Clutch Wear

User manual

Reading the values

Updated 27 August 2026 · this is the same reference that ships inside the app

How to take a clutch wear measurement and turn it into a report the customer understands. Channel numbers and limits come from the factory documents and the workshop spreadsheet the app replaces. The exact menu path differs between diagnostic testers, so each model in the app has a note you fill in with the route on your own equipment.

How a job runs

  1. Read the tester. Put the car on the diagnostic tester and open the clutch measurement values for that model.
  2. Type them in. Pick the model and enter the readings. The dial updates as you type, so a typo shows up immediately as a nonsense result.
  3. Add plate and technician. Scan or type the VIN if you want the car findable later.
  4. Print. One page for the customer and the service advisor, saved to history at the same time.

Lamborghini Gallardo

e-gear · LP560-4 / 09–13MY

Control unitE-GEAR control unit
WhereMeasurement values → channel 10. The two clutch positions are on lines 3 and 4 of that channel.
Limit in use5.2 mm maximum wear

What each value is

  • Line 3 — closed position — the position recorded when the clutch was new
  • Line 4 — closed position (learned) — the position the gearbox has learned now

How wear is worked out

Wear = line 4 − line 3. The clutch closes further as the friction material thins, so this number grows over the clutch's life.

Units

Values may appear in bits. 60 bits = 1 mm — tick the bits box and the app converts.

Also worth reading

Channel 10 also carries two health values worth entering: 10.1 clutch wear index (factory default 4000, deteriorated above 15000) and 10.2 kiss point (default 480, deteriorated above 800). Both are independent of thickness — a clutch can be within its wear limit and still be failing on these.

Watch out. The factory training document quotes 5.6 mm for this measurement while the workshop spreadsheet uses 5.2 mm. The app defaults to 5.2 mm, which reports slightly more wear. Change it on the limit chip if your documentation says otherwise.

Lamborghini Murciélago

e-gear

Control unite-gear control unit
WhereMeasurement values. The two positions are on separate channels, 19 and 27 — not two lines of one channel.
Limit in use7.6 mm maximum wear

What each value is

  • Ch 19 — closed position (learned) — the new-clutch reference
  • Ch 27 — closed position (current) — the value now

How wear is worked out

Wear = Ch 19 − Ch 27. Note this is the opposite subtraction to the Gallardo: on this platform the position falls as the clutch wears.

Units

Enter the values in millimetres as the tester shows them.

Also worth reading

The PIS biting-point table is on the measurement screen in the app — default D7 = 215 bit, adjust in steps of no more than 3 bit between tests. It changes how the car pulls away; it is not a wear figure and never appears on the report.

Watch out. Because the subtraction runs the other way here, swapped values give a negative result. The app warns you rather than printing nonsense — if you see that warning, check which channel went in which field.

Lamborghini Aventador

ISR

Control unitISR gearbox control unit
WhereMeasured value block MVB 18, line 2 — “present clutch wear”.
Limit in use7 mm maximum wear

What each value is

  • MVB 18.2 — present clutch wear — wear in millimetres, already calculated by the control unit

How wear is worked out

No arithmetic. The control unit reports wear directly, so the figure goes straight into the app.

Units

Millimetres as displayed.

Watch out. Because this value comes pre-calculated, there is no new-clutch reference to check against. If a clutch was replaced without the adaptation being reset, this figure keeps counting from the old clutch.

Audi R8

R tronic · single clutch

Control unitR tronic gearbox control unit
WhereMeasurement 10.3 and 10.4, the same channel layout as the Gallardo — the two cars are close relatives.
Limit in use5.5 mm maximum wear

What each value is

  • 10.3 — position clutch closed (learned) — the new-clutch reference, in bits
  • 10.4 — closed, current driving cycle — the value now, in bits

How wear is worked out

Wear = (10.4 − 10.3) ÷ 60. The app does the division — enter the raw bit values as the tester shows them.

Units

Bits throughout. 60 bits = 1 mm. There is no bits toggle here because the conversion is always applied.

Watch out. Enter bits, not millimetres. Typing a converted millimetre value gives a wear figure sixty times too small and a clutch that looks brand new.

Aston Martin

AMT / Sportshift

Control unitAMT / Sportshift gearbox control unit
WhereClutch wear index in the gearbox measurement values.
Limit in useindex 1200 (new) to 1800 (worn out)

What each value is

  • Clutch wear index — a single counter that rises as the clutch wears

How wear is worked out

Wear is interpolated on the index scale: 1200 = new, 1800 = worn out. The app converts that to a percentage.

Units

A plain counter — no unit, no conversion.

Watch out. Aston Martin's own bulletins define the index but publish no numeric new/worn thresholds; 1200 and 1800 come from the workshop spreadsheet. Treat them as a working scale. If you have a reading from a known-fresh clutch, set that as the new value on the limit chip — a baseline from a car you have seen beats a number from a forum.

Reading the result

ShowsMeans
Green, over 35%Plenty of friction material left. Nothing to do at this service.
Amber, 15–35%Wearing out. Tell the customer now so replacement is planned, not an emergency. With mileage entered, the report adds an indicative remaining distance.
Red, under 15%Replacement recommended. At zero the clutch has reached its wear limit.

The percentage is material remaining, not a health score. It is the measured wear against the maximum wear allowed for that model — nothing else is folded in.

If something looks wrong

SymptomUsually means
Negative wearThe two values are the wrong way round, or the clutch and its adaptation were renewed and the reference has been reset.
Wear far too highThe tester is showing bits, not millimetres. 60 bits = 1 mm.
Almost no wear on a tired clutchThe new-clutch reference was re-learned at some point, so wear is counted from that moment rather than from new.
Result disagrees with the feel of the carWear is one measurement. Glazing, contamination, a bad kiss point or hydraulic problems all cause slip at healthy thickness.

Changing a wear limit

Every limit is editable — tap the limit chip beside Tester values in the app. A changed limit is marked on the printed report, so the customer's copy always says which figure was used.

The wear limits shipped in the app come from a workshop spreadsheet and the factory documents behind it. Where a factory document and the spreadsheet disagree, the app says so in the guide and lets you decide. Always check against the manufacturer's current service documentation before advising a customer.

What the app stores

Everything stays on the device: the jobs you print, the workshop name, the technician name and the wear limits you have changed. Nothing is uploaded. Back the jobs up to a file from the Guide screen before changing phone — see the privacy policy for the detail.