4L80E, 4L85E

GM '99-later 4L80-E and 4L85-E transmissions can suffer intermediate backing plate breakage, clutch failure and case lug blow out when pressures are increased for more clutch holding capacity. This Sonnax .275" thick, heavy duty intermediate clutch backing plate is made of billet steel to withstand higher pressures and features lugs around the entire perimeter to improve durability.

• Stronger material and full set of case lugs prevent failure at higher pressures
• Compatible with OE and aftermarket cases
• Use with Sonnax case saver retainer # 38976S to eliminate OE case lug blow out, no plate modifications required