SRT STAGE I 6L90
• Sonnax High Capacity 4-5-6 Clutch Apply Piston Kit: features a modified OE clutch apply piston and piston dam that are used in conjunction with a specially-designed toothed apply plate closest to the piston. The Sonnax toothed apply plate increases surface area between the apply piston and first friction plate resulting in more even distribution of apply force to clutch plates and allows a friction plate to run against the apply plate. By eliminating the OE waved plate and adding one additional OE-thickness friction, 4-5-6 clutch capacity is increased by 17%, resulting in a 4-5-6 clutch pack that can handle modified engines with increased power output.
• Sonnax Heavy Duty Billet 1-2-3-4 Piston: This heavy duty 1-2-3-4 piston is made from stronger, billet aluminum and has superior design refinements that add additional strength to prevent breakage and deliver maximum performance throughout the life of the transmission. 6061 Billet aluminum with design refinements for additional strength
• Sonnax High Capacity 3-5-R Apply Ring : Sonnax high capacity 3-5-R apply ring is shorter than the OE apply ring. When the Sonnax apply ring is installed and the OE waved plate is eliminated, this allows for one additional OE thickness friction and steel plate to be installed increasing the 3-5-R clutch capacity by 25%. The extra clutch and steel also help dissipate heat resulting in a significantly more durable 3-5-R clutch pack that can handle modified engines with increased power output.
• TransGo Unbreakable High Performance Pump Ring Kit: The high-carbon steel rings in this kit have undergone a heat treatment and annealing process, making them stronger than the original equipment rings made from fragile cast iron or sintered metal. This enhanced durability eliminates the risk of breakage and associated costly pump damage. The design has been improved by reducing the inner diameter, allowing for a wider and more durable ring. This upgrade improves pump efficiency and elevates pressure at hot idle conditions, reducing the likelihood of clutch failure. The kit also includes a pressure relief spring, often overlooked despite being a common cause of low line pressure or no line pressure when it breaks.

SRT STAGE II 6L90
• Sonnax Heavy Duty 4-5-6 Clutch Hub & Intermediate Shaft:

An essential upgrade for any hard-working GM 6L80 transmission, Sonnax heavy duty 4-5-6 clutch hub and intermediate shaft 104680-36 guarantees maximum protection against shaft breakage and clutch failure in any vehicle pushing stock components to the limit. In place of the two-piece shaft/hub, Sonnax uses a much stronger, one-piece design that eliminates the OE assembly’s weak, welded connection. The one-piece design is custom forged from ultra high-strength 300M billet steel, then heat treated and shot peened for added durability. This combination of features guards against broken 4-5-6 hubs and the risk of rear splines shearing off — chronic failures in performance cars and trucks as well as heavy commercial vehicles. The 4-5-6 clutch is released in 1st, 2nd and 3rd Gears, and at high RPMs, constant oil flow is required across the spinning clutch frictions to prevent heat build-up and damaged clutches. The unique upgraded design of the Sonnax hub doubles oil flow to the clutches for significantly more protection against heat build-up and clutch failure, especially compared to other aftermarket shafts that reduce oil flow. 6L80 transmissions also have a tendency to chirp/squawk on the 3-4 shift when the 4-5-6 clutch applies. Unlike aftermarket, two-piece shafts that increase the risk of noise by eliminating the OE dampener, the heavy-duty Sonnax hub/shaft can be used with the dampener.

• 6 Pinion Heavy Duty Front Planetary: Replaces 4 Pinion Planetary Carrier

• Sonnax High Capacity 4-5-6 Clutch Apply Piston Kit: features a modified OE clutch apply piston and piston dam that are used in conjunction with a specially-designed toothed apply plate closest to the piston. The Sonnax toothed apply plate increases surface area between the apply piston and first friction plate resulting in more even distribution of apply force to clutch plates and allows a friction plate to run against the apply plate. By eliminating the OE waved plate and adding one additional OE-thickness friction, 4-5-6 clutch capacity is increased by 17%, resulting in a 4-5-6 clutch pack that can handle modified engines with increased power output.
• Sonnax Heavy Duty Billet 1-2-3-4 Piston: This heavy duty 1-2-3-4 piston is made from stronger, billet aluminum and has superior design refinements that add additional strength to prevent breakage and deliver maximum performance throughout the life of the transmission. 6061 Billet aluminum with design refinements for additional strength
• Sonnax High Capacity 3-5-R Apply Ring : Sonnax high capacity 3-5-R apply ring is shorter than the OE apply ring. When the Sonnax apply ring is installed and the OE waved plate is eliminated, this allows for one additional OE thickness friction and steel plate to be installed increasing the 3-5-R clutch capacity by 25%. The extra clutch and steel also help dissipate heat resulting in a significantly more durable 3-5-R clutch pack that can handle modified engines with increased power output.
• TransGo Unbreakable High Performance Pump Ring Kit: The high-carbon steel rings in this kit have undergone a heat treatment and annealing process, making them stronger than the original equipment rings made from fragile cast iron or sintered metal. This enhanced durability eliminates the risk of breakage and associated costly pump damage. The design has been improved by reducing the inner diameter, allowing for a wider and more durable ring. This upgrade improves pump efficiency and elevates pressure at hot idle conditions, reducing the likelihood of clutch failure. The kit also includes a pressure relief spring, often overlooked despite being a common cause of low line pressure or no line pressure when it breaks.

6L90 BUILD PARTS LIST

• MASTER KIT (BONDED PISTONS, CLUTCHES, STEELS, OVERHAUL KIT)
• Reman Pump includes Precision Machined Stator & Pump Pocket, New Pump Vanes & Rings
• TransGo Valve Body Shift Correction Kit
• TransGo Clutch Select Valve and TCC Regulator Valve Kit

Updates Details:

• Updated TransGo Valve Body Shift Correction Kit – The precision ground USA-made hardened steel PR valve provides full-time line-to-lube and restores the hydraulic integrity of the circuit. It has re-positioned longer lands at both ends of the valves which promote better support less wear. As a result, this new valve is a drop-in fix even with a pump that has substantial bore wear. A new boost valve and bushing is also provided with a built in EPC pressure relief to eliminate the possibility of damaging high line pressure spikes. In addition, to address the solenoid regulator valve bore wear, a drop in system using a precision ground USA-made hardened steel valve and a valve guide insert is used. Consequently, it no longer uses the original worn bore and easily restores the hydraulic integrity of the solenoid regulator valve circuit.
  
• TransGo Clutch Select Valve and TCC Regulator Valve Kit – The redesigned USA-made hardened steel TCC regulator valve, features longer lands which restores the hydraulic integrity of the circuit by utilizing previously unused and therefore unworn areas of their bore. In addition, the special design valve and spring calibration enables the computer to control the TCC regulation more accurately, which results in better slip control. Lastly, the drop-in USA-made hardened steel clutch select valves greatly help prevent the valves from sticking in their bores.

At Shift Rite Transmissions, we’ve got you covered with our standard 1-year 36,000-mile transmission warranty when you purchase a new torque converter, giving you peace of mind from the start. For even greater protection, we offer upgraded warranty options: a 2-year, 50,000-mile warranty and a 3-year, 100,000-mile warranty, available for an additional cost. What’s even better? You don’t have to decide right away! You can upgrade your warranty at any time during your original 1-year coverage period. Stay protected for longer, on your terms.

At Shift Rite Transmissions, we want to ensure your transmission performs at its best! Our warranty covers everything under normal use, but it won’t cover damage to cases or shafts caused by misuse, abuse, or burn down due to operator error. For the warranty to remain valid, all warranty-related work must be completed at our facility in Kankakee, IL. The vehicle owner is responsible for shipping the transmission or vehicle to us for any necessary repairs. Please note that any unauthorized repairs made to the transmission will void the warranty. Please note that our warranty is non-transferable. We’re here to support you and keep your transmission in top shape!

Buyer is required to pay the core deposit up front. Core must NOT have any internal hard part damage or case damage, otherwise there will be additional charges deducted from your core deposit for the damaged hard part(s) or case. Initial shipping cost only covers one-way shipping. Return shipping cost for the transmission core is not included. Return shipping cost is deducted from your core deposit refund, after returned core passes inspection. All Cores must be returned within 30 days from date of purchase. Please visit our Core Return Section for more details.

Majority of units are in stock, in the unlikely case we do not have one in stock, they are quickly available, in most cases, as little as one business day. There are many different variations of this transmission model available so please make sure we get a VIN number when or after you place the order.