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[johnnyboy]

Just a quick check...

Any recommendations on what oil I should put in the diffs (ie. both front and rear) of my 4.2l/258 1979 CJ?

I assume EP90??

And any views on whether to change it or just top it up (I don't think its ever been changed....).

If "change";
- how much do I need to buy?
- any opinions on synthetic vs "mineral"? or multigrade vs single?
- should I just take the covers off and let them drain, or should I do some sort of a "flush".
- Any tips or problems I should know about - or is it as easy as I think it is?


John

[Dave69]

if i remeber EP90,

no real need for multigrade as these are aimed at engines

no drain plug normally just pop the cover and dump into a container, the fill plug can be a pain as they do get mullered by previous owners using the wrong tools

if they havent been changed it might be worth doing for piece of mind, at least then you can see the condition of the diff and the oil taken out.  Fill back up until the oil starts to come out of the fill point

[Dave The Sparky]

I put 75-90 synthetic in mine but thats just personal choice.
If you are draining you will need some RTV or a gasket for re-assembly and once all the oil is out just run your finger under the ring gear as that's where all the metal seems to end up if something has gone amiss.
It will feel rough as the casting is rough but if there are solid lumps of metal sat there then its time to investigate further.

[5536paulj]

85/90 is what is required, 85/90LS if you have a limited slip

[Dave The Sparky]

So just to avoid confusion what we are all saying is sounds like any gear oil will do

(unless its limited slip of course)