Clutch Comeback 900 km After Overhaul
A 2018 1.5-litre diesel sedan with a six-speed manual gearbox and a dual-mass flywheel comes back 900 km after a clutch overhaul billed at 18,500 rupees. The clutch plate, cover assembly and release bearing were replaced; the flywheel was sent to a nearby lathe shop for a light reface that removed 0.6 mm, and no dial-gauge reading was taken before or after. The hydraulic release system was not pressure-bled, and the technician noticed the rear crankshaft oil seal seeping but only wiped it dry. The owner reports judder when pulling away in first and reverse, worst when the car is hot, and slip at about 2,000 rpm on a gradient with four passengers. Pedal free play measures 3 mm against a specification of 8–12 mm, and the reservoir fluid is black. The owner wants a full refund and has posted photographs of the invoice on social media. The service manager asks you to decide within a day whether this is a warranty comeback or a chargeable second repair.
1. Rank the probable causes of the judder and the slip, and give the checks that separate them before and after the gearbox comes out.
Read the worked answer
Slip at 2,000 rpm under load means clamp load is being lost or the friction face is contaminated, not that the plate is still bedding in. Judder that worsens when hot points to geometry or oil.
Ranked: first, the refaced dual-mass flywheel. Removing 0.6 mm changes the friction face height and step, so the disc is gripped unevenly and grabs as it heats. Second, oil from the seeping rear main seal reaching the disc, which is why it is worse hot. Third, air in the hydraulic release circuit combined with only 3 mm free play, so the release bearing may be riding the pressure-plate fingers and holding the clutch partly disengaged.
Before removing the gearbox: bleed the system, set free play to 8–12 mm, check for oil at the bell-housing drain plug, and road-test to see whether the slip changes once free play is correct. With the gearbox out: measure flywheel face runout and step height with a dial gauge, check the dual-mass unit for rotational play and rocking beyond specification, and inspect the disc facing for oil. Only the flywheel measurement and the seal inspection separate causes one and two conclusively.
2. Decide whether this is a warranty comeback or a chargeable repair, and state how you would justify the split to the owner.
Read the worked answer
It is a warranty comeback. The shop departed from documented practice in three ways: resurfacing a dual-mass flywheel, refitting over a leaking seal, and returning the vehicle without bleeding the hydraulic release or setting free play. The owner paid for a repair that should have restored the car, so the rework - correct flywheel or dual-mass replacement, new seal, disc if oil-soaked, bleed and adjustment - is at the shop's cost.
What is chargeable is anything the owner declined at the first visit and any unrelated fault found during the strip-down, and that must be quoted in writing before work starts.
Justify the split with the job card, photographs of the flywheel face and the seal, the measurement sheet and the free-play reading. Because the complaint is public, respond factually and privately: acknowledge the rework, give a dated completion commitment and offer a written warranty on the second repair. Do not blame the technician in front of the customer, and do not promise a refund until the strip-down confirms the cause.
3. List what should have been done differently during the first clutch job.
Read the worked answer
Check the flywheel against the maker's data before touching it. Dual-mass flywheels are generally not resurfaced; a solid flywheel may be machined only within the permitted cut, and step height and runout must be measured before and after.
Replace the rear main seal whenever the gearbox is out and there is any weep, and clean the bell housing so the new disc is not contaminated.
Bleed the hydraulic release circuit properly and set free play to 8–12 mm, checking pedal height at the same time.
Use a clutch alignment tool; support the gearbox on a jack rather than hanging it on the input shaft; check the spigot bearing and the release bearing guide tube for wear; check the flywheel bolts for stretch.
Finally, road-test before delivery. A five-minute test with four people aboard and a gradient would have found the slip, and recording flywheel runout, free play and bleed on the job card would have made this discussion unnecessary.