Checking differential oil

[quee2646]

Hello,

This is the first time I will check the differential oil. Do I need a special tool to undo the filler cap? It looks square. Or is there a knack?

Thank you

[StillGotMy1stCar]

The plug size is 7/16 square
ESM do a tool Part No ACC097 or you could make your own as I did by grinding down the 1/2 male sides of a 3/8 drive female to 1/2 drive male adaptor, £2.75 eBay.
Draper do an 11mm adaptor Part No 38322 but may be a loose fit, others will be along soon to comment.
Regards John.

[philthehill]

As the square hole in the filler/drain plugs are tapered a 3/8" 'T' bar or ratchet is more than sufficient to undo/do up the drain/filler plug.

[mogbob]

As a first timer , clean around the drain plug with a bit of rag / kitchen paper / whatever before removing , so no dirt gets in. Lay a few sheets of newspaper / oil drip tray / ice cream carton underneath the drain plug. If you're jacking the car up , for easier access , chock the front wheels so they don't move and put the back of the car on axles stands , level ground not on a slope.

Use a small plastic funnel if a plastic tube isn't supplied with the oil plastic carton. Put on plastic / vinyl gloves to protect your hands.Fill slowly, until it " just " dribbles out of the threaded hole. There is no point in rushing it , if you tip it in , rather than pouring slowly , it will reach the "full " point and spew oil everywhere making a lovely mess. Remove the tube or funnel , catching the drips in the rag / paper and wipe clean around the hole.
Replace the plug and do up firmly.
If you where doing a full drain and refill , then take the car for a little run to get the oil warm and fluid , to aid draining. A suitable size
receptacle for catch all the old oil is required. Spread a bit more newspaper around. Important that you remember to refit the drain plug.

( I forgot when doing an engine oil change , for the first time. I couldn't work out where all the oil was going. The amount I'd put in was way over the specified capacity for the engine. I looked at the garage floor and found my own private oil slick !! Stupid boy , putting the drain plug back , before refilling , would have been a good idea. )

Dispose of the old oil , either at your local council recycling centre or your local friendly garage if they are amenable. NEVER down the drain !
If we're clever , we learn by our mistakes , if we're " man enough " we tell others of our stupidy so they don't make the same mistakes.
Bob

[myoldjalopy]

Perfect description from Mogbob, and good advice not to rush it and cause an oil overspill! Don't bother with the tool from ESM - it is a poor design and the bend in the bar is too far out from the end that fits in the plug to get good leverage on it. As Phil says, a 3/8" rachet will do fine.

[quee2646]

Thanks all for your advice--I've picked up a 3/8 T-bar from Halfords.

And thanks, Bob, for your detailed instructions. I'm a skinny runt so I can get under there without jacking it up.

[StillGotMy1stCar]

As the square hole in the filler/drain plugs are tapered a 3/8" 'T' bar or ratchet is more than sufficient to undo/do up the drain/filler plug.

Phil, I had to double check, a 3/8 drive in my plugs doesn’t touch the sides and a ½” drive nearly goes in. Must be a late van/pickup thing, be interesting to know if others have this.
Regards John

[Boomlander]

I used a drain plug multi tool that I bought years ago (Lots available on Ebay) and after grinding a small amount off the length of one of the tapered bits it fitted perfectly.

[philthehill]

There must be some variance in the size and depth to the filler/drain plug central square hole as I have just tried a 3/8" drive socket bar in the square hole of the drain/filler plugs fitted to my 1098cc axle case/4.55 diff and whilst it does not tightly fit the holes (& it will not do so as the hole is tapered) it provides sufficient grip to enable the plug to be undone without damage to either the drain/filler plug or the socket bar square end.
The square hole must not have any crud in it as the 3/8" socket bar needs to be right at the bottom of the hole to work best.

Fitting the ESM drain/filler plugs with female allen key facility may be the way ahead.
http://www.morrisminorspares.com/rear-s ... al-p831251 and is no more expensive than buying the ESM drain plug spanner http://www.morrisminorspares.com/rear-s ... ug-p831301
Phil

[myoldjalopy]

Of course, it could be that the recess in the plug has got worn out of shape by some previous, ham-fisted 'mechanic'..........

[simmitc]

All above is excellent advice, only thing to add is that the plugs, if not removed for a long time, might be tight to remove, so after cleaning run some releasing fluid over the threads prior to attempting to move. Interesting findings about different size holes - all the ones I have ever seen have accepted a 1/2 inch drive - on a couple of occasions I even resorted to an air impact wrench to loosen the plug. The allen key option sounds like a much better idea than the tapered fit.

[dawpooldad]

Hi
I agree with all the above but would like to add a comment about the type of oil used.
See this https://www.mmoc.org.uk/Messageboard/vi ... il#p604215

I recently had probs with the diff (See "Diff Ratios" Post above) and I there's a possibility that I had the wrong oil in it which might have degraded the ball bearing retainers.

Regards

dawpooldad