Maintenance questions

[SD_GR]

I read some places that you should put some type of sealer or lok tite on the threads.

No. Think about this. You're working with an Al head and you are removing the plugs every 60K miles. Anti-seize makes sense, since, well, you do not want the plugs to seize onto the head. Loctiite will do the opposite of what you want.

I'm trying to find more info on the LSD fluid for the rear diff and am reading about LSD 90 but it may seem like people are using it only for the STI. Others say to use the 75w-90 in the rear.

What people say doesn't matter at all. The only thing that matters is what Subaru specifies. For the WRX they specify 75W-90 GL5.

[wasisnt]

I meant anti seize on the threads of the diff drain plug, not the spark plugs

I also read that you use the LSD for STIs only since the WRX has the LSD components sealed inside the diff.

Normally I would listen to the dealer but sometimes they have no clue it seems.

[SD_GR]

I meant anti seize on the threads of the diff drain plug, not the spark plugs

My apologies.

For the diff drain, Subaru specify a silicone sealant that is hard to find. Some people use nothing, others substitute something readily available locally etc. Here's my take from a while back:

http://www.clubwrx.net/forums/1384930-post4.html

See the full thread here for more info:

Tranny OIl Weight