Diff key mounting holes "how to"

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Well-Known Member
Below is a picture of a diff key in my grubby hands, I will show you where to drill the chassis for the install.

From the back of the chassis scribe a line across 75mm as shown.
The hole that the diff gear comes through, measure 6mm from that edge and scribe another line (that intersection is your first hole).
From the first hole scribe another line 20mm apart (that is your second hole).

I used a 2.5mm drill first to ensure the bit did not move when trying to start the hole.

The final size hole is 4.5mm, you then need to countersink the chassis so the screws sit flush.

This was done with a stock set-up. Factory fitted diff & diff cover.
After I assembled the car I noticed some very slight rubbing as the diff cover is not machined & is not 100% round / true. A quick blast up and down the road should take care of that.
If you have a heavy duty diff sleeve/ cover, you might want to position the hole further back.

Good luck.
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