29 replies to this topic

[dattoman]

Yes it should
Level should be checked at every service
And I would replace every 2 yrs myself

[dattoman]

Some have a drain plug
If not then you need to undo some bolts and pull the centre forward to let the oil drain out the gap
And refill thru the upper plug
If no upper plug... out with an axle and pour it down the tube
I think they hold about 1.5L
But it would pay to check that

[AbsynthHatch]

The bottom bolt on the carrier is a drain plug

There should be a fill point again on the carrier that you can undo with a quarter inch drive generally

Fill with appropriate grade oil till it starts to come out this fill point

Of course this will depend on the year and model the original diff came out of.

[ls2lxhatch]

Most 9" housings have studs for the centre and no drain plug. It would appear that Ford do not consider it necessary to change the oil. I had a drain plug fitted to my housing.

There is a filler plug in the side of the centre. The oil capacity varies depending on the housing, somewhere around 2.5 litres should see oil at the filler plug. If you have a LSD then you will need to use LSD oil.



You could pull an axle and drain the housing that way. If you are going to unbolt the centre then I would remove it completely and replace the gasket or use silicone to seal the centre.

Edited by ls2lxhatch, 28 March 2010 - 03:18 AM.

[dattoman]

You could pull an axle and drain the housing that way.

This might only work if your able to turn the car on its side... bit hard to get the oil out of the housing this way
Unless the diff if out of the car

[ls2lxhatch]

You put the body on axle stands and let the diff hang free. Then unbolt the shocks and remove the springs.

[rexy]

Due to the nature of contact between the teeth a diff filled with good quality oil requires changing almost never. This is the advice I have followed from several diff builders as well as a specialist in metal wear.
The oil in the nine inch in the daily is now 16 years old and all still sounds fine. Its had a fair flogging over the years too with plenty of power and sticky tyres.
By all means change it if you like when you first get the car as its an unknown from perhaps a cheap skate prior owner but after that I would leave it alone for at least 5yrs/100,000km.
I always use a heavy full synthetic oil.
R

[AbsynthHatch]

Again the center is attached to the housing with studs but the bottom one is not a stud but a bolt

This being the drain plug.

I changed the oil in mine last week.

[Heath]

If you have an LSD that is wearing down, or you've done some damage to any teeth etc, you will have crap in the oil. That will get in your bearings and on the faces of your teeth and damage the surfaces. If nothing else, your bearings will get nice and noisy.

A magnetic drain plug or just a magnet in the bottom of the diff housing (I used a Hard Drive magnet in my Banjo) should do a decent job of collecting ferrous material

But yes unless your diff is overheating (quite possible!) to 'break down' the oil, and there are no real contaminants, you shouldn't need to change the oil. Agree with the comment about if you don't know the history of the vehicle etc then change it.

[ls2lxhatch]

Again the center is attached to the housing with studs but the bottom one is not a stud but a bolt

This being the drain plug.

I changed the oil in mine last week.

There are no bolts just studs in the two 9" housings I have. I had the drain plug fitted when the housing was made.



McDonald Bros Housing

Edited by ls2lxhatch, 30 March 2010 - 01:24 PM.

[ls2lxhatch]

It may be that the car style housing has the drain bolt and the truck style housing has studs.

http://www.steeltech....com/FORD9.html

[AbsynthHatch]

I have drain plugs in the housing of my XW GT and both of my XY's

But the oil drain is the bottom bolt of the carrier in bolt in the 2 XB GT's and my XC Coupe but eh its not a McDonald Bros housing, or I didn't get these made so I suppose Ford must have

got it wrong,

[ls2lxhatch]

It sounds like Ford Australia at least got it right for the cars but for some reason the trucks (F100 etc) used full studs.

The truck housing is stronger and more commonly available at the wreckers therefore it is the basis for the majority of diff conversions. I had one housing built by John Taverna Chassis and one built by Final Drive. Both conversions used original Ford truck housings with full studs and no drain plug. I took the housing in the picture above back to Final Drive and asked him to put in a drain plug.

[Heath]

Yeah the Falcon housings I've seen (XB GT) don't have studs, but that doesn't stop you from putting a vertical drain plug in the bottom of the housing if that's what you want.

[AbsynthHatch]

If possible I reckon putting in a drain plug as Heath said is the best possible solution,

alot cleaner when changing the oil and with a magnetic plug alot more chance of picking up any metal etc

I agree with Andy to that the year and type of vehicle the diff originated from determines the different housing styles

[Marks LXTorana]

Has anyone tried removing the bottom stud and replacing it with a bolt to act as a drain, or is the stud screwed into a blind hole?

Also, are gaskets easily found (Supercheap, Repco, Ford dealer etc??) for the 9 inch centre? I want to swap mine over on the weekend.

[dattoman]

Get your diff made with a drainplug in it

And 9" gaskets should be easy enough to get

[mr5000]

as what datto said 9 inch gaskets are easy enough to get my mrs works at supercheap and her store stocks them

[Marks LXTorana]

Well Melbourne must have better stores than Sydney - the bloke on the phone didn't even know what a diff was. After explaining I then had to give a vehicle type that comes standard with a Ford 9", only to then be told they do not stock them. Then tried AutoPro that puts me through to a fax machine. Then tried a Ford Dealer who says it is a superseded item, try Rarae Spares. So I ring Rare Spares and they put me on hold and forget about me. So I ring a diff specialist who says to forget about a gasket, the only way to get a good seal is to use an oil resistant silicone like Dow Corning 732. Coat both faces, whack it in, tighten evenly then run your finger around the joint to remove excess.

Sounds like the way to go.

[mr5000]

oh dont think melbourne is special my mrs is up with most stuff from hanging round me shes got a vh with a worked 308 that we just built up and her friend that she works with has been around cars alot aswell on the other hand the manager at the store would do very poorly in an iq test the moron frOck noes how he got into a mangement position when he doesnt no shit about the cars nor how to use the computers