1A Auto Video Library
Our how-to videos have helped repair over 100 million vehicles

How Change Transfer Case Fluid 99-06 GMC Sierra 2500 HD

Share on:
  1. step : Draining the Transfer Case Fluid (0:57)
    • Using an 18mm socket, remove the drain plug.
    • Drain the fluid into a catch pan.
    • Reinsert the drain plug.
  2. step : Filling the Transfer Case (1:45)
    • Using an 18mm socket, remove the fill cap.
    • Place a funnel with a tube into the fill hole.
    • Fill with 5 pints/ 2 Â1/4 quarts of transmission fluid.
    • When the fluid stops coming out the fill hole replace the cap.
    • Wipe it down and check for leaks.

Brought to you by, your source for quality replacements parts and the best service on the internet.

Hi, I'm Mike from 1A Auto. I hope this how-to video helps you out and next time you need parts for your vehicle, think of Thanks.

In this video I'm going to change the transfer case, the four wheel drive transfer case fluid on this 2002 GMC Sierra. Pretty easy. All you need is an 18mm wrench a catch pan, a funnel with a tube on it and then the appropriate fluid.
These 2002s, this has the push button four wheel drive. It actually uses a type of automatic transmission fluid.
In the video I do have the truck on a lift but these trucks are high enough off the ground that you can actually do this just by going right underneath the truck. You don't need a jack or jack stands but you do want to make sure it's in parked, emergency brake is set and the wheel is blocked.

Start with an 18mm socket ratchet or wrench and remove the drain plug on the back of the transfer case. Make sure you have a catch pan underneath. Now up a little higher. There you can the fill plug. Now you want to refill it. We use a funnel. You basically just want to fill it until fluid starts coming out of the fill hole and that's usually, well this take up to just a little over five pints which is two and a half quartz. I usually put in couple quartz and then see where it goes from there.

This truck is 2002 so it actually uses the Dex/Merc automatic transmission fluid. I just put the funnel right up there. Two quartz or four pints. When I pulled the funnel out, fluid came out so I'm letting fluid drain down into my catch pan still. Once it slows down to a trickle, I put the plug back in. Tighten up the fill plug. I just make sure that I wipe it down really well that way I can inspect it after a while and just make sure there's nothing leaking out.

We hope this helps you out. Brought to you by, your source for quality replacement parts and the best service on the internet. Please feel free to call us toll free 888-844-3393. We're the company that's here for you on the internet and in person.

Tools needed for replacement:

    General Tools

  • Funnel
  • Drain Pan

  • Ratchets & Related

  • Ratchet

  • Sockets - Metric

  • 18mm Socket

Search Videos
Go To Top

Same Day Shipping

Orders ship same day when ordered by 2pm ET. Need your part faster? Choose expedited shipping at checkout.

Guaranteed To Fit

Providing you the highest quality, direct fit replacement auto parts enforced to the strictest product standards.

USA Customer Support

Exceeding customers' expectations every day, our team of passionate auto enthusiasts are here to help.

Instructional Video Library

Thousands of how-to auto repair videos specific to year, make and model guide you step-by-step through your repair.