A Novice Tranny Question...

[Soul Shinobi]

It's worth noting that my Subaru Legacy (5MT, N/A) is the beginning of my car learning experience, and that I've had it for less than half a year.

Well, just the other day I was changing my oil for the second time ever (and making a god dammed mess of it) when I discovered the dipstick on the tranny. The fluid level was low, a bit below the low mark. Again I was changing my oil at the time so my car was on level ground and hadn't been run for a good few hours.

My first question is, should I just top it off, should I change the fluid, or should I let my mechanic mess with it? I'd like the have it changed so that I know there's new lubricant in there, but is that something I can do myself, or should I let my mechanic handle it because I can't even change my oil with making a huge freakin' mess? If you think I can do this myself, then what brand and weight (if there are even different weights) lubricant should I use?

I read here in my Haynes manual for the car that the fluid measured by this dipstick on manual transaxle models (like mine) is shared with the front differential. If I were to get the transaxle fluid changed then I'd also have the same done to the rear diff, just so all my fluids are on the same page.

The more information you can give me the better, I'm eager to learn.

[rallysam]

If you are not a fan of oil changes, the gear oil is more of a pain. I mean people will say it's easy and anyone can do it, which is kinda true, but it also takes more patience and is more prone to errors.

If you do it, don't rush it. Don't have anywhere you need to go that afternoon, otherwise you'll end up rushing it and causing wear and tear due to filling to the wrong level.

Make sure you are on super level ground to get a good measurement from the dipstick. Being level is more important for the tranny dipstick because it sucks. (b/c I think the gear oil lies more shallow and horizontal than the engine oil pan, so it is much more sensitive to a slope making it all run to one end giving you the wrong idea of fullness).

Be really patient about adding a little bit, waiting for it to settle, then doing a good measurement with the dipstick. Each little top up takes forever because gear oil moves really slow and the dipstick is not very good.

If you drained it down, then you'll need to drive it around after you've completely refilled it to re-coat the gears. Once you've filled, driven, parked, and waited for it to settle again, you can repeat the painfully slow process of topping off.

Every time I've done it it's turned into a fiasco because I am supposed to go somewhere else later in the afternoon, so things start getting rushed at the end and I botch it. It takes a lot of patience to not over fill it (causing tranny oil to spew on your exhaust manifold and make your car smell like rotten eggs) or under fill it (causing your tranny to make bad noises).

If you spill a lot of engine oil, you'll love this because gear oil stinks like hell. Also, Subaru was mean enough that the fill hole is also the dipstick hole, meaning you have to keep pulling the funnel out and spilling. Plus, it's right over the exhaust, so any spillage burns off and smells bad.

[Soul Shinobi]

Okay, this is some great info. I'm sure my reading was accurate as my garage is quite level (I just checked with a big bubble level right now to be sure) and the car was off for at least an hour at the time I checked it.

Truth be told I am a very patient man and enjoy much changing the oil. The reason I made such a mess was because I let the engine run before draining the oil to stir sediment and drain easily. It came out like it was water, too fast for it to pour into the hole on the side of my collection bin.

So, the question is, do you think I should just add a little bit (if so is there a certain kind or brand of gear oil you think I should use?), or should I have my mechanic drain it in March when he has to inspect the car anyway (in which case I'll have him drain and fill the rear diff too so the I know everything is in equal working order)? I don't think I'm up to draining it myself, I don't even know if the local landfill has a place to dispose of the old oil (I think they only take engine oil).

How often is tranny/diff oil even drained and filled? Once a year? Every two years?

[rallysam]

I don't have my manual with me. You can check the service schedule and recommended viscosity. You don't have to change it very often at all, but odds are that the old car is due for a full change. You can try whatever grade the manual recommends, you you can also try "Scotty's Tranny Cocktail". Some people swear by it for fixing slow synchros, I've never tried.
http://bbs.legacycentral.org/viewtopic.php?t=27436

[Soul Shinobi]

A week or two ago I found the full service manual (1,427 pages, six sections) online (unfortunate for me it seems to be the European version, but most things are the same anyway). Recommended gear oil is GL5 85W for my applications or 90 if the temperature doesn't get below freezing (80W if you live someplace really cold that doesn't get above 75 degrees F). That's for both tranny and rear diff, manual cars.

Reading into that link and subsequent links therein I'm getting pretty excited to use this Scotty's Cocktail, and I'm getting excited to do it myself.

I pulled my car into the garage to see if I could get to the tranny drain plug without jacking the car, and being as sleight as I am I could. It's a damn mess ender there though. The service manual recommends using a gasket between the plug and the tranny, but the plug seemed flush against my tranny. I wonder if that's what's caused it to leak? Can I use a oil plug crush washer for this if I do it myself? I think I will...

Running all this trough my mind again, I'll post more if I come up with any other thoughts.

EDIT1: As for whether or not to use Scotty's Cocktail, I might if I like what I continue to read on it, if I decide not to I'll just go with Castrol GL5 85W for everything, unless you recommend something else.

EDIT2: Hmm, a lot of people seem to use lighter than recommended gear oil.

EDIT3: I wonder if the cocktail would be too light (thin) for the age of my car (255,000+ miles)...

[Soul Shinobi]

Okay, I private messaged Uncle Scotty himself asking him what I should do. He said I should ONLY use Castrol HypoyC 80w90 for the tranny and that it'd be okay for the rear diff too. He said that for the very high mileage of my car this would be best and that his cocktail would be a crapshoot that could either cure or kill my tranny.

[rallysam]

Interesting. I dunno if that info is in the thread I posted earlier. If the info is not in there, maybe you should post it, because a lot of people on this board have high mileage cars.

[Soul Shinobi]

Yes, I think I'll make a topic showing the correspondence between Uncle Scotty and I.

[Soul Shinobi]

Hmm, I asked him if it was okay for me to post his messages. He said he'd rather not have me show his name because he wouldn't want others to be encouraged to PM him with questions. His name is what would give such a post authority, so I think that instead I'll do what he suggested, then I'll post with my experience and mention in passing that he recommended it.

[isotopeman]

On changing the oil. It can be done rather easily without spilling a drop of it.
What I do is break the plug loose with a 17mm (six-point, but that doesn't matter) socket on a short breaker bar. Once it's loose, I turn it slowly with my fingers while the catch pan is underneath. When I think it's almost out, I turn the plug while pushing in on it. You can tell when the plug is all the way out, even while pushing in on it, once you feel where the threads overlap and kind of click. Then I pull the plug out holding it from the top. Not a drop of oil on either myself or outside of the pan.
Latex gloves are also great (and cheap) for wrenching with.

[Soul Shinobi]

All well and good. That sounds like a great idea, it's good to know it's well enough made that I can do that, and I'm good with my hands too so it should work out well. My father is a retired dentist and he gave me a box of synthetic gloves upon request. They're nitrile, even stronger and more chemically resistant than latex.

I have a torque wrench the head of which seems to measure 12 or 13mm and I do believe the tranny bolt has a square hole in the middle. I think this will fit, as it does fit into the rear diff bolts. Also, I've purchased the propper Subaru OEM Three Bond 1105 sealant for the rear diff bolts here.

Oh, back to a previous question of mine, the "gasket" on the tranny bolt, can I use a oil plug crush washer?

[AWD_addict]

Oil plug crush washer should work, they are both 17mm IRC.