Rust and sludge inside rear axle - 1985 LR90

[bernie.g.suffolk]

I'm restoring a 1985 90 and am rebuilding the rear axle at the moment.  The diff oil was horrible - completly opaque and awful smelling.  Removing the stub axles showed that the interior of the axle was full of sludge and bits of rust (no bright metal).  I poured a litre of fresh EP90 down, drained that very well, at least getting some of the sludge my questing fingers dislodged.  Then I topped the EP90 up fully.

I really would like some advice on how to go about sorting this.  Do I need to get it cleaned out?  Shot-blasted?  Or will use and frequent diff oil changes sort it all out?

I haven't looked into the front axle yet - 😬

 

[92a]

Look for “Britannica restorations”  on YouTube he’s just done exactly this in one of his videos? 

[steve b]

Removing the diff and everything including the stub axles will show it's true state. A good pressure/steam wash would sort it or a 5" stove flue brush and plenty of brake cleaner by hand, finished off with a rag ball on a string to wipe any residue out followed by lots of oil checks and changes as needed. Replace all seals and check the seal lands for scoring while you're in there. 

Also clean the diff gear set then clean it again 

Steve 

[bernie.g.suffolk]

Thanks to both Steve B and 92a. 

Does the inside of the axle NEED to be rust free?

[Bowie69]

If chunky rust then it will come off and end up in the oil, harming stuff. 

A bit of surface rust likely isn't a problem. 

[bernie.g.suffolk]

4 minutes ago, Bowie69 said:

If chunky rust then it will come off and end up in the oil, harming stuff. 

A bit of surface rust likely isn't a problem. 

Thanks.  Another mucky job on the list!

[FridgeFreezer]

I'll add to this - buy a set of Nige's incredibly magnetic drain plugs - they will attract & catch any bits floating in the gear oil before they can get ground round the diff and cause damage.

If they're out of stock, normal fairly-magnetic drain plugs will also be better than nothing.

[steve b]

3 hours ago, bernie.g.suffolk said:

Thanks to both Steve B and 92a. 

Does the inside of the axle NEED to be rust free?

Yes - any free dirt/rust will damage gears and bearings . As FF says mag drain plugs are very worthwhile to collect any free metallic flakes but starting with clean internal surfaces is a must.

If it's off the vehicle and stripped bare you could take it to a local HGV yard - most have steam cleaners

Steve 

[Arjan]

Out of stock.....

Hope they'll be back in stock soon

[hurbie]

8 hours ago, Arjan said:

Out of stock.....

Hope they'll be back in stock soon

i think they will be in stock when he's returned from holiday ..... (everything is out of stock 😉  )

[Arjan]

Thank You !

[bernie.g.suffolk]

Here's a quick update.  I removed the diff and went to work with the pressure washer - it's a cold water washer but petrol powered, so has some power.  The rust isn't bad and is confined to the area nearest the stub axle.  I can deal with that effectively.  So panic over.

FridgeFreezer, thanks for recommending magnetic plugs - when they returm from holiday I'll pick up a few. 

 

Now onto other challanges!