Commander rear diff

[Vexorg]

I needed to use a super long extension to get the drill bit into the plug. I have several four letter word for the imagineer that dreamed this up. I used up the last of my 80w140 and this fall I will change again with fresh oil.
I will also order up some aftermarket (sadly from china) drain and fill plugs that have an external hex so you can use a real wrench on them.

 

[AZjeff]

That stinks. Can you get heat on the plug and some sharp raps with a metal rod?

 

[Vexorg]

That stinks. Can you get heat on the plug and some sharp raps with a metal rod?

Probably could put heat on it but the problem is the "steel" plug has an internal hex and the smallest amount of rust causes it to strip out, and the meathead who last serviced the diffs before I owned used 60 million foot pounds of torque to make sure it did not back out.

 

[QwikKota]

Where is the plug? That small item at about 4 o'clock relative to the CV boot?

 

[Vexorg]

Where is the plug? That small item at about 4 o'clock relative to the CV boot?

Ya.
The newer models have the same plug but on the bottom of the housing.

 

[QwikKota]

Ya.
The newer models have the same plug but on the bottom of the housing.

Plugs with small hex drives are terrible, regardless of location.

 

[AZjeff]

Make sure the fill plug will come out too.

 

[Vexorg]

Make sure the fill plug will come out too.

That was the first thing I did. That one was easier, but still needed an insane amount of force.

 

[Snagglefoot]

My son’s Silverado has a recessed internal hex for the fill plug in the cover of the rear diff. After spraying with liquid wrench I cleaned up the hex and plugged in my 1/4 inch Milwaukee impact wrench and gave it some Ugga Duggas. The rust was flying everywhere. It came out. If it didn’t get it out, I still had the option of buying a new cover. With the plug back in after filling, I give everything a shot of rust preventer.

 

[JohnnyG]

Plugs with small hex drives are terrible, regardless of location.

I'll second that! I still have rust embedded in the first knuckle of my right hand from trying to get one of those plugs out! And that was from 40 years ago.

 

[gasman556]

My son’s Silverado has a recessed internal hex for the fill plug in the cover of the rear diff. After spraying with liquid wrench I cleaned up the hex and plugged in my 1/4 inch Milwaukee impact wrench and gave it some Ugga Duggas. The rust was flying everywhere. It came out. If it didn’t get it out, I still had the option of buying a new cover. With the plug back in after filling, I give everything a shot of rust preventer.

would adding some anti-seize be a viable plan for these tough to access and rarely opened fill plugs?

 

[Snagglefoot]

would adding some anti-seize be a viable plan for these tough to access and rarely opened fill plugs?

Yes, I think so, but when filling or topping off the diff, I find the threads in the fill hole get some diff fluid on them and don’t think of the anti-sieze. Perhaps I’ll try it next time.

 

[QwikKota]

I'll second that! I still have rust embedded in the first knuckle of my right hand from trying to get one of those plugs out! And that was from 40 years ago.

That didn't sound fun. My second Dakota had a Mag Hytec cover on the diff and the internal hex stripped when trying to remove the large plug. I had a guy weld on a large nut and no issues after that.

 

[BrianF]

I usually use a bit of teflon tape on fill/drain plugs for auto applications as it could be years between checks or changes. Now my quads and side by side, not so much as its a yearly thing. The oil that gets on the threads is more than enough.