laying under the vehicle ,on the side of the rear housing pointing towards the passengerside of vehicle you should see a plug ,a 3/8 extension should fit that plug, unscrew it, if it is full it should seep out after plug is removed or should just be inside hole when touched by finger. if more needs to be added ,add only til it spills out and replace plug
I had a 5400 and on the back of the rear differential there will be a fill cap and a fluid level glass window set into the back of the diff, the fluid level should be across the middle of the glass
Different vehicles have different rear hub fluid checking/filling system. Normally you have a bolt, you undo the bolt for checking the fluid level, if necessary replenish the level. Newaz.
on level ground remove the center plug on the 3rd member rear side. if fluid is level with bottom edge, then is it full if fluld is not amber and clear, but cloudy , then it is water logged.
On the differential there should be a plug with a 3/8 or 1/2 inch square on it that you can use a socket wrench to remove, just stick your finger in and feel if there is fluid. If there is no fluid, fill to that level.
I you have the All Wheel Drive (AWD) version - you should check the level of the fluid in your rear differential case. If the level of fluid is okay, you may have a rear wheel bearing that is going bad.
Take out the fill plug and stick your pinky finger in. The fluid should be to the edge of the fill. If you are experiencing mild rear problems (clicking etc), change the fluid before you get permanent damage. Use GM gear fluid and additive from dealer.
The transmission fluid dipstick is located on the passenger side near the top rear of the engine. With the engine running, remove the dipstick and check the level on the stick.
You fill it up with 90 weight (WT) gear oil unless you have positrac rear end, then it's a gear oil / transmission mix (check with GM). It should take around 1.5 quarts. It's not a specific amount, it is fill thru the check hole/plug until it start coming back out when the truck is parked on level ground. This means you fill it until the oil is the same level as the bottom of the hole where you are checking the level. This answer applies the 90% of rear wheel drive automobiles and trucks.
The level check for the hydraulics/transmission/rear axle is pipe plug on the left side of the tractor just in front of the rear axle housing. Oil is supposed to be at that level with all hydraulics extended.
Automatic--use the available Dip Stick which should be labeled for Transmission.Manual--underneath car at Transmission there should be a Fluid Check Plug/Bolt. Remove Plug/Bolt and if no Fluid appears, insert small finger to hopefully remove with Fluid upon. If no Fluid is detected, ADD FLUID at Add point, or DRAIN and REFILL.If Rear Gear (Is it Rear Drive??), there may or not be a Fluid Check Bolt.See Below!!Acquiring a Repair Manual specific to the Vehicle Year/Model will most assuredly help with ALL diagnostic problems.
to check fluid level raise the top and remove rear seat cushion put some rags below the filler plug remove plug fluid level should be level with bottom edge of hole do not operate top with plug removed if fluid is low check system for leaks and add fluid REPLACE plug
on the rear of the case there is a fluid fill line next to the fill bolt. Remove fill bolt and stick your finger in.