Changing my differential gear oil...

[Chiketkd]

Well, I'm heading back to the 1/4 mile dragstrip this coming weekend, so as my last piece of maintenance, I'm changing my front and rear differential gear oil tomorrow am before work.

Did a search and most people mentioned that the front diff drain plug takes a 17mm wrench - no way!

Tried a bunch of wrenches on it at the parts store and a 13/16" wrench was the perfect fit. That's right, an SAE sized wrench!

Anyway, I picked up two quarts of synthetic gear oil and I have another quart sitting at home. I've also rotated my tires and adjusted the pressures to 40/36. My engine also has new motor oil pumping through its cylinders.

Guess I'll soon be all set for Saturday...

-Chike

[lee]

Sorry about that (me being one of the 17mm people). 13/16" means its either 20 or 21 mm. So that means one of a couple different things:

a) Subaru changed the size of the plug on different years/models of the SVX (mine is a 92 LS-L).

b) I have a very bad memory and it is 20 or 21 - in which case it has to be a 21 since I don't have a 20mm wrench or socket (and only have a 21mm socket - I could swear I used a wrench last time, but...).

c) You (or I) have a non-OEM drain plug.

d) make up your own excuse & insert here.

again, sorry for the bad advice.

[Chiketkd]

Lee,

Don't worry about it. When I did a search, a couple of other people went from memory and thought it was a 17mm as well.

What's interesting, was that when I was at svxfiles' place he mentioned that all front diffs for the SVX used an SAE sized wrench as well. I know Subaru uses a lot of Nissan parts on their cars, and I almost wonder if the front diff is a part that Nissan Motors sells to some American car manufacturers?

The 13/16" wrench was a perfect fit. I tried a 20mm and it was too small, and the 21mm would work, but was a little oversized. Kinda weird that our cars have an SAE drain plug while everything else is metric???

-Chike

P.S. Thanks for your advice on the rear drain plug Lee!

[NeedForSpeed]

Originally posted by Chiketkd
Well, I'm heading back to the 1/4 mile dragstrip this coming weekend, so as my last piece of maintenance, I'm changing my front and rear differential gear oil tomorrow am before work.

Did a search and most people mentioned that the front diff drain plug takes a 17mm wrench - no way!

Tried a bunch of wrenches on it at the parts store and a 13/16" wrench was the perfect fit. That's right, an SAE sized wrench!

Anyway, I picked up two quarts of synthetic gear oil and I have another quart sitting at home. I've also rotated my tires and adjusted the pressures to 40/36. My engine also has new motor oil pumping through its cylinders.

Guess I'll soon be all set for Saturday...

-Chike

Have fun! Can't wait to hear about your day.

[SVXRide]

Chike,
Were you planning on trying different "launch" approaches this time?
Have fun and don't break anything!!
-Bill
p.s. you know, stiffer springs should help the tires "plant" better off the line

[Chiketkd]

Thanks Bill and Ron! I will have a full write-up with pics as soon as I get back. I plan on making two passes and then heading home.

I'm feeling more and more confident each day about the durability of my car. The trans is super tough and the Legacy R180 rear diff seems to be holding up very well to hard launches.

Stiffer springs will help, and Mychailo's 1/2" lowering springs are on my 'must have' list of mods to get in the future!

-Chike

P.S. One interesting thing, I found a way to convert my 1/8th mile time (10.10 @ 69.77mph) into an approximate 1/4 mile run and got roughly a 15.77 @ 88mph which seems about right. After seeing Chris' post about improving his times in Canada by 0.7 due to the lower altitude of the track, I went to the NHRA website and found the follwing conversion formulas: NHRA Correction Factors

Plugging in my approximate 1/4 mile time from my last outing (and correcting for an altitude of 3000ft), it returns a corrected 1/4 mile of just under 15.2 @ 91+mph! And that's in 80* weather. Temps on Saturday in Richmond should be in the 75-80*, but as the track is just 100ft above sea level, my times should be faster. Here's hoping...

[Chiketkd]

Originally posted by SVXRide
Chike,
Were you planning on trying different "launch" approaches this time?

Bill,

I've raised my tire pressures to 40/36 and the best times in an auto trans AWD car are returned by launching as high into the rev range as possible. Since the stall speed on our cars is ~2500rpms, that'll be where I'll launch from on Saturday. I plan on leaving my gear selector in 'D' to have the TCU shift at 6500rpms down the track...

-Chike