Don’t Trash Your Drill Over a Stripped Gear
Power tools take a beating on the job site. Driving 3-inch lag screws, drilling through dense concrete, or accidentally dropping the drill while the chuck is spinning can put immense stress on the internal planetary gears.
When those metal teeth finally shear off, your drill will suffer from the classic “death grind”—the motor spins flawlessly, but the chuck barely moves, or the clutch slips with zero resistance.
The DeWalt N438603 Gearbox Replacement is the complete transmission assembly designed to bring your DCD796 or DCD797 series drill back to life. Instead of spending hours trying to rebuild individual microscopic gear rings, this fully enclosed module allows you to swap the entire drivetrain in under 15 minutes.
Symptoms of a Blown DeWalt Transmission:
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The “Death Grind”: A loud, metallic clicking or grinding sound when applying pressure to a screw or drill bit.
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Loss of Torque: The drill sounds normal in the air, but the moment the bit touches wood or masonry, the chuck stops spinning.
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Speed Selector Jam: The switch on top of the drill is physically stuck, or the drill gets “caught in neutral” between speed 1 and 2.
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Hammer Function Failure: The drill rotates, but the percussive hammer action has completely failed.
Guaranteed Compatibility
This OEM-spec transmission is designed exclusively for the following DeWalt 20V MAX XR Brushless Compact Hammer Drill models:
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DCD796 (Types 1, 10, 27)
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DCD797 (Type 1)
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DCD797D2
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Note: Please check the label on the side of your drill to confirm your exact model number before ordering.
The 15-Minute Bench Fix (How to Install)
You don’t need a degree in mechanical engineering to fix your tool.
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Open the Clamshell: Remove all the T-10 Torx screws from the drill’s plastic housing and carefully separate the two halves.
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Lift the Drivetrain: Lift the motor, transmission, and chuck assembly out as one solid piece.
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Separate and Swap: Twist the old N438603 transmission slightly to detach it from the brushless motor stator. Align the gear teeth of your new transmission and lock it onto the motor.
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Align the Selector: Crucial Step: Ensure the speed selector switch (the red button on top) slots perfectly into the plastic grooves of the drill housing before closing the clamshell.
🛑 Essential Safety & Risk Management Disclaimer
Always remove the 20V lithium-ion battery before opening your power tool. The internal capacitors and battery terminals can cause severe short circuits if touched with metal tools. While this transmission comes pre-lubricated from the factory, do not introduce dirt, sawdust, or incompatible aftermarket grease into the open motor housing during installation. FixPartHub assumes no liability for tool damage caused by improper installation.
Aaron Smith –
My DCD796 was making a terrible grinding noise under heavy load. I thought the drill was completely trashed and was about to buy a new one. I ordered this DeWalt N438603 transmission assembly instead, and it dropped right in. It took me 15 minutes to swap, and the drill runs like it just came out of the box. Saved me $150 easily.
Nathan Phillips –
This transmission completely eliminated the death grind my drill was making. The internal planetary gears on this unit seem very strong. My DCD796 is back to its former glory. Highly recommend.
Benjamin Davis –
After 3 years of framing, the gearbox on my DCD797 finally gave out. It would spin in the air, but the second it touched wood, the chuck stopped. This N438603 replacement is exactly what I needed. The gears are solid and the speed selector is crisp again. Great quality aftermarket part.
Marcus Turner –
I successfully rebuilt my DeWalt drill using this N438603 gearbox. The fit was absolutely perfect. It took less than 20 minutes from start to finish. The drill performs flawlessly on the job site.
Ethan Long –
Excellent replacement part for the DCD797 hammer drill. The percussion mechanism works perfectly again. It punches through masonry without any slipping. Highly recommended for DIYers.
Dylan Powell –
This transmission saved my drill. The torque is fully restored and the grinding noise is gone. The N438603 fits the DCD796 perfectly. I will definitely buy from FixPartHub again.
Thomas Walker –
I highly recommend this gearbox if your DCD797 is slipping. The internal clutch on my old one was shot. This new assembly holds tight even on the highest drill setting. The drill feels powerful and completely refreshed.
Chase Perry –
Great gearbox! The speed selector on my DCD797 was broken, but this assembly fixed it completely. It shifts smoothly and holds the gear perfectly. I am very impressed with it.
Blake Jenkins –
The DeWalt N438603 is a very high-quality replacement part. The installation was a breeze. My DCD796 no longer makes that awful clicking noise when under load. Very satisfied.
Ashton Coleman –
This part completely restored my DCD797D2. The clutch was slipping and the gears were grinding. This new transmission assembly solved all the mechanical issues. The drill is reliable again.
Quinn Rodriguez –
My DCD797D2 was rendered useless after I dropped it off a ladder and jammed the gearbox. This replacement transmission was a lifesaver. It fit the housing perfectly and the motor attached with a simple twist. It runs strong and true.
Zane Henderson –
Perfect drop-in replacement. The internal gears of my old transmission were shattered. This new unit is smooth and quiet. My DeWalt DCD796 operates just like it did on day one.
Vincent Morris –
The DeWalt N438603 is a very high-quality replacement part. The installation was a breeze. My DCD796 no longer makes that awful clicking noise when under load. Very satisfied with this purchase.
Timothy Stewart –
Perfect drop-in replacement. The internal gears of my old transmission were shattered. This new unit is smooth and quiet. My DeWalt DCD796 operates just like it did on day one.
Umar Sanchez –
This part completely restored my DCD797D2. The clutch was slipping and the gears were grinding. This new transmission assembly solved all the mechanical issues. The drill is powerful and reliable again.
Paul Clark –
If you are a DIYer, don’t be intimidated by this repair. It’s literally just taking out screws and swapping a module. This DeWalt N438603 brought my DCD796 back from the dead. The drill sinks fasteners perfectly without any clutch slipping.
York Ross –
I highly recommend this replacement if your drill is making a grinding noise. The N438603 is a solid, well-built module. It installed easily and fixed my DCD797 instantly.
Xavier Barnes –
This gearbox is a lifesaver. The hammer function on my DCD796 had completely stopped working. This new assembly brought it back. It drills into concrete blocks effortlessly now.
Frank Anderson –
Perfect fitment for my DCD796 hammer drill. The internal planetary gears on my original unit were totally sheared off from driving long lag screws. This new transmission handles the heavy torque without any slipping or grinding noise. Feels very durable and well-machined.
Wyatt Wood –
Fast delivery and a perfect match. My drill was stuck in low gear, but this new transmission fixed the selector issue. The DCD797 shifts perfectly now. Very happy with the quality.
Lucas Roberts –
Great aftermarket part. The clutch on my DCD797 was slipping way too early. This new assembly holds the torque perfectly on the drill setting. It feels like a brand-new tool in my hand.
Colin Bailey –
This N438603 gearbox is a must-have if your drill is making a grinding noise. It completely rebuilt the drivetrain of my DCD797. The drill functions perfectly on all settings now.
Victor Bennett –
The DeWalt N438603 is the perfect fix for a drill that won’t spin under pressure. It restores the mechanical link between the motor and the chuck. My DCD796 is driving screws with ease.
Derek Green –
This transmission fixed my completely locked-up DCD797. The gears were shattered inside the old one. This replacement is smooth and quiet. It’s a very cost-effective way to save a high-end brushless tool.
Tristan Price –
Excellent part for the DCD797. The high-speed gear was completely stripped on my original transmission. This replacement gave me my speed back. It runs true and doesn’t vibrate.
Quentin Evans –
Fast delivery and a perfect match. My drill was stuck in low gear, but this new transmission fixed the selector issue. The DCD797 shifts perfectly now. Very happy with the quality of this part.
Simon Sanders –
This transmission completely eliminated the death grind my drill was making. The internal planetary gears on this unit seem very strong. My DCD796 is back to its former glory.
Riley Kelly –
I successfully rebuilt my DeWalt drill using this N438603 gearbox. The fit was absolutely perfect. It took less than 20 minutes from start to finish. The drill performs flawlessly.
Oscar Campbell –
Excellent part for the DCD797. The high-speed gear was completely stripped on my original transmission. This replacement gave me my speed back. It runs true and doesn’t vibrate under load.
Kyle Perez –
The grinding noise on my DCD796 was unbearable. This replacement transmission cured it completely. It comes pre-lubricated, which is a huge plus. The drill is incredibly smooth and quiet now.
Cody Scott –
The DeWalt N438603 is exactly what you need for a slipping clutch. My drill would just click instead of driving screws. This new transmission assembly holds strong and delivers the power effectively. Highly recommended.
Preston Brooks –
Great aftermarket part. The clutch on my DCD797 was slipping way too early. This new assembly holds the torque perfectly on the drill setting. It feels like a brand-new tool.
Bradley Murphy –
I successfully repaired my DCD796 with this transmission. It drops right in and connects to the motor easily. The drill sounds powerful and runs smoothly. Very happy with the results.
Owen Watson –
The grinding noise on my DCD796 was unbearable. This replacement transmission cured it completely. It comes pre-lubricated, which is a huge plus. The drill is smooth and quiet now.
Arthur Bell –
This gearbox is the perfect fix for a drill that’s slipping. The clutch on my DCD797 is strong again. The installation was very straightforward. Great product and fast shipping.
Nathan James –
This gearbox saved me from having to buy a new drill. The N438603 dropped right into my DCD797D2. The drill sounds powerful and doesn’t struggle under heavy loads anymore.
Brian Hill –
Great quality and a perfect fit. The terrible grinding noise is completely gone. My DCD796 sounds and feels brand new. Make sure you align the speed selector switch carefully when putting the case back together.
Julian Mitchell –
This gearbox saved me from having to buy a new $150 bare tool. The N438603 dropped right into my DCD797D2. The drill sounds powerful and doesn’t struggle under heavy loads anymore. Fantastic product.
Matthew Ramirez –
The speed selector on top of my drill was completely jammed. This transmission assembly includes the selector mechanism and fixed the issue instantly. It shifts between speeds flawlessly now.
Adam Lopez –
This gearbox completely restored the power to my DCD797D2. The old transmission was slipping under load, making it impossible to drive lag bolts. This new unit delivers full torque directly to the chuck. Awesome replacement part.
Levi Gray –
This is a highly reliable DeWalt N438603 replacement part. The gears feel very tight with no sloppy play. My DCD796 drives fasteners smoothly again. Great quality from FixPartHub.
Zachary Morgan –
The DeWalt N438603 completely eliminated the death grind on my drill. It feels incredibly sturdy and handles heavy torque well. My DCD796 is ready for another few years of hard work.
Ian Carter –
The speed selector on top of my drill was completely jammed. This transmission assembly includes the selector mechanism and fixed the issue instantly. It shifts between speed 1 and 2 flawlessly now.
Kyle Peterson –
Perfect fit for the DCD797 hammer drill. The percussive action had failed on my original unit. This new gearbox restored the hammer function perfectly. It drills into brick easily now.
Jacob Torres –
I thought my drill was trash when it started making that grinding noise. This N438603 transmission proved me wrong. It completely rebuilt the drivetrain. The drill is fully functional again.
Zane Wright –
I was skeptical about rebuilding a drill, but this made it easy. The N438603 is a fully sealed unit, so you don’t have to mess with individual tiny gears. Just swap the whole module. My DCD796 is working perfectly now.
Ethan Taylor –
I am not a professional mechanic, but replacing this gearbox was super easy. You just need a Torx screwdriver. My drill had the classic death grind, but this DeWalt N438603 completely eliminated it. It is so satisfying to fix your own tools instead of throwing them in a landfill.
York Cook –
Excellent replacement part for the DCD797 hammer drill. The percussion mechanism works perfectly again. It punches through masonry without any slipping. Highly recommended for professionals.
Hector Nelson –
This is a highly reliable DeWalt N438603 replacement part. The gears feel very tight with no sloppy play. My DCD796 drives fasteners smoothly again. I will definitely keep FixPartHub in mind for future tool repairs.
Ian Ward –
Excellent replacement gearbox. The torque is back on my DCD796. The installation was very simple and the part feels incredibly durable. It handles daily use flawlessly.
David Miller –
Excellent replacement transmission for the DCD797. The speed selector switch on my old one got permanently stuck between gears 1 and 2. This new gearbox fixed the issue instantly. It fits perfectly against the brushless motor. FixPartHub shipped it fast, which kept my downtime to a minimum.
Harrison Howard –
This transmission fixed my completely locked-up DCD797. The gears were shattered inside the old one. This replacement is smooth and quiet. It’s a very cost-effective repair.
Gavin Gonzalez –
Perfect fit for the DCD797 hammer drill. The percussive action had failed on my original unit. This new gearbox restored the hammer function perfectly. It punches through brick and mortar easily now.
Xavier Reed –
This transmission saved my drill. The torque is fully restored and the grinding noise is gone. The N438603 fits the DCD796 perfectly. I will definitely buy from FixPartHub again.
York King –
Fast shipping and the part was exactly as described. My DCD797 had a severe grinding noise in the hammer setting. This new gearbox completely fixed the percussion mechanism. It drills into concrete like a champ again.
Gregory Cox –
The DeWalt N438603 is exactly what you need for a jammed speed selector. My drill was stuck in gear 1. This new transmission assembly shifts smoothly. Highly recommended.
Charles Wilson –
This part literally saved my favorite drill. The clutch on my DCD796 was slipping constantly, even on the drill setting. I swapped the old gearbox with this DeWalt N438603 and the torque is back to 100%. The transmission came perfectly greased and ready to install. Highly recommend to any contractor.
Felix Baker –
I thought my drill was a goner when it started making that awful grinding noise. This N438603 transmission proved me wrong. It completely rebuilt the drivetrain. The drill is fully functional and ready for work again.
Xander Hernandez –
This DeWalt N438603 transmission is a beast. I use my drill for mixing thinset, which destroys gears. When mine finally blew, this replacement got me back to work. It handles the heavy, sustained torque perfectly.
Finn Richardson –
Great quality and a perfect fit. The terrible grinding noise is completely gone. My DCD796 sounds and feels brand new. The pre-greased gears make the swap very fast.
Evan Cooper –
This part completely restored the power to my DCD797D2. The old transmission was slipping under heavy load. This new unit delivers full torque directly to the chuck. Awesome replacement.
William Young –
The fitment on my DCD796 was 100% accurate. The transmission locked onto the brushless motor stator without any force. The drill sounds tight and the chuck stops instantly when you release the trigger. Very satisfied.
Damian Rivera –
Excellent aftermarket transmission. The high-speed gear was stripped on my original unit. This replacement gave me my speed back. My DeWalt DCD796 runs true and doesn’t vibrate.
Edward Adams –
Excellent replacement gearbox. The torque is back on my DCD796. The installation was very simple and the part feels incredibly durable. It’s been handling daily construction use for a month with no issues.
Victor Allen –
Excellent aftermarket gearbox. The speed selector on my DCD797 was broken, leaving me stuck in low gear. This assembly includes the whole top switch mechanism. It drops right into the plastic housing and shifts perfectly.
Ulysses Hall –
Don’t trash your DeWalt! This N438603 transmission is all you need to fix the grinding noise. It took me maybe 15 minutes to take the clamshell apart and swap it. The DCD796 runs flawlessly now. Great quality part.
Samuel Lee –
Perfect drop-in replacement. My drill was making a terrible grinding noise whenever I put pressure on the bit. This gearbox solved the issue completely. It’s great to find a reliable supplier for these specific internal components.
Wyatt Rogers –
Great gearbox! The speed selector on my DCD797 was broken, but this assembly fixed it completely. It shifts smoothly and holds the gear perfectly. I am very impressed with the build quality.
Ryan Lewis –
The gears in this N438603 transmission feel very robust. My DCD796 had completely lost its high-speed gear. Installed this part and now gear 2 screams just like it used to. It came pre-greased, which made the install even faster.
Steven Collins –
I highly recommend this replacement if your drill is making a grinding noise. The N438603 is a solid, well-built module. It installed easily and fixed my DCD797 instantly. Great value.
Oliver Robinson –
Very solid replacement part. The grinding noise on my DeWalt drill was driving me crazy. This N438603 transmission cured it instantly. The chuck doesn’t wobble and the clutch settings are accurate again. Excellent value for the price.
Noah Martinez –
The exact part I needed to fix my DCD797. The drill was stuck in speed 1 and the switch was jammed. This new transmission assembly includes the new switch mechanism, which solved the problem entirely. It shifts smoothly between high and low speed now.
Richard Edwards –
This gearbox is a lifesaver. The hammer function on my DCD796 had completely stopped working. This new assembly brought it back. It drills into concrete blocks effortlessly now.
Mason Garcia –
I run a small remodeling crew and our tools take a beating. We had two DCD796 drills go down with stripped gears in the same week. Bought two of these gearboxes and had them both back on the job site the next day. The performance is indistinguishable from OEM.
Patrick Parker –
The DeWalt N438603 is the perfect fix for a drill that won’t spin under pressure. It restores the mechanical link between the motor and the chuck. My DCD796 is driving 3-inch screws with ease again.
Liam Thompson –
This part is a massive money saver. Why buy a bare tool when you can rebuild the drivetrain in 10 minutes? The N438603 fit my DCD797 perfectly. The hammer mechanism engages perfectly when drilling into masonry. Very impressed with the build quality.
Kevin Martin –
The death grind is gone! My DCD796 sounded like a blender full of rocks. Swapped in this DeWalt N438603 gearbox and it purrs like a kitten. The torque delivery is super smooth now. Fast shipping and excellent packaging from FixPartHub.
Jack Harris –
Great quality transmission assembly. My DCD797 was totally locked up and wouldn’t spin in either direction. This replacement fixed the mechanical jam perfectly. The speed selector clicks into place firmly now. Highly recommend this for anyone doing their own tool repairs.
Isaac White –
The installation was surprisingly straightforward. I opened up my DCD796, pulled the motor and gearbox out, twisted the old one off, and snapped this one on. The drill is back to sinking 3-inch screws with zero hesitation. Best 30 bucks I’ve ever spent on tool maintenance.
Harry Jackson –
This is a highly reliable DeWalt N438603 replacement. My old transmission was leaking grease and jumping out of gear. Dropped this new one in and the drill sounds incredibly smooth. The quality of the metal gears inside feels just as heavy as the original.
George Thomas –
If your drill is making a horrific grinding noise, don’t throw it away! It’s just a blown gearbox. I bought this N438603 assembly for my DCD797D2 and it works flawlessly. The chuck spins true and the hammer function hits hard again. This is a must-have repair part.