Outer Limits 4x4 Board

Hello All,

Have just bought a '96 Sierra and have given it a bit of a service today. However, I wanted to change the diff/gear oil but am unable to undo the filler plug. The filler plug looks like it needs some kind of square allan key to undo it but I could not find such a tool today.

Can anyone tell me what tool I need and perhaps where to buy one?

Many thanks.

you need a 1/4 inch driver. the square bit that you put your sockets fits the hole. be careful though as drain plugs tend to be pretty tight and have a habbit of rounding out. the best way I have found to do it is with an air rattle gun.

It is not 1/4" it is 3/8"

If you use a rattle gun make sure it has an extension on it - do NOT use the snout off the end of the rattle gun. These usually have little circlippy like springs on the end and rounded edges to make removing tools easy. This will burr out the (shallow) hole in the fill plug in no time.

The best way to go is to buy a 1/2 to 3/8" drive adapter and grind the end down so it is nice and sharp. this will seat snugly in the fill plug and then you can lean on it with a big 1/2" drive breaker bar. It will come undone a treat like this.

Often the fill plugs have been burred out by clumsy mechanics with a rattle gun. (not implying anything Sam) These will sometimes not come undone so the way get hem is with with a cold chisel. Once they are off you can weld a 14mm nut onto the plug and its apples.

yea what Gwagonsteve said. 3/8 (i wasnt even close )

Yeah....I have the same problem, mines slightly rounded.....haven't been able to get my filler plug out for ages

....had to dribble oil down the breather

Squik wrote:Yeah....I have the same problem, mines slightly rounded.....haven't been able to get my filler plug out for ages

....had to dribble oil down the breather

Well that is how I fill mine.

Also fill gbox thru gearstick hole for same reason

christover

How do you get your levels right using this method

If it is too rounded and you cant chisel it out, next time you have the centre out (so you can clean the shavings up) try drill a hole through the filler plug and use an easy out. just make sure you have a replacement plug first.

just cruizin' wrote:How do you get your levels right using this method

I use the capacity listed in the owners manual and/or workshop manual.

The capacities are in the bible methinx, too.

I not sure about 1.3 diffs, but my 1.0 litre front has 1.3Litres, so I put in 1.5 to allow for what leaks out and rear is 1.0L I think, but my rear plugs ok.
I think the gbox is 1.3 or 1.5 litres?

christover

we just did 2 zooks a little heat from hand held blow torch cheers ron

A FRIEND ONCE TOLD ME TO USE A GOOD PAIR OF VICE GRIPS AROUND THE EDGE OF THE PLUG.##CK ME IT WORKED.

All,

Well many thanks for the quick and detailed replies.
This morning, using the 3/8 drive, I was able to remove the drain and filler plugs from the rear diff and change the oil

As some of you have already pointed out could happen, the filler and drain plugs on the front diff are rounded and so I have as yet been unable to remove them. Will give it another go next weekend.

Thanks again!

we welded a nut on and un did it that way cheers ron

Welding a nut on with the plug in the diff will melt the nylon washer that sits under the head of the plug and stops it weeping. It is best to chisel it out, remove the washer and then weld the nut on, replace the washer and then put it back in the car.

Take care when chiseling though as the axle housing is only marginally thicker than a Range Rover one and it isn't hard to push the housing in a bit. Shouldn't be too big a problem, just worth looking out for.

It is a bit of a PITA do so the front as the tie rod is in the way.

Steve.

i pull the cv and poor it down the axle tube

20 cent washers at bunnings no worrys hot/cold tap washer