New boy on the block - Replacing the rear pinion differential oil seal on a 2008 1.8 Mx5 as it connects to the prop shaft

Technical Area Engine, Transmission, Exhaust etc
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  2. My model of MX-5 is a 2008 Mk3
  3. I’m based near: Ashford Kent
  4. I’m looking for technical help or recommendations on replacing the rear differential oil seal on a 2008 1.8 Mx5 as it connects to the prop shaft. The differential is a not a limited slip differential.
    My non expert advice received says that this should be straightforward by just marking the prop for position and then removed and then hook the old seal out and a drift a new one in. However, I am told that this is not straight forward and the differential needs to be rebuilt when the oil seal is removed or the diff needs to be replaced. Can anyone please provide me with some guidance. Thanks, Lakey
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The “locknut” securing the “companion flange” to the “drive pinion” also sets the preload on the bearings behind it and the “collapsible spacer” between them. Tools needed and torque settings specified for various points during reassembly.

Yes, it is effectively an out-of-the-car rebuild. There is more to it than simply replacing the oil seal.

See the manuals in various places online. Here’s a page from the Mellens version.

MX5 NC diffMellens fig13
MX5 NC diffMellens fig131800×2429 444 KB

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Thanks Richard,

Very helpful. I am also advised that rather than incur the cost of an expensive rebuild perhaps it is better to purchase a used differential from a reputable supplier.

Best

Lakey

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For information. Replaced the rear diff with one bought from Ebay. All seems good so far.