6T75 Banner Rebuild Kit

If your GM crossover or sedan with the 6T75 six-speed has started slipping, flaring between gears, engaging late into Drive, or has dropped reverse along with 3rd and 5th, the transaxle is past the point where a fluid change helps. This new 6T75 banner rebuild kit is built for that teardown. It gives you the soft parts a standard overhaul calls for in one order, so the unit goes back together with fresh sealing instead of a mix of new and reused pieces. The main photo shows the gasket and seal side of the kit: valve body spacer plate gaskets, metal-clad lip seals, sealing rings and O-rings.

What a banner kit does in a 6T75

The 6T75 is the heavier-duty member of GM's 6T70/6T75 front-wheel-drive family. It makes six forward speeds with five clutch packs: 1-2-3-4, 2-6, 3-5-Reverse, 4-5-6 and Low/Reverse. Each pack is applied by a hydraulic piston, and that pressure is fed through sealing rings on rotating hubs and through gaskets between the case, the channel plate and the valve body. When those seals harden or the frictions glaze, apply pressure bleeds off and the clutch slips. A banner kit pairs a complete overhaul gasket and seal set with new friction plates, which covers the wear items of a normal rebuild for less money than a full master kit.

Symptoms that point to a rebuild

• Slipping or a rising RPM flare on upshifts, worst when the fluid is hot.
• Delayed or soft engagement into Drive or Reverse from leaking piston seals.
• Burnt, dark fluid with friction material on the pan magnet.
• No reverse, no 3rd and no 5th with DTC P0776. ATRA ties this to a broken 3-5-Reverse wave plate letting the piston over-stroke and leak; P0777, P2723, P2715 and P0717 can set from the same failure.
• A bind on the 3-4 or 4-3 shift, sometimes with P0797, caused by a worn ring groove on the case cover hub sleeve leaking between the 3-5-Reverse and 4-5-6 circuits.

How to confirm it before you buy

Check the fluid level and smell it, then scan for stored codes. A quick check ATRA recommends for the no-reverse complaint: unplug the transmission connector. If reverse engages unplugged, the problem is not mechanical in the shell. If the pan holds clutch debris or metal, plan on a teardown. Our 6T70 and 6T75 common problems guide walks through which failures need a kit and which are controls faults, and the rebuild cost guide lays out where the money goes.

Fitment

This listing is for the 6T75 without a specific year range, so match it to your unit before ordering. GM made a major controls update for 2013 (the Gen 2 units), and parts changed along the way, including updated wave plates for every clutch and a revised 2-6 clutch snap ring and case groove. Read the RPO code from the Service Parts Identification label or send us your year and VIN and we will confirm the kit is correct. If you have a 2013 unit, compare this kit with our 2013 6T75 banner kit. All parts for this family are on the 6T70/6T75 collection page.

Install notes

• Raise the torque converter straight up. There is no seal on the turbine shaft; the lip seal sits inside the converter and is damaged by pulling it out at an angle.
• Install updated wave plates in all clutches, not only the 3-5-Reverse. ATRA warns that debris from a broken plate destroys the planetary.
• Pull the hub from the rear case cover and check ring-to-groove clearance with a feeler gauge. ATRA lists 0.007 in. as the maximum; replace the case cover if it is worn past that.
• Use a sizing tool for the hub sealing rings, such as our sealing ring installer kit.
• Inspect drum splines. Sonnax notes a damaged 3-5-Reverse drum means a new housing, like this 6T75 clutch drum.
• Replace the internal filter now; it is only serviced after internal repair. Refill with DEXRON-VI and run the clutch learn procedure.

Does this kit fit every 6T75?

It is listed for the 6T75 without a year range. Parts changed with the 2013 controls update, so send us your year and VIN or the RPO code from the Service Parts Identification label and we will confirm the match.

What is in a banner kit compared with a master kit?

A banner kit combines the overhaul gaskets and seals with new friction plates. A master kit usually adds steel plates and sometimes pistons. If your steels are heat-blued or warped, buy steels too.

Will a rebuild with this kit fix P0776 and no reverse?

Usually the cause is a broken 3-5-Reverse wave plate. Rebuild with updated wave plates in all clutches and check the drum splines and planetary for debris damage, since those are not in a soft-parts kit.

What fluid does the 6T75 take?

DEXRON-VI. Check the level with the transmission at operating temperature after the rebuild.

Do I need to do anything with the computer after installing it?

Yes. The TCM learns clutch fill volumes, so run the service fast learn or drive learn after the rebuild. Without it, early shifts can feel harsh.

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