[200q20v] Trans and Diff oils

[Tom and Carlyn Jervis]

This is not something to be done casually.  First of all, those plugs 
are very tight, and unless the wrench has the right tools, problems 
can occur.  You really need a 17 mm allen to put on a hefty breaker 
bar.

Second, and VERY important.  GL-4 and GL-5 (and GL-6) oils are very 
different.  Do not let anyone tell you otherwise.

Differences have to do with corrosion protection of copper (bronze 
synchronizers), anti-foaming, thermal and oxididation stability, and 
the relative important of high-torque, low speed, or high speed shock 
loading.  The tests are technical in nature and not easily described 
(and I don't understand them).  Part of the difference has to do with 
hypoid gears that have a very high torque loading.

It is true that GL-5 has more as well as different requirements than 
GL-4, but the numbers do not indicate anything other than the set of 
tests.  GL-6, for example, has no requirements for high-torque 
applications, while 4 and 5 do.

I have used Redline for the last 60,000 miles with no problems.  You 
can buy direct from them (800 #) and they know the amount and 
appropriate type for trans and diff for the 200-20V.  Audi uses 
synthetics and if you live anywhere cold, you should too.

Two stories:

In the way and far-off times I had an Alfa-Romeo.  Tranny ran low on 
a long trip right after I bought it and I refilled with (naturally) 
transmission oil at a convenient garage.  Shortly thereafter I had to 
replace all the (steel) synchronizers.  Should have used straight 
10W-40.

Once, after deciding that my urquattro would be better with winter 
dino oil in the trans, I had to be pull started at 20 below.  After I 
let the clutch out, the truck pulled the car along a snow covered 
street for about 50 yards before the wheels started TURNING! 
Synthetics are excellent at low temps.

Lesson:  Read the directions.

Tom Jervis
Los Alamos, NM
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