Rear Differential Drain And Fill Plugs Removal

[westslope]

Finally getting around to draining and the refilling the rear differential fluid. How do I remove the plugs?

The closet thing I have to fill the square hole is a 3/8 inch socket adapter (from 1/2 inch). I tried using with the brushless impact wrench, a mistake, as it did not loosen the fill plug and seems to have worn the plug. Going forward I will use a breaker bar.

Is there a better bit to use than a socket adapter? I have looked with no success so far.



Note that the stain around the fill plug is PB Blaster!



Suggestions? Wondering if I should buy replacement plugs before I proceed. Thoughts?

 

[Muadeeb]

Looks like a naked 1/2 will do it. Might need to use the box wrench cheater method.

 

[maillet282]

the last time I changed the diff oil all I used as a 1/2 ratchet and was able to successfully remove the fill plug as well as the drain plug. I always try the fill plug first just in case I can't remove it. no point removing the drain plug

 

[westslope]

the last time I changed the diff oil all I used as a 1/2 ratchet and was able to successfully remove the fill plug as well as the drain plug. I always try the fill plug first just in case I can't remove it. no point removing the drain plug

You have a different differential cover - Shrock, correct?

My diff cover is stock. I tried a 1/2 inch ratchet and it did not fit. Maybe I should clean out the plug hole with a wire brush and scrape it with a knife and a flat blade screw driver?

 

[jsexton]

Use a 1/2” extension.

 

[westslope]

Use a 1/2” extension.

Easy peezy. So, in my case why does it not fit?

 

[westslope]

FWIW, I actually tried hammering a 1/2 inch extension into the fill plug with a rubber mallet. Not even close.

Here are some more pictures that may help. The fill plug hole is a little ratty (after I used an impact wrench) but the drain plug hole is rather clean and will not accept a 1/2 inch extension.

Drain plug first with 3/8 inch adapter inserted:






Again the filler plug immediately below with the 3/8 inch adapter:




Below, an attempt to insert the 1/2 inch extension:




The 1/2 inch extension does not fit the drain plug hole which appears to be relatively corrosion free. See below:




No happiness trying to jam the 1/2 inch extension in:




The 3/8 inch adapter easily fits:




Is it possible that the corrosion has been so bad that the fill and plug holes shrunk in size? If so, how do I remedy that?

I can try a breaker bar again with the 3/8 inch adapter but would prefer to use the 1/2 inch extension if possible, given the force that will be required.

 

[outback97]

Those plugs are supposed to be 3/8" square drive. I'm confused by the recommendations for the OP to try 1/2".

On my '06 OR with stock differential cover, I have just used a 3/8" breaker bar with a short extension. You could try a different 3/8" drive and hand tools only... maybe the 1/2 to 3/8 adapter you have has just a little more slop in it?

There's also these:

If the plug is too buggered up to take out with a 3/8" drive, what about a pipe nipple extractor set to get the plug out? Then replace with a new plug? I have had good luck with them on pipes but never used them for this purpose.

https://www.homedepot.com/p/Husky-Pipe-Nipple-Extractor-Set-6-Piece-410-391-0111/309997715

 

[jsexton]

Bad memory. Must be 3/8”. Either way it’s designed for an extension.

 

[westslope]

outback97: Thanks for the suggestions.

I have a 1/2 inch flexible extension of impact wrench quality that could work:



Otherwise, I will order replacement plugs (to be safe). Home Depot Canada does not carry pipe nipple extractors but Amazon.ca does. I see that bolt screw extractors might work but the pipe nipple extractors look the most suited to the plugs.

jsexton and others: Yup. Extensions and hand tools.

The factory service manual (FSM) calls for 35 lb. torque for the fill plug and 27 lb. torque for the drain plug. I thought the impact wrench would easily dislodge the fill plug. I thought wrong.

 

[westslope]

Follow up.

Bought a 1/2 inch to 3/8 inch adapter impact socket. That did the trick with a breaker bar. Managed to remove the filler and drain plugs with relative ease.





Replaced the old filler plugs with new ones. Both new ones came with magnetic bottoms.





New drain and filler plugs installed.