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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
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$1,157.55
Summit Bucks
Sonnax heavy-duty intermediate overrun clutch outer races eliminate weak points. Race failure is a chronic problem with high-torque loads causing race fractures at two stress points: the radial lube holes and the sharp inside corners at the base of the outer splines. Sonnax outer races are engineered with offset lube holes so rollers never travel directly over the holes, and they are spaced so only one roller is ever positioned near a hole, radically reducing the risk of fracture. Other design improvements to the splines, plus upgraded material and a custom manufacturing process, further improve durability, doubling the torque capacity over any OE or other aftermarket races. Sonnax heavy-duty intermediate overrun clutch outer races are direct replacements offering unrivaled reliability at any power level.
( 3 )
$101.10
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
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$770.64
Summit Bucks
Stop worrying about input shaft failure when running the GM Powerglide in the most extreme applications. Sonnax offers the only big input shaft upgrade with custom components designed to work together for reliable performance. Whether you have an existing assembly or start from scratch in the gear ratio of your choice, it's the best way to connect huge power to Sonnax Extreme planetaries for great run after run with minimum downtime. The only way to prevent twist and breakage from massive torque is to increase the input shaft diameter, and the core of the big shaft system is big input shaft kit 353532-01K. The shaft strikes the perfect balance between strength and ease of installation with a 1 1/8 in. diameter and a unique, high-strength spline that still fits through the front sun gear. It delivers 35 percent more strength than standard 1 in. shafts, a dramatic upgrade for racers that want to take full advantage of the lightweight and efficient Powerglide automatic transmission. (Note: The Sonnax big shaft system for Powerglides requires changing to a 35-spline turbine hub.) Kit contents: * Shaft * Clutch Hub Big Shaft features: * Torsional, ringless design * Heat-treated, 300M steel with advanced processing * 35 splines (AOD-style) at converter Clutch Hub features: * 1.500 in. tall hub for use with 10-clutch setups * High-strength chromoly steel * Custom fit for the big shaft
Not Yet Reviewed
$1,480.72
Summit Bucks
Sonnax adapter flange yokes are an ideal upgrade for modified performance vehicles, allowing an easy conversion from a 2-piece driveline to a one-piece, U-joint-style driveline. The yokes will dramatically increase strength and durability while reducing future maintenance costs. Benefits: * Machined 6061 T-6 aluminum construction * Eliminates the troublesome giubo and/or CV joint(s) * Great for drivetrain swaps and retrofits in custom applications, such as street rods and hot rods
Not Yet Reviewed
$287.66
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$311.37
Summit Bucks
Stop worrying about input shaft failure when running the GM Powerglide in the most extreme applications. Sonnax offers the only big input shaft upgrade with custom components designed to work together for reliable performance. Whether you have an existing assembly or start from scratch in the gear ratio of your choice, it's the best way to connect huge power to Sonnax Extreme planetaries for great run after run with minimum downtime. Additional details: * Choose from 1.69 or 1.80 ratio big shaft rear Sun Gear kits * Gear prepped to accept big input shaft's fine-tooth rear spline * Custom, PTFE-coated thrust washer replaces sun gear thrust bearing
Not Yet Reviewed
$439.47
Summit Bucks
Stop worrying about input shaft failure when running the GM Powerglide in the most extreme applications. Sonnax offers the only big input shaft upgrade with custom components designed to work together for reliable performance. Whether you have an existing assembly or start from scratch in the gear ratio of your choice, it's best way to connect huge power to Sonnax Extreme planetaries for great run after run with minimum downtime. Additional details: * Choose from 1.58 or 1.65 ratio big shaft rear Sun Gear kits * Gear prepped to accept big input shaft's fine-tooth rear spline * Custom, PTFE-coated thrust washer replaces sun gear thrust bearing
Not Yet Reviewed
$439.47
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
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$678.70
Summit Bucks
The ideal GM TH400 upgrade for any power level, Sonnax heavy-duty forward drums (34554-01) feature a unique combination of high-strength, light weight, and a cutting-edge design to optimize transmission performance. Racing applications quickly push the heavy, cast-iron OE drum over its limits, with failure most common at the weak point where the shaft and drum connect. The problem can be addressed with a larger spline and lighter-weight aftermarket aluminum drum—but durability becomes a huge issue with wear of the clutch splines, shaft spline connection, and seal ring bore. To dramatically reduce weight and deliver the ultimate in reliability, the Sonnax high-strength, chromoly steel drum is custom-engineered with several lightening features for a low rotating mass. It weighs 3 lbs. less than the OE drum and is just 3 oz. heavier than a common aluminum drum. Weight is reduced carefully, without compromising strength, by ribbing the front of the drum, adding clutch splines (28 vs. 14) and lightening holes, plus reducing the diameter inner section of the drum at the middle seal ring area. This versatile drum upgrade has an oversized 28-tooth shaft-to-drum spline and can be used with a variety of input shaft styles. This includes Sonnax 1 in. diameter, 30-spline heavy-duty input shaft 30280-02, Sonnax 1 1/8 in. diameter, 35-spline big input shaft 35280-02, and other aftermarket shafts with 28-spline connection between shaft and drum: * Ultra-modern drum delivers both high-strength and light weight for unrivaled performance at any power level * Compatible with Sonnax and other aftermarket 28-spline input shafts * Optimized for use with rubber clutch separators for applications with clean neutral setups * Clutch spline major diameter is reduced slightly, and two sets of full-length clutch splines added to back up clutch separators * Lightening holes correspond to input speed sensor locations in aftermarket cases for more accurate converter and shift data * Middle seal is eliminated—an aluminum clutch volume spacer kit 34554-11K is available separately for applications in which clutch fill/drain time may be a concern * Sonnax high-RPM checkball capsule 57510-01 is installed to eliminate pressure drop at high (5500+) RPM, a common problem with OE and other aftermarket checkballs
Not Yet Reviewed
$358.80
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