Putting the Diff into Difficult...I mean differential

[Tinonline]

Hi there

Managed to clean and feed the leather interior over a few days. Now what next!?

Really it's time to change the diff oil despite the local dealership growing over it. But it's a mineral based fluid and even I know it doesn't last forever.

Armed with GL5 fluid and crush washers I jacked the car up and slid in axle stands. Boy there's little room and its claustrophobic wielding torch and bar. Both plugs were rusty and solid. So much so I couldn't fit a 10mm Allen key socket without WD40 and persuasion. Nothing undoing.

Time for a think. I ordered and collected two replacement plugs (one magnetic), for £13.19 from Lexus.

I'm going to have another more determined go, will remove the wheel for better light and access. My spirit level will assist in ensuring all is level whilst filling!

Difficult differential that's for sure! 😌

[ambermarine]

Simon

You will fare better if you use an impact wrench a Dewalt 18v will do the job but make sure you use hardened bits or the keyway will round.

If you overfill there is a pressure relief valve in the diff housing so excess fluid will leech out.

[Colin M]

Someone has rounded the keyway on the filler plug on mine ...

I have cut a hexagonal piece of steel the same size as the key that fits inside the keyway (10 mm) and am thinking of having it welded to the plug to see whether I can then remove the plug by using a 10 mm socket on the other end of the piece of steel. Has anyone tried this?

[steve2006]

29 minutes ago, Colin M said:

Someone has rounded the keyway on the filler plug on mine ...

I have cut a hexagonal piece of steel the same size as the key that fits inside the keyway (10 mm) and am thinking of having it welded to the plug to see whether I can then remove the plug by using a 10 mm socket on the other end of the piece of steel. Has anyone tried this?

I would be worried that the heat generated during welding would seize the plug in its threads, I would remove the old plug and replace it with a new one.

[Colin M]

Thanks, Steve, that is a concern, although it might be minimised by a tack weld, then allowing it to cool down completely and then another tack weld etc. This would prevent too big a build of heat whilst (maybe) enabling the hexagonal piece of steel to be welded sufficiently firmly to the plug to enable the plug to be undone. No guarantees but may be worth a try.

The only other alternative I can think of is trying a hammer and chisel on the edge of the plug in the hope that this might free it off. But again this has risks too. No easy solution, which is one reason why I have not done anything so far.

[cleverdick]

This reminds me of a thread on the forum of one of the Granada clubs some 15 years ago.  Somebody was stuck removing a sump plug, another member (claiming to be an aircraft engineer) put up a suggestion - that was dismissed by somebody else.... and the whole thing descended into a personal slanging match with threats being made!  It was famous at the time.  (That club is no more, I believe.)

But anyway, you might find that a gentle tap with a hammer on the plug itself is enough to break the bonds across the thread.  Plus, copious amounts of Plusgas (as opposed to WD).

I did mine a while back, and initially made the mistake of buying some fancy American synthetic stuff which was claimed to be the best diff fluid ever made etc. etc.  Well, guess what?  The diff was noisier as a result.  I went back to bog-standard Carlube hypoid gear oil and all was fine.

I found it useful to do a thing with a length of tubing and (somehow) supporting the bottle in the wheelarch.

Best of luck...

 

[Tinonline]

Yes I've heard a good tap breaks the seal. Also as advised to ensure fill plug is ok before drain plug is released.

Moral of the story is that clearly these units are not checked or maintained adequately? They should not be so stuck. Difficult maybe but not stuck.

[Colin M]

I have tried a few good taps to try to break the seal and used lots of plus gas but still no movement. Obviously difficult to get any movement when the internal hexagonal on the plug has been rounded off, which was why I was thinking of having a hexagonal piece of steel welded to the plug so some torque could be applied.

I hope not to get into any slanging match with anyone over this ...

[Tinonline]

Doubt it and trust not Colin, as this is a potential and sometimes used remedy. 

Tricky if not up on a ramp too.