Transfer Case

Deep Low Range Gearing Gives You Crawl Control

Stock gearing can make slow rock work jumpy. A 4.70:1 low range turns each throttle input into smooth, steady movement. You can install 4.7 gears for 21 spline cases or 4.7 gears for 23 spline cases inside your existing housing. 

For extreme gear reduction, Trail Creeper 2.28 x 4.7 Dual Transfer Cases stack two cases together. Builders creating their own doubler can begin with a 21 spline dual case adapter or a 23 spline dual case adapter.

Rebuild Parts for 1st Gen Toyota 4Runner Transfer Cases

A leaking or noisy case does not always need full replacement. Worn bearings and dried out gaskets are common trouble spots on trucks this age. These parts help you restore the case you already have:

• A major rebuild kit with bearings and gaskets for a complete overhaul
• A minor rebuild kit for lighter refresh jobs
• A gasket kit that stops stubborn gear oil leaks on 1987 and later trucks
• A heavy duty rear output seal that holds oil on steep climbs
• A magnetic drain plug that grabs metal before it reaches your gears

Finish the job with an OEM transfer case shifter boot. A cracked boot lets dirt and water fall straight into the case. This small part protects all the fresh bearings you just installed.

Shifter Upgrades and Matching Drivetrain Parts

A twin stick top shift shifter gives you separate levers for high/low and 2WD/4WD. That lets you use low range in two wheel drive for tighter turns on the trail. It is one of the most popular upgrades for owners who crawl often.

Your transfer case depends on the parts bolted around it. A worn mount lets the whole drivetrain move under load, so check your transmission parts and consider a 1984 to 1985 4Runner transmission mount. Long, sloppy throws make gear changes harder on rough ground, and a short shift kit shortens that motion. Power still has to reach the axles, so inspect your driveshaft and replace tired joints with Matsuba U joints.

Fitment Tips for Toyota 4Runner Transfer Cases

The right case depends on how your truck left the factory and how you plan to use it. Toyota made several changes across these model years. Check these details before you order:

• Count the input splines on your transmission, since cases come in 21 and 23 spline versions
• Note whether your shifter exits the top or the front of the tunnel
• Measure the offset you need when adding a second case
• Plan for armor, like a dual case crossmember for 4 cylinder trucks, when running a doubler
• Add a 27 spline triple drilled flange if a driveshaft swap is in your future

If you are unsure which setup fits your truck, call our tech support team before you order. We will help you match the right case and parts to your exact 4Runner. That way you get it right the first time.