Availability
Summit Bucks
Sonnax shift improver performance packs combine innovative heavy-duty performance calibration for firmer shifts under load without sacrificing low-speed drivability. The precision components in these kits upgrade your transmission for maximum achievement and durability by recalibrating pressures, recalibrating shift accumulation, and including improved parts for areas that commonly wear. They are suitable for any heavy-duty application and are a critical foundation for other upgrades when modifying the transmission for high performance use. Sonnax shift improver performance packs additional facts and features: * Shorter shifts, which get progressively firmer with load * Faster pressure increase and higher overall pressure for greater clutch/band holding power * Three ultra-reliable, patented, billet pinless accumulator pistons * Unique 1-2 accumulator spring combination for shifts with character * Improved high rpm pressure * Third accumulator valve gets the 2-3 right the first time, every time * Consistent results, no guessing on calibration * Prevents worn accumulators and separator plate * Optional TCC on-off conversion prevents excess TCC pressure
( 6 )
$166.99
—
$356.54
Summit Bucks
Sonnax enhanced performance accumulator springs provide firmer 1-2 shifts for enthusiasts who appreciate quick, positive shift feel in their GM units. The design of these springs provides a performance shift feel, without reducing accumulator piston travel. This allows for a firmer—but still cushioned—shift that minimizes shock to the band and shafts. These springs also may be used as a replacement for THM 350 direct accumulator piston springs. Hit the road enjoying the perfect shift feel with Sonnax enhanced performance accumulator springs.
( 2 )
$12.38
—
$25.91
Summit Bucks
Sonnax return springs are available in a variety of styles to assist in your automatic transmission rebuild. Replacement part types include high clutch return springs, pump slide springs, detent springs, reverse clutch return springs, and more. They're machined from quality materials for long-lasting performance, and can be ordered individually or in larger quantities. Select the springs required for your specific transmission application.
( 4 )
$3.38
—
$17.11
Summit Bucks
Sonnax flanged yokes will complete your driveshaft connection. These high performance 6061-T6 aluminum parts are precision-machined to be stronger than the original cast steel yokes, as well as being lighter in weight. Sonnax builds these yokes for exceptional balance and superior craftsmanship, for a show-quality driveline.
( 23 )
$45.50
—
$282.02
Summit Bucks
Vacuum testing is an efficient way to evaluate valve and valve body wear. A worn valve or valve body bore can result in incorrect pressures in the transmission, which may lead to poor performance or failure of the transmission. In order to determine if a valve/bore is worn, or to make sure a valve repair has been performed correctly, the proper vacuum testing equipment is required. Sonnax vacuum test stand kits help fill this need. Whether you're diagnosing a problem valve body or verifying your remanufacturing process, the Sonnax vacuum test stand kit will be an invaluable tool. Product details: * Quick, easy testing of valve bores * Yields repeatable numerical results for comparison and documentation * Anodized finish will stand up to years of use * Test stand features high-quality brass needle valves and a built-in test orifice for simple calibration * Clear Sonnax test plate and silicone pad ensure easy, securely-sealed testing Kit contents: * Vacuum test stand * Test plate * Vacuum plate sealing pad * Vacuum test foam pad * Push-to-connect fitting * Assorted testing tips (6) * Flexible tubing * Flared tubing with flared nut * Testing tip adapter tube
( 9 )
$274.99
Summit Bucks
Sonnax input carrier kits transform OE wide-ratio automatic transmissions into a close ratio for game-changing acceleration on the track. Manufactured and engineered for outstanding durability, these kits keep your engine in the optimal power band, while allowing a longer pull in first and second gears, improving consistency and performance. The input carrier gears are precision-ground to OE standards and feature thrust washers with a highly wear-resistant, PTFE-coated material, plus a thicker captured bearing. Lube channels direct oil to the pinion pins, and the carrier can be disassembled for inspection and service. Stay in the power band with Sonnax input carrier kits.
( 3 )
$855.99
Summit Bucks
Sonnax universal remanufactured valve bodies have been uniquely designed to fit a variety of '99-later Chrysler applications, regardless of OE checkball or solenoid configuration. The convenience of stocking one SKU number for various applications saves time, money and interchangeability confusion. The channel casting has been resurfaced to SAE recommended flatness and surface finish. The seasoned casting warpage is now eliminated, removing cross-leaks and manufacturing burrs that resulted in clutch distress and shift complaints. A new separator plate is also installed, along with gaskets, to seal the critical surfaces between the valve body and channel casting. Heavy-duty/high performance accumulator pistons with dual-guide seals are installed to prevent piston-to-bore scuffing and restore clutch pressures due to leakage. Patented Sonnax valves are installed to restore hydraulic pressures and eliminate shift complaints, trouble codes, converter concerns and overdrive clutch distress. Their patented accumulator cover plate—made from stronger, thicker material and secured with additional screws—is also installed to prevent flexing or breakage. To guarantee the highest level of operational performance, these remanufactured valve bodies are tested on state-of-the art equipment to verify that pressures match OE specification. Product notes: * One SKU fits all applications, saving time, money and confusion * Resurfaced OE channel casting eliminates warpage, burrs, and cross-leaks cost effectively * New separator plate and gaskets provide critical seal between cast surfaces * Patented Sonnax valves and pistons restore hydraulic integrity of circuits to eliminate shift complaints and clutch distress * Patented Sonnax accumulator cover plate stronger than OE to prevent flexing and breaking
( 2 )
$421.93
—
$680.85
Summit Bucks
The ideal upgrade for performance vehicles with the GM 6L80 or 6L90 transmission, Sonnax extreme-duty 4-5-6 clutch hub and intermediate shaft guarantees maximum protection against shaft breakage. The unique hub design improves oil flow and accepts Powerglide-style frictions to optimize clutch durability. In place of the 2-piece shaft/hub, Sonnax uses a much stronger, one-piece design that eliminates the OE assembly's weak, welded connection. It is custom forged from ultra-high-strength 300M billet steel, and 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.
Not Yet Reviewed
$1,015.08
—
$1,157.55
Summit Bucks
Sonnax Smart-Tech drum modules for racing GM TH400 transmissions improve on-track performance and consistency, leading to quicker ETs, more wins, and greater reliability. The TH400 is preferred for its overall durability and multitude of available ratios, but is known to be heavier and less efficient than the popular two-speed Powerglide. Part of the TH400 inefficiency results from the fact that the direct drum counter-rotates, spinning backwards in 1st gear, brakes to a complete stop on the 1-2 shift, then goes from 0 RPM to input RPM on the 2-3 shift. Significant energy is wasted through this cycle that robs power, upsets traction on the shifts, and contributes to broken internal parts. Compared to aluminum direct drums, the Smart-Tech drum module reduces the weight of the counter-rotating components by over 3.3 lbs.! And more significantly, because the weight of the Sonnax counter-rotating parts is closer to the centerline, there's a 68 percent reduction in energy required to stop and restart during the 1-2 and 2-3 shifts. The benefits are increased wheel horsepower, better acceleration, less shock on the shifts, and improved durability. * Complete kit (34555-01K) replaces both forward and direct drums and includes everything from intermediate sprag to the pump; a selection of Sonnax input shafts is available separately. * 100 percent new content, no used core pieces * Includes larger-diameter, 36-element sprag and sprag race that works with OE intermediate clutches * Includes six-friction forward clutch pack and seven-friction direct clutch pack Contents: * Forward Piston Housing * Forward Piston * Forward Piston Return Springs (16) * Forward Spring Retainer * Forward Snap Ring * O-Ring 1.674 in. * Lip Seals (2) * Direct Housing Assembly * Direct Piston * Direct Piston Return Springs (26) * Direct Spring Retainer * Direct Snap Ring * O-Ring 2.737 in. * Sprag Shaft * Front Sprag Retainer Plate * Heavy-Duty Sprag 36 Element * Outer Sprag Race * Rear Sprag Retainer Plate * Sprag Retainer Screws (4) 6-32 x 5/16 in. * Quad Ring Seals (2) * Anti-rotation Seal Rings (2) * Drum * Pressure Plate * Outer Snap Rings (4) * Bearing Small * Forward Clutch Hub * Bearing Large * Direct Clutch Hub * Steel Clutch Plates (4) .060 in. * Steel Clutch Plates (11) .077 in. * Friction Clutch Plates (13) .080 in. * Clutch Separators (60) .103 in.
Not Yet Reviewed
$3,052.40
Summit Bucks
No weak link! Sonnax heavy-duty one-piece input shafts are custom-forged from one solid piece of ultra-high-strength 300M steel. Much better than the weak OE 2-piece shaft/hub design, this single piece delivers a more robust build that will work hard longer. With durability and performance features which are second to none; your only choice should be Sonnax heavy-duty one-piece input shafts.
Not Yet Reviewed
$440.14
—
$678.70
Summit Bucks
Sonnax heavy-duty automatic transmission output shafts allow energy to be absorbed via their torsional design, reducing peak power loads to critical areas. This, in turn, prevents shaft failure common in certain GM units. These steel output shafts are precision engineered and manufactured for unbeatable performance in high-horsepower street and strip builds. They're available in various lengths, and feature many unique refinements available only from Sonnax.
( 2 )
$722.91
—
$774.01
Summit Bucks
Sonnax heavy-duty remanufactured valve bodies are built to overcome chronic shift and converter clutch apply complaints. It provides firmer shifts and a moderately increased pressure curve to improve performance, especially in truck and towing applications. Numerous Sonnax valve upgrades are included to restore hydraulic clearances that lead to shift complaints, clutch distress, converter complaints and codes, solenoid issues and pressure problems. Line pressure rise has been moderately increased to overcome shift complaints, delayed engagements, and to increase holding power to the clutches. To guarantee the highest level of operational performance, this remanufactured valve body is tested on state-of-the art equipment to verify that solenoid feed, clutch, converter, and line pressures match or exceed OE specifications. Choose your preferred kit packaged for your transmission. The valve body includes the following: * Oversized TCC regulator valve and sleeve, and limit valve spring for firmer TCC application * O-ringed bore plugs and abuse plugs * New accumulator control valve and sleeve with spring * Oversized AFL line up * New forward accumulator piston and seal * New pressure switch manifold * New EPC solenoid * New TCC PWM solenoid Kit contents: * Remanufactured valve body * Separator plate * Upper case gasket plate * Lower valve body gasket plate * 1-2, 3-4 accumulator springs * EPC solenoid harness adapter for 2003 to later units * Sonnax line pressure booster kit
( 3 )
$372.32
—
$582.46
Summit Bucks
If you're looking for an easy upgrade to your automatic transmission, Sonnax Servo piston kits may be the answer. The improvement in shift quality is an immediate and noticeable value. These direct replacement kits will help to eliminate a bit of a "sloppy" gear performance caused by faulty OEM servo units. With all necessary rings and seals to prevent leakage and handle higher pressure, Sonnax servo pistons can be your link to greater band apply force. Choose the kit that matches your vehicle specs, then expect faster and firmer shifts!
( 30 )
$15.14
—
$352.46
Summit Bucks
Failure of the intermediate stub shaft and direct drum are almost inevitable when transmissions are pushed to the limit. To maximize durability and improve clutch capacity in heavy-duty/performance vehicles, Sonnax offers Smart-Tech direct clutch drum and shaft kits, the first upgrade to eliminate every critical weakness. Most failures in these units occur where the direct drum and stub shaft connect. Even other aftermarket upgrades that rely on a heavy-duty shaft will sheer in this area under extreme conditions. Unlike two-piece assemblies, the all-in-one Smart-Tech easily handles the highest horsepower/torque levels. The unique one-piece clutch drum with integrated stub shaft is precision machined from high-strength steel to guarantee there are no splines to strip from the drum or weaken the shaft. The shaft itself is significantly thicker and 2 times stronger than the original. Due to its larger diameter, the integrated shaft must be used with the kit's custom, heavy-duty sun gear. Insufficient holding power is another area where many transmissions fall short, but installing thinner aftermarket steels and backing plates to increase clutch capacity isn't ideal. Those components increase clutch pack flex and heat build-up, making them the primary cause of repeat burn-up. To improve both performance and long-term reliability, the Smart-Tech's custom drum and piston hold an OE backing plate and seven OE frictions for 17 percent more clutch capacity than the six-friction stack-up. Sonnax Smart-Tech direct clutch drum and shaft kits feature: * One-piece design that eliminates weak point where drum splines strip and shafts break * Rugged shaft is 50 percent thicker and twice as strong as OE * Custom drum and piston deliver 17 percent more clutch capacity with optimum protection against burn-up * High-strength drum and shaft are precision-machined from hardened 8620 steel * Unique sun gear is precision-machined from 9310, heat-treated steel
( 1 )
$754.00
—
$770.64
Summit Bucks
A bad governor will result in a sudden loss of upshift. Sonnax automatic transmission governors will restore proper function on select automatic transmissions. Their governor gears are excellent replacement components and they are made of premium materials to provide a precise fit with OE quality and function for long-lasting performance.
( 20 )
$145.67
—
$170.21
Summit Bucks
Sonnax 10-clutch drum kits are optimized for Powerglide performance applications. Using the patented Sonnax 10-clutch drum system, the drum and piston accept 10 frictions and 10 Kolene steels, increasing lockup surface to allow significantly more torque than modified OE drums. The drum features a piston bore that is .060 in. deeper for greater piston travel. Kits include: * Complete 10-clutch drum kit with all related parts, including installed PTFE-coated bushing * Includes ten .060 in. frictions and ten .060 in. thick, 12-tooth Kolene steels * Excess material removed from high-strength, cast steel drum to reduce rotating mass * 6061 forged aluminum piston will not crack at high operating pressure like cast pistons * Forged chromoly steel clutch hub with lightening holes
( 1 )
$490.36
Summit Bucks
The feed limit low valve in listed GM transmissions limits line pressure feed to the default disable solenoid and control valves. Feed limit low pressure is also connected to the boost ball system for "A" and "B" clutch control. This feed limit low valve is subject to significant side-load force, resulting in severe wear and pressure loss to the default disable solenoid and connected control valves. Such pressure loss can put the vehicle into default mode at high speeds, resulting in momentary wheel lockup, sudden downshift to 2nd gear, harsh shifts or a P0747 code. The feed limit low valve can wear out in as little as 30,000 miles, with many vehicles requiring service by 35,000 miles. A national recall from GM includes installing updated software that monitors valve performance and wear, then triggers a check engine light and reduced propulsion message 10,000 miles before failure. Vehicles are then limited to 5th gear, commonly referred to as limp mode, until the valve body is serviced to address the failed valve. Sonnax patented this drop-in feed limit low valve kit to overcome bore wear, restoring proper valve function immediately without the need or expense of replacing the entire valve body. The valve reroutes the balance circuit through an internal passage, significantly reducing the side-load force, while upgraded materials prevent future wear. * The kit overcomes drivability issues related to the GM 10-speed wheel lockup recall * Patented valve and sleeve combination overcomes bore wear and significantly reduces future side loading of the valve * Hardcoat anodized aluminum valve and wear-resistant sleeve combat premature wear * Drop-in Zip Valve parts install quickly and easily * Kit contents: -- Valve -- Sleeve -- Spring -- Retainer -- Drill -- Rivet (Note: The OE feed limit low valve is susceptible to premature wear and therefore a critical failure point. Replacing the valve is recommended even if the transmission isn't exhibiting problems and the valve passes a vacuum test.)
Not Yet Reviewed
$26.86
Summit Bucks
Sonnax C ratio servo kits offer greater holding power, giving cleaner, firmer 1-2 and 2-3 shifts. They are machined from 6061 aluminum billet and feature lip seals on the piston for superior sealing over a wide range of fluid pressure. The C ratio servos are the largest in the C4 family, and will work equally well in performance C5 applications. The pins incorporate two PTFE sealing rings to insure the hydraulic integrity of the pins in worn cases. Experience firmer shifts with Sonnax C ratio servo kits. Kits include: * Piston * Cover with either purple anodized or machined finish * Servo pin with seal grooves * Gasket * Retaining ring * Spring * PTFE seals * Large and small lip seals
( 1 )
$224.07
Summit Bucks
Sonnax pressure switch rebuild kits can help salvage your transmission electro-hydraulic control module (TEHCM), restore normal switch operation, eliminate codes, and provide renewed shift performance in all ranges. Some GM transmissions send various trouble codes related to internal fluid pressure failures to your TEHCM. These codes may be accompanied by torque converter clutch (TCC) apply problems or shift irregularities such as slipping, flares, harsh application, and bind-ups. Often, the cause is laminated portions of unobtainable OE pressure switches breaching, preventing normal switch operation. Avoid multiple breakdowns that can trigger failsafe mode and TEHCM replacement by ordering the Sonnax pressure switch rebuild kit recommended for your GM transmission.
Not Yet Reviewed
$94.90
Summit Bucks
Sonnax heavy-duty automatic transmission clutch hubs eliminate hub failure. These overrun clutch hubs feature high-strength steel and thicker material for trouble-free performance when applying deceleration engine braking in D3, D2, or D1 ranges. Ready your transmission for high performance applications, such as autocross, with Sonnax heavy-duty clutch hubs. Additional info: * Two times thicker than OE clutch hubs to prevent cracking and breaking in critical areas that engage the input sprag inner race * Manufactured from high-strength 4140 chromoly steel
( 2 )
$236.88
Summit Bucks
Sonnax 10-clutch drum, hub and piston kits are optimized for Powerglide performance applications. Using the patented Sonnax 10-clutch drum system, the drum and piston accept 10 frictions and 10 Kolene steels, increasing lockup surface to allow significantly more torque than modified OE drums. The drum features a piston bore that is .060 in. deeper for greater piston travel. Sonnax 10-clutch drum, hub and piston kits include shims to make installation easy.
( 2 )
$191.36
—
$494.00
Summit Bucks
Sonnax Sure Cure automatic transmission rebuild kits are a comprehensive reconditioning package—featuring the best Sonnax products developed to help mechanics restore and enhance transmission performance. Sure Cure components are the same Sonnax parts sold individually to resolve common valve body complaints, as well as other transmission problems. The high-quality components in each Sure Cure kit will repair worn areas and protect the transmission against future damage. Plus, each kit comes with an easy-to-read, step-by-step installation guide that covers inspection and repair of the most critical areas of the valve body. Additional features and benefits: * Restore shift quality and reduce comebacks * Repairs biggest trouble areas to reduce comebacks * Includes step-by-step instructions for comprehensive valve/pump body restoration Kits Include: * Shims (2) endplay * Pump slide pivot pin * Throttle valve plunger valve kit * Shortened TV link * TV cable corrector kit * Seals D-ring servo * 1-2 or 3-4 accumulator spring * Servo release check valve kit * Reverse boost valve kit * Oversized pressure regulator valve * Pinless 1-2 or 3-4 accumulator piston kit * TV boost valve kit * Bushing pump * Bushing rear stator support * Checkballs
( 6 )
$100.75
—
$176.90
Summit Bucks
Sonnax knows you want your transmission to shift like a dream. Their automatic transmission bands are extra-wide intermediate bands suitable for heavy-duty, commercial, and 4x4 vehicles. These drop-in replacements provide 15 percent more holding capacity and feature a 60 percent thicker case anchor, decreasing the chance of band failure under severe conditions. (Note: The red-lined version of these Alto bands is designed for high-torque street racing applications. The Kevlar®-lined version is too aggressive for street use and best suited for high performance racing applications.)
( 8 )
$44.43
—
$267.47
Summit Bucks
Main shaft failure is a common problem in performance and heavy-duty GM TH400, 4L80-E and 4L85-E units. Sonnax replacement heavy-duty main shafts are manufactured from high-strength 300M with proprietary heat treatment and post heat-treat processing for exceptional performance, durability and value. These shafts are recommended for applications up to 1,000 hp. Additional details: * Advanced torsional design with spline and cross hole refinements for additional strength * Direct replacement for OE shafts
Not Yet Reviewed
$425.28
Modal Header
Truck / SUV
Jeep®
Restoration
Stock Replacement
Late Model Muscle
Tools
Gifts, Clothing, & More
Circle Track
Street Rod
Powersports
Paint & Body
Marine
Jr Dragster
