Differential Drain/Fill Plug Location

[Catbert]

During my first weekend spend with my CSi on a lift and inspecting it closely, I found a few things that made me question German engineering. Don't get me wrong. The more I look at this car, the more I like it!

One oddity is the placement of what I found to be one and only one differential plug. It is located on the side of the diffy and milimeters from the exhaust muffler. Thus, the only way to get an allen wrench to remove the plug and fill the diffy with new oil is to remove the muffler. Additionally, the only way to remove the oil is to pump it out. Why one plug and not two is a headscratcher.

 

[JMinPDX]

Zoom that photo out for a better view of what’s going on. Unless you have a different version of the side loader diff, The drain plug is easy it’s at the bottom if the diff. The refill plug is on the right side near the output shaft. The muffler at the rear of the diff should not be an issue.

 

[Catbert]

Zoom that photo out for a better view of what’s going on. Unless you have a different version of the side loader diff, The drain plug is easy it’s at the bottom if the diff. The refill plug is on the right side near the output shaft. The muffler at the rear of the diff should not be an issue.
View attachment 227812

Makes sense. I'll take a closer look later today. Thanks!

 

[HB Chris]

And below that drain plug on the flat boss will be two numbers which is the ratio and an S if it is locking diff. Your ratio should be a 3.25 which is 39 12.

 

[Catbert]

And below that drain plug on the flat boss will be two numbers which is the ratio and an S if it is locking diff. Your ratio should be a 3.25 which is 39 12.

I didn't see any numbers but will look again. Thanks!

 

[HB Chris]

They are stamped just clean that area with a wire brush.

 

[JMinPDX]

They are stamped just clean that area with a wire brush.

 

[Catbert]

View attachment 227816

Great! My wire brush and solvent will get some use tonight. Thanks!

 

[Catbert]

It seems the side where the numbers are stamped are covered by the muffler. I did find one number, 4280, but the AI wizard said it's just the build date. This is not important, only a curiosity.

 

[Ives]

Did you look on the passenger side of the diff? Don't always trust your "Wizard". We've seen what they can do to a video with a Coupe in it. Don't think your 4280 is a date too. If it's a stock diff that date does not add up to your Coupe.
Regards, Jon