[cchas14]

I am tring to locate the access bolt for my rear end. I did find a bolt that looks more like a plug than a bolt. It is located on the passenger side and half way between the "Pumpkin" and where the drive shaft connects. Can someone tell me or show me on a photo if this is the correct bolt/plug?

 

[Crawdaddy]

that's the location for the fill plug on the 10-bolt GM rear end. It has no drain plug. To drain the differential, you have to pull the back cover. Pretty simple procedure and a new gasket costs about $10.

 

[cchas14]

So,if I need to check the fluid I just open that plug? It Looks like all I need is a 1/2 extention on a ratchet.

 

[GaryL]

Yes, pull the plug. On level ground the oil level will be at the bottom of the hole.

 

[Hummer]

If you want to do a little work you can drill the lower flat portion where the drain plug USED TO BE and tap it with 3/8" high pressure pipe plug thread and install your own drain. I have done this on several vehicles and is not that big a deal. My buddy put plugs all over his Jeep drive train.

Note: when you start to tap go in a little and try the plug as you go. You want it to snug up when the top of the high pressure plug is even with the housing. Won't hurt to wrap it in teflon pipe tape when you run it in.

I am thinking about doing this and replacing with synthetic gear oil and forget it for 250K on the Ho I just picked up. Synthetic grease will hold up much longer than conventional grease.