PPG Gears Straight Cut Final Drive Gears for K Series

PPG K Series Final Drive Gear Set - Honda/Acura K Series FWD/AWD

Your K series transmission's got a stock final drive that's fine for a bone-stock car making 200 hp. It's not fine when you're making 500+ whp or running 10-second passes. The stock final drive gears are cast. They're designed for economy car duty. When you're launching hard or running boost, the stock gears can't handle it. They strip. They break teeth. They fail. PPG's K series final drive gear set replaces the stock cast gears with straight-cut motorsports-grade gears. These are the same gears PPG's building for their drag race gearsets. Straight-cut gears are stronger than helical gears and they reduce drivetrain power loss. You're getting more power to the wheels and you're getting gears that'll survive when you're making serious power. PPG's final drive is available in five ratios: 4.25, 4.40, 4.50, 4.61, and 4.76. Pick the ratio that matches your build. Short gears for drag racing. Taller gears for road racing. PPG's got you covered.

Here's Why the Stock Final Drive Fails

The stock K series final drive uses cast helical gears. Helical gears are quieter than straight-cut gears but they're weaker. The helical angle puts side loads on the gears that don't exist with straight-cut gears. When you're making big power and launching hard, those side loads combine with the torque loads and the gears can't handle it. The teeth strip. The gears crack. We've seen stock K series final drives fail at 400 whp just from hard launches. If you're making 600+ whp or you're drag racing, the stock final drive's living on borrowed time. PPG's final drive uses straight-cut gears. Straight-cut gears are stronger because the tooth engagement is perpendicular to the gear face. There's no side load. All the force is going into rotating the gear instead of trying to push the gears apart. The gears are also machined from billet steel instead of cast. They're way stronger than the stock gears. They'll handle 1000+ hp without blinking.

Five Ratio Options - Pick What Fits Your Build

PPG offers the K series final drive in five ratios. Each ratio changes how quickly the gears multiply engine torque. Higher numerical ratio means more mechanical advantage and quicker acceleration but lower top speed in each gear. Lower numerical ratio means less mechanical advantage and slower acceleration but higher top speed in each gear. Here's how to pick. If you're drag racing and you want the quickest ET possible, go with the 4.76 final drive. That's the shortest gear. Maximum acceleration. You'll be shifting more but you'll be accelerating harder. If you're road racing or running time attack and you need a balance between acceleration and top speed, the 4.40 or 4.50 final drives work well. They're not as short as the drag gears but they're not as tall as the stock final drive. If you're building an all-motor car and you want to stay in the powerband, the 4.61 is popular. It lets you shift through the gears and keep the engine above VTEC crossover. The 4.25 is the tallest option PPG offers. It's still shorter than some stock final drives but it gives you more top speed in each gear than the other options.

Straight-Cut Gears Reduce Power Loss

Straight-cut gears are more efficient than helical gears. Helical gears have an angled tooth face. That angle creates a side load that pushes the gears apart. The bearings have to resist that side load which creates friction and parasitic power loss. Straight-cut gears have teeth that run straight across the gear face. There's no side load. The bearings aren't fighting to keep the gears together. You're losing less power to friction. The difference isn't huge but when you're chasing every horsepower, it matters. Straight-cut gears are also louder than helical gears. There's more gear whine. That's not a defect. That's the sound of straight-cut gears engaging. If you're building a daily driver and you want it to be quiet, stick with the stock helical final drive. If you're building a race car and you care more about power delivery than noise, PPG's straight-cut final drive is what you want.

Works with Stock Gearset or PPG Drag Gears

PPG's final drive works with your stock 1st through 5th gears or with PPG's drag race gearsets. If you're just upgrading the final drive and keeping the stock transmission gears, this final drive bolts right in. You're replacing the final drive crown wheel and pinion with the PPG gears and reassembling the transmission. If you're building a full PPG drag transmission with PPG's 1st through 4th drag gears, the PPG final drive is designed to work with that gearset. Most people running PPG final drives are either building full race transmissions with PPG drag gears or they're upgrading the final drive on an otherwise stock transmission because the stock final drive failed or because they want shorter gears for drag racing. Either way works. The PPG final drive's a direct replacement for the stock final drive.

Requires OEM Honda Pinion Shaft Bearing

PPG's final drive requires an OEM Honda pinion shaft bearing. That's Honda part number 91003-PPP-004. The bearing's not included with the PPG final drive. You're sourcing it separately. Don't reuse your old bearing. The old bearing's been loaded for however many miles the transmission's got on it. Install a fresh bearing when you install the PPG final drive. Professional installation's highly recommended. You're pulling the transmission apart, removing the stock final drive, installing the PPG final drive with the new bearing, shimming everything correctly, and reassembling the transmission. If you've never built a transmission before, this isn't the time to learn. Pay someone who knows what they're doing.

What You Get

• PPG K series final drive gear set (choose ratio: 4.25, 4.40, 4.50, 4.61, or 4.76)
• Straight-cut motorsports-grade gears (not helical like stock)
• Machined from billet steel (stronger than cast stock gears)
• Direct replacement for stock K series final drive
• Works with stock transmission gears or PPG drag race gearsets
• Reduces drivetrain power loss compared to helical gears
• Designed using same profiles as PPG drag race gearsets
• Made by PPG (Pfitzner Performance Gearbox)

Final Drive Ratio Options

• 4.25 - Tallest ratio, highest top speed in each gear, slowest acceleration. Good for road racing where top speed matters.
• 4.40 - Balanced ratio for road racing and time attack. Good acceleration with reasonable top speed.
• 4.50 - Slightly shorter than 4.40. Popular for street/track builds that want more acceleration than stock.
• 4.61 - Short ratio for all-motor builds. Keeps engine above VTEC crossover through gear changes.
• 4.76 - Shortest ratio, maximum acceleration, lowest top speed. Drag racing gear.

Fits These Transmissions

• 2002-2006 Acura RSX Base/Type-S
• 2004-2008 Acura TSX
• 2003-2007 Honda Accord
• 2002-2005 Honda Civic Si
• 2006-2011 Honda Civic Si
• 2012-2015 Honda Civic Si
• 2002-2006 Honda CR-V FWD/AWD
• 2003-2011 Honda Element

Note: Straight-cut gears (louder than stock helical gears, more gear whine). Requires OEM Honda pinion shaft bearing 91003-PPP-004 (sold separately, do NOT reuse old bearing). Professional installation highly recommended (requires complete transmission disassembly, shimming, and reassembly). Works with stock transmission gears or PPG drag race gearsets. Stock cast final drive fails at 400-600 whp - PPG billet steel final drive handles 1000+ hp. Choose ratio based on application: 4.76 for drag racing (shortest, max acceleration), 4.61 for all-motor builds (keeps engine above VTEC), 4.40/4.50 for road racing/time attack (balanced), 4.25 for highest top speed. Straight-cut gears reduce drivetrain power loss compared to helical gears (more efficient, less side load on bearings). Designed using same profiles as PPG drag race gearsets. Fits all K series FWD and AWD transmissions 2002-2015.