Rear diff fluid level

[ramblinboy]

Hi all looking for an answer on my rear diff fluid level. 2008 Workhorse 8.1L.
I opened the top screw and held in a popsicle stick to check levels. It came up dry. Anyone? Thx

[Old Scout]

Generally--the top plug on a diff is the "full" level but with in an inch or so is probably good....

[Skip426]

Some manufacturers, say even with the threads, on the bottom of the plug; others , within 1/2" is OK.
If the coach is on level ground, try using a piece of wire coat hanger, with about the last inch, bent at right angle. If you don't reach the fluid , time to add , and look for leaks.
Were you the last person to check the fluid ?
Or is the coach new to you and your doing this for the first time ?

[Argosy]

Stick your little finger in the hole to the knuckle closest to your hand. Bend it down, if it touches oil you're good. If it's low fill it until it begins to run out.

[ramblinboy]

theres no check on the back like the usual diff - its a smooth ball with a check hole on top. too small for finger so used popsicle to check. I should have struck some fluid on a 4" stick ud think - scratching head symbol. First time Ive checked on my used rig.
Ill try a longer dip - thanks for the advice!

[Skip426]

Should be a check/ fill plug somewhere. Up the side of the pinion housing, possible hidden above a reinforcement casting . Sounds like you've got the vent out , if the hole is that small.

[ramblinboy]

Ya sounds more like a vent given the size. Theres is a big Allan type plug on the lower housing with the usual seepage around it. Ill try that - what tool is that? Its a Dana S130

Originally Posted by Skip426

Should be a check/ fill plug somewhere. Up the side of the pinion housing, possible hidden above a reinforcement casting . Sounds like you've got the vent out , if the hole is that small.

[Skip426]

Can't say for sure, and can't check , B-in-Law sold his 05 for health reasons , so I can't even go and look.
The fluid level in the housing should be just below the center line of the pinion; if the plug is lower than the pinion don't pull it.

Have a catch bucket handy and be ready to jam it back in.

BTW. I was told 16 pints capacity on my diff, when doing a change, turned out to be 16Quarts, and there was me with a 12 quart drain pan.

[ramblinboy]

In this top view there are 2 plugs

[Argosy]

The bottom one is to check the level and fill.

[ramblinboy]

Thanks all. Things look different under there with no headroom lying on your back. Im guessing the plug comes out using a bare tip socket wrench?

[RetiredBob]

Originally Posted by ramblinboy

Thanks all. Things look different under there with no headroom lying on your back. Im guessing the plug comes out using a bare tip socket wrench?

Yep, a 1/2" socket wrench.