Hi Guys,

Can anybody tell me if changing the fluid in my '93 520i auto gearbox is a viable DIY job. If so, any tips would be aprreciated,

Thanks

Paul

Changing the tranny fluid is easy but you should really drop the sump to properly change the fluid and as Andy K says change the filter.  It is extremely worthwhile.  I did my sump on my Vx 3.0i 24 v Senator.  I have yet to tackle it on my E39 steptronic 523i SE. 

You wouldn't let your engine oil go 50,000 miles between oil and filter changes would you so why let the tranny fluid do the same.  The newer E39 auto boxes are sealed for life but I wouldn't like to see one not get serviced or at least have the fluid and filter changed after 50k

Not enough people change their tranny fluid then wonder why after 120k miles their gearbox goes **** up!

Take the car for a run so that she is fully warmed up and drain the oil from the tranny sump when she is still hot so that all the crap is still in the fluid and gets carried out when you drain it. 

Screw the sump plug back in and then drop the sump.  There will still be some fluid (and it will be hot too!) in the sump even though you have drained it so be carefull when you lower it from the tranny block.

The filter should be a big flat rectangular plastic thingie I would imagine.  It will be held on with a couple of not very tight bolts.

Make sure you fit a new filter gasket, some filters will come with a gasket some don't.  Also make sure you fit a new sump gasket.

As Andy K says make sure everything is clean.  I did mine in the driveway with no probs.   Cost nearly £100 though.  Filter was £50 from Vx, gasket about £10 and 5 No. 1 litre bottles of Castrol Dexron TQIII fluid at £6 a litre.  Can't buy a gallon of tranny fluid had to buy it as 5 bottles of 1 litre!

I presume you have a dipstick tube to fill her up with. 

Make sure you measure how much fluid came out so you can check against the specs to see if you are losing any.

My E39 has a sealed for life tranny box apparantly but know one can tell me (yet, have just posted a query) how to check or add more tranny fluid.

Andrew