Buy Isuzu Trooper Transfer Case Input Shaft Seals

The transfer-case input shaft seal-also called an oil seal, lip seal, or front shaft seal-sits at the very front of the Isuzu Trooper's transfer gearbox. Its small rubber-and-metal ring locks transmission fluid or light gear oil inside the case while blocking water and dirt from the road. When this seal wears out, fluid drips appear at the bell-housing area, 4WD begins to chatter, and expensive gears can overheat. Knowing the Trooper's model years (1988-2002), fluid types, torque values, and proven install tricks lets owners fix leaks the first time and avoid repeat jobs. (YourMechanic, Planet Isuzoo, Wikipedia)

• Radial/lip seal design
• Isuzu workshop PDF (full drivetrain section-search "transfer case" within): Trooper manual
• Community write-up with leak photos: PlanetIsuzoo forum
• Video walk-through of seal swap (generic box-type case, steps match Trooper): YouTube tutorial

The input shaft seal presses into the transfer case front cover where the transmission's output shaft slides in. (Charm)
Inside, a garter spring hugs the shaft, keeping the sealing lip tight even as it wears. (SKF Media Hub)
Isuzu lists the most common Trooper part number as 8970467012 (superseding 8943806820 and others). (Isuzu Parts Center)
Because the Acura SLX and Holden Jackaroo share the same drivetrain, this seal fits those models, too. (eBay)

Troopers built from 1992-2002 use the Borg-Warner BW4422 or TOD (Torque-On-Demand) case; earlier models use the chain-driven standard case. (, Jeepolog)
All versions mount the seal at the 12-o'clock position on the front housing, just behind the transmission adapter plate. (Charm)
A leak here will drip onto the cross-member or starter, making it look like an engine rear-main leak at first glance. (Planet Isuzoo)

Transfer cases rely on a thin bath of Dexron III ATF or 5W-30 motor oil (1.5-2 quarts, model-dependent), so even small leaks lower the level fast. (Planet Isuzoo, Isuzu Trooper Owners Club)
Low fluid means gears run hot; heat chews up chains and synchronizers, leading to costly rebuilds. (YourMechanic, Apollo Off-Road)

• Reddish-brown spots on the driveway under the transfer case. (Planet Isuzoo)
• Burning-oil smell after highway drives. (YourMechanic)
• 4-Hi or 4-Lo popping out of gear. (Apollo Off-Road)
• Humming that rises with vehicle speed. (YourMechanic)

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• Standard case: 10W-40 engine oil, 1.5 L fill. (Isuzu Trooper Owners Club)
• TOD/BW4422 case: Dexron III ATF, 1.9 L fill. (Planet Isuzoo)
• Drain/fill plug torque: 15 ft-lb. (Merchant Automotive)
• Front flange nut (seal removal step): 145 ft-lb-stake nut after install. (Charm)

1. Support driveshaft and mark yokes before removal to keep balance. (YouTube)
2. Pop the old seal with a seal puller; avoid scratching the aluminum bore. (YourMechanic)
3. Face forward: Press the new seal so the spring side faces the fluid. (Randy's Worldwide)
4. Use a driver cup the same OD as the metal shell; tap evenly until flush. (The Timken Company)
5. Light coat of ATF on the lip before sliding the transmission yoke in to prevent a dry start. (SKF Media Hub)

Check the transfer-case level every oil change-15 minutes that can save a rebuild. (Reddit)
Inspect the breather hose; a clogged vent pressurizes the case and can blow the new seal out. (Apollo Off-Road)
If you often wade in water, switch to a double-lip seal made from nitrile or FKM rubber for extra protection. (The Timken Company)

Because the Trooper chassis underpins the Honda Passport and Opel Monterey, the same seal dimension works on those SUVs. (Honda Parts Now, PartSouq)
Manual-transmission and automatic Troopers use identical front seals; the difference lies only in rear-output seals. (Jeepolog)

The job takes about 2 hours on jack-stands with basic metric sockets and a seal driver. (YourMechanic)
If the companion flange splines are rusty or the flange nut exceeds 200 ft-lb, consider shop help and an impact gun. (Charm)

Fixing a leaking seal keeps ATF out of driveways and storm drains, protecting waterways. One quart of ATF can contaminate 250,000 gallons of water, according to environmental studies. (Apollo Off-Road)

Q: What exactly does the transfer-case input shaft seal do?
A: It locks fluid inside the 4WD transfer case where the transmission's shaft enters, and keeps dirt out so gears stay cool and lubricated. (Wikipedia)

Q: How can I tell the seal is leaking on my Trooper?
A: Look for red or dark brown drops near the transmission tunnel, a wet crossmember, or burning-oil smells after driving. (YourMechanic, Planet Isuzoo)

Q: Is it safe to drive with a minor leak?
A: Short trips may be fine, but fluid loss can empty the transfer case quickly. Running dry destroys chains and bearings, so fix the leak as soon as possible. (YourMechanic)

Q: Do I need any special tools?
A: A seal puller, 32-35 mm seal driver cup, torque wrench, and staking punch for the flange nut are the only non-basic tools required. (YouTube, Merchant Automotive)

Q: Which fluid should I refill with?
A: Standard lever-shift cases take 10W-40 engine oil; TOD/BW4422 units use Dexron III ATF. Always refill to the lower plug level. (Isuzu Trooper Owners Club, Planet Isuzoo)

Q: What torque spec does the flange nut need?
A: 145 ft-lb, then stake the nut into the shaft groove so it will not back off. (Charm)

Q: Can I upgrade to a double-lip seal?
A: Yes. Aftermarket nitrile-or-FKM double-lip seals fit the same bore and last longer in mud or water crossings. (The Timken Company)

Q: Does the seal also fit the Acura SLX?
A: Yes-the SLX is a badge-engineered Trooper, so drivetrain parts, including this seal, interchange directly. (eBay)

Q: How often should I check the seal?
A: Inspect at every oil change-about every 5,000 miles. A quick flashlight glance can catch weeping before it becomes a drip. (Reddit)

Keeping this tiny but vital seal healthy means smoother shifts, quieter 4WD, and more years on the trail for your Trooper.