6T75 Clutch Drum 2007-2013

If your 6T75 lost 3rd, 5th and Reverse all at once, set P0776, and the teardown turned up a shattered wave plate and chewed-up drum splines, this is the part you are looking for. This listing is a new 6T75 clutch drum for 2007-2013 units, the drum that carries the input shaft and houses two of the transmission's five clutches. It is the piece a rebuilder has to replace when a broken plate has damaged the housing too badly to reuse.

What the clutch drum does in a 6T75

GM's service information calls this part the 3-5-Reverse and 4-5-6 Clutch Housing Assembly. One housing holds both packs: the 3-5-Reverse clutch on one side and the 4-5-6 clutch on the other, each with its own piston, return spring and seals. The input shaft is part of the assembly, so engine torque coming out of the converter turns this drum first. The input speed sensor reluctor wheel also rides on it, which is why a damaged drum can upset the TCM's speed readings as well as the shifts. Apply fluid reaches the pistons through sealing rings in the case cover, so the ring lands on the drum hub have to be smooth for either clutch to hold pressure.

Symptoms of a failed 6T75 clutch drum

• No 3rd, no 5th and no Reverse together, with a check engine light (GM's wave plate bulletin describes exactly this)
• DTC P0776, pressure control solenoid 2 stuck off, which points at the 3-5-Reverse circuit
• Harsh or missing 4-5 shift, or flare on the 3-4 shift when the 4-5-6 side cannot hold
• Steel fragments and friction material in the pan and on the speed sensor magnets
• Slipping in Reverse right after a rebuild, from a worn hub or bore that leaks apply oil

How to confirm the drum is the problem

Pull every code first. P0776 with a sudden loss of 3rd, 5th and Reverse is the classic wave plate pattern, while a shudder on the 2-3 or 3-4 shift with no P0776 usually points to the valve body instead, a cheaper repair. Our 6T70 3-4 clutch failure guide separates the two. If the unit comes apart with a broken plate, inspect the drum splines where the plate teeth ride: Sonnax notes the plate usually damages those splines when it breaks. Light burrs can sometimes be dressed; notched or flattened splines mean a new housing. Also check the sealing ring lands and bushings for scoring.

Fitment

This drum is listed for the 6T75 from 2007 through 2013. The 6T75 is the heavier-torque member of the 6T70 family and shares the same basic layout, but GM revised internal parts over this span and introduced the Gen 2 update around 2013. Before you order, compare your old housing side by side with the photo: shaft length, spline count and the reluctor wheel position should all match. Check the RPO code on the Service Parts ID label, or send us your year and VIN and we will confirm. More 6T75 parts are on our 6T70 and 6T75 parts page, including the separate 6T75 input drum for 2007-13 if you are comparing listings.

Install notes

• Clean every passage before reassembly. GM's repair procedure requires flushing wave plate debris from the entire unit and replacing the pump fluid filter and the control solenoid filter plate.
• Install new piston seals, the 3-5-R and 4-5-6 sealing rings and a new wave plate; a 6T70/6T75 overhaul kit covers the soft parts.
• Air check both pistons on the bench, then set clutch clearance to spec for each pack.
• Refill with Dexron VI only and finish with the filter and pan gasket from our 6T70/6T75 filter kit.
• Clear codes and run a TCM adaptive reset and relearn with a scan tool so the new clutches are learned from scratch.

Does this 6T75 clutch drum include the input shaft?

Yes. On the 6T70 and 6T75 the input shaft is part of the 3-5-Reverse and 4-5-6 clutch housing assembly, and the listing photo shows the drum with the shaft installed.

Will a 6T70 drum fit my 6T75?

Do not assume it. The two share a design, but internal parts differ by model and revision. Match your old housing to this one, or send us the year and VIN before ordering.

Do I have to replace the drum if the wave plate broke?

Only if the splines or bores are damaged. Inspect where the plate teeth ride. Burred, notched or flattened splines mean the new plate will not seat correctly and the housing should be replaced.

What should I replace along with the drum?

A new 3-5-R wave plate, piston seals and sealing rings, clutch plates for both packs, the pump fluid filter, and the control solenoid filter plate GM calls for after a wave plate failure.

Is my 6T75 still covered by GM's wave plate special coverage?

Special Coverage 14404B ran 10 years or 120,000 miles from the original in-service date on 2007-2009 vehicles, so that window has closed for the covered vehicles.

What fluid and relearn does it need?

Dexron VI ATF. After the rebuild, clear codes and perform the transmission adaptive reset and relearn with a capable scan tool.

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