completely drop the pressure from the ‘awaiting’ 5th gear than we are running on the partially engaged clutch! Without any idea whatsoever.

In effect, the clutch overheats and breaks and that is directly caused by malfunctioning of the mechatronic, valve body.

LESS COMMON ISSUES WITH 7 SPEED S-TRONIC

S-Tronic automatic gearboxes MILTA Technology
Mechanically damaged gearbox and usually can be identified by a lack of reverse gear.
S-Tronic automatic gearboxes MILTA Technology
Damaged and/or used bearings inside the gearbox. You can assume it’s the case by noisy work of the gearbox during accelerating, and it will go quiet when you stop accelerating.
S-Tronic automatic gearboxes MILTA Technology
Mechanically damaged gearbox and usually can be identified by a lack of reverse gear.

All of the above can be caused by:

HOW TO FIND OUT WHAT IS GOING ON WITH YOUR S-TRONIC

Mechatronic unit is responsible for selecting gears, engage clutches and monitoring overall gearbox performance. When not working properly you will experience harsh gear shifting, not engaging gears
(reverse) or knocking when downshifting.

At that stage we strongly advice to not drive the car because clutch might get damage as well. Very often car would indicate fault on the dashboard with message ‘gearbox malfunction’

Most people underestimate this issue and don’t realise it’s a serious problem.

S-Tronic automatic gearboxes MILTA Technology

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