Differential fill plug

[rocketman]

Any suggestions on how to remove or even loosen a rear differential fill plug that WILL NOT budge? I changed the fluid a couple of years ago, been trying for a while to check on it during my reg. maintenance checks - 1999 Silverado, 191,00 km.

 

[1 FMF]

3/8" ratchet with a 3" long extension,
the square head of the extension should fit tight into the plug, use a decent length of pipe slid over the handle of your ratchet to give you leverage. black pipe works real nice, you can get it at any hardware store- lowes or depot.

 

[Eddie]

In addition; I would tap the 3/8 drive into the plug to make sure you get all the area of the plug involved.

 

[Matt_S]

A torch to heat the area around the plug will expand the threads in the housing and should help break the plug loose more easily.

 

[Kestas]

I had the same trouble with my neighbor's Silverado. I used a 3/8-inch breaker bar and a hydraulic jack to move the breaker bar. The weight of the vehicle loosened the plug. Ditto to Eddie's advice to maximize the purchase at the plug.

Make sure to reinstall the plug with teflon tape on the threads to make the next service easier.

 

[alreadygone]

At my shop we often find plugs that have been rounded off untill 3/8 square will no longer hold. To remove I grind 4 flats onto the end of a 1/2 inch bolt untill it can be driven into the plug. Then weld in place. While bolt and plug (now 1 piece) are still hot I remove with 3/4" box end wrench. Now you have a plug that extends outward from differential and can be turned with any 3/4" wrench or socket.

 

[Lonnie]

Don't put a cheater on a ratchet, use a breaker bar. If you can use a long pipe, you can gently break it loose. Try a six foot length and get a friend.

 

[Kestas]

There's not a lot of clearance under the truck for the DIYer to swing a cheater bar. It'll only work if the truck is on a hoist, otherwise the hydraulic jack method is needed.