6T45 Sprag Clutch 2008-2013

The 6T45 is the heavier-duty member of GM's six-speed front-drive family, found behind engines such as the 2.4L in the Equinox and Terrain. When an early one loses first gear in Drive, slips in reverse, or a teardown turns up a cracked piston, the fix is often in one assembly. This remanufactured GM part is the first-generation low/reverse and 1-2-3-4 clutch housing, pictured with the low one-way clutch installed, listed for 2008-2013 6T45 transmissions. GM reference 24252792.

What the housing and low sprag do in a 6T45

Inside the 6T45 this aluminum assembly stays still and acts as a brake. It holds two bonded pistons, one for the 1-2-3-4 clutch and one for the low/reverse clutch, and it carries the low one-way clutch, a mechanical diode rather than a roller sprag. First gear in Drive is the 1-2-3-4 clutch plus the diode holding. Second through sixth let the diode overrun. Reverse and manual first use the low/reverse clutch. On a 6T45, which sees more torque and often more towing than a 6T40 in a compact car, a tired diode or leaking piston shows up first on loaded launches.

Symptoms that point to this assembly

• Revs and creeps in Drive from a stop, yet moves normally in manual first
• Slip in first through fourth, often with P2723, from a cracked 1-2-3-4 piston
• Delayed or soft reverse, or slip in manual first, from the low/reverse piston
• Clunk or ratchet noise coasting down, and diode or piston debris in the pan

Rule out the other 6T45 problems first

Not every early 6T45 complaint is mechanical. GM issued a TCM calibration for a harsh 2-3 shift on 2011 Equinox, Terrain and Captiva 2.4L models, and Gen 1 internal pressure switches and solenoids can drop gears with codes such as P0878. Check those with the shift solenoid guide, which applies to the 6T45 as well. A soft or late engagement into Drive or reverse is covered in our delayed engagement guide. If the unit is coming apart, inspect the 3-5-R wave plate too; cracking at its tooth corners is a known failure across these units and is covered in the 6T40/6T45 common problems guide.

Fitment

Listed for 2008-2013 first-generation 6T45 units, and shared with the Gen 1 6T40, where it is also listed as the 6T40 sprag clutch 2008-2013. GM phased in the Gen 2 design starting in 2012, and later 6T45 units use different internal parts, so a 2012 or 2013 vehicle needs checking. Compare your housing, piston layout and diode with the photo, or send us the year and VIN. If you want only the one-way clutch for a 2008 unit, see the 2008 6T45 sprag. For a full overhaul, the 6T40E/6T45 master rebuild kit supplies the soft parts.

Install notes

• Replace both bonded pistons any time this assembly is serviced; the 6T40/6T45 bonded piston set fits.
• Verify diode direction by hand before assembly; installed backward it gives no first in Drive.
• On Gen 1 controls, a TransGo Gen 1 valve body repair kit addresses known valve wear while the pan is off.
• Refill with Dexron VI, set the level at the check plug with the fluid hot, then clear adapts and relearn.

Is this the same part as the 6T40 2008-2013 listing?

Yes. The first-generation low/reverse and 1-2-3-4 housing is shared by the 6T40 and 6T45, so it is listed under both.

Does it fit a 2013 Equinox or Terrain?

Only if the transmission is still Gen 1. GM began the Gen 2 change in 2012, so send us your VIN or compare your old housing with the photo.

Does it come with the sprag installed?

The photo shows the low one-way clutch seated in the housing. Contact us before ordering if you need to confirm the exact contents.

My 2011 Equinox 2.4L shifts hard 2-3. Is this the fix?

Probably not. GM corrected that complaint with a TCM calibration. This housing addresses first gear, reverse and 1-2-3-4 clutch failures.

What fluid does the 6T45 take?

Dexron VI. Set the level hot at the check plug after the repair.

• 6T40 Common Problems and Fixes
• 6T40 Shift Solenoid Symptoms and Replacement
• 6T40 Delayed Engagement: Causes and Fix
• 6T40 Fluid Change Cost