QUESTIONS: Changing ATF, oil, and diff oil
 

OK, folks, I'm set to spend part of my 4th of July weekend under the SVX. I have a few questions.

Motor oil: I'm adding a Fumoto valve and switching over to synthetic (Mobil 1 10W-30) and a K&N oil filter. The former owner's husband told me that he put in synthetic some of the time, so I am hopeful that I won't see too many leaks. Amsoil, which makes an engine flush-in-a-bottle, recommends flushing before switching to synthetic. Red Line, which does not make a flush-in-a-bottle, says it is not necessary to flush the system. I don't want to dump any old harsh chemical brew in there, and I can't find anything better than "Gunk." Should I skip the engine flush and rely on Mobil 1's detergent mix to clean up anything that needs cleaning?

ATF: I'm going to drop the pan, change the internal filter, and add an external filter and a tranny cooler before filling it with Red Line D4 ATF. I plan to drain according to Amsoil's 12-step instructiosn, which sounds like it will get at quite a bit of the old ATF. I don't know for sure what the previous owner had in there before, but I assume it's dino ATF. I was planning to pick up some Lubegard ATF Flush last night, but the NAPA store that told me by telephone that they had it turned out not to have it. Here's my question: Should I stop worrying and take Red Line's advice (in other words, skip the flush-in-a-bottle step)?

Diff oil: I'm confused. :confused: When I ordered my Red Line ATF, I also ordered a quart of the Red Line 75W-90 gear oil for the rear diff. The front diff, however, calls for 80W90, which Red Line doesn't offer and which I can't find in synthetic locally. (I don't want to pay $9 in shipping for $18 worth of Amsoil or Royal Purple synthetic 80W-90.) Should I go with dino 80W-90 or change to a different viscosity grade (75W-90) in synthetic? Or should I just stop whining about the cost and get the Amsoil or Royal Purple diff oil in the recommended 80W-90 grade? Hey, I said I was confused!

Are there any other fluids I should be swapping out while I am getting greasy under my new-to-me 1996 LSi with 76K miles on it?

Purolator "One" oil filters are probably better than the K&N oil filters. In the test that I saw, the Purolator was well-built and filtered out smaller particles than any other filter in the test.

Don't worry about the weight of the gear oil. 75W-90 is hardly any different than 80W-90.

If you haven't already done it, I'd suggest replacing all the brake fluid in the brake lines. At 85k miles on my SVX, the brake fluid was getting pretty dark. Replacing the brake fluid will help minimize corrosion in the brake system. Dot 3 or 4 brake fluid is fine. Don't try to use the Dot 5 stuff. Its easiest to do the brake fluid replacement if you replace the original brake bleeders with speed bleeders. Then you can do the job faster and by yourself.

Jonathan,
Pardon my ignorance, but what's a "Fumoto valve"?
-Bill

it is a small valve (ball type) that you put inplace of the drain plug so you don't have to wrench it anymore. Also you can put a hose on the end of the valve and keep the mess to a minimum. Cool deal.

May want to do the power steering and coolant while you're under there.

If you're doing the brake fluid, DOT 4 has a higher boiling point then DOT 3. However, do not mix them together. Stay away from DOT 5 - silicone base - if you mix it with DOT 3 or 4, you'll have a hell of a mess to clean up (kinda like coolant in your oil - bad news).

If I recall correctly, the power steering fluid isn't really power steering fluid ... so double check before putting anything in there.

Like oil, all the fluids break down over time and don't do their jobs so well - but most people forget about them until there's a problem.

The lubricant used in the Power steering system is Dexron3. :)
And DOT 4 brake fluid is a safety upgrade that costs next to nothing.
Just bleed out the old and fill with the new.

Although it isn't mixable with DOT 3 so personally I'd stay away unless you can come up with a way to evacuate all the Dot 3 and then install dot 4 which is easier said than done. You can get very good DOT 3 with Valvaline Synth. (tan/gold bottle) which has a very high boiling point and is very cheap to buy. So long as you keep your fluid water free and aren't on the track 5 hours at a time you'll be happy with it.

If you were going to flush you should consider Auto-Rx (www.auto-rx.com - for engine oil and www.auto-rx.net for tranny fluid). The flush is less to clean out (Mobil 1 will do a remarkable cleaning job), it's more to condition the seals. Dirt & used oil collects behind the seals forming a "gunk" that helps the seal to do its job. Mobil 1 will clean off the gunk and if the seals are marginal, they WILL start to leak...if the seals are in good shape, then no issues.

FYI, there are basically 3 types of synthetic on the market.

PAO - Mobil is the foremost and top-of-the-line producer of this product (no other company that I know of can seem to manufacture the product with the spread of viscosity that Mobil achieves while still meeting jet engine specs).

Ester - various chemical companies make it, all about the same as far as I know.

Hydro-cracked dino - wasn't considered a true synthetic by anybody except Castrol until after a lawsuit by Mobil challenged the claim and a European court ruled in Castrol's favor (this is sometimes know as a type III oil). Today many brands claim a synthetic oil, but belong to the type III category, a case of jumping on the synthetic bandwagon for the sake of profit - type III is much cheaper to make.

Also, AMSOIL was (is?) basically a reformulation of Mobil 1 (a PAO base stock). Redline and Neo use a lot more ester in the base stock, and so are less subject to seal leakage (pure ester base stock will overly swell the seals and cause a rupture from that direction, so they use PAO too, just less than AMSOIL or Mobil 1).

Are you sure about this? I've been under the impression that DOT 4 was backwards compatible.

I do know DOT 5 is not compatible with any other brake fluid and requires a complete flush and replacement of all rubber parts before usage.

What about DOT 5.1 ? It's supposed to be compatible with DOT 4 and a lot better. Anybody tried it?

Beav, I don't think it is every brand. My point is if you aren't reaching the limits of Dot 3 even Dot 3 that hasn't been changed every 2 years like it should be, you don't have a need to go elsewhere. Heck our racer still has 3 in it and hasn't had any brake fade issues to date

I agree, DOT 3 is usually adequate for most applications, but you know how perception works in the marketplace.

The DOT standard for brake fluid does not vary by manufacturer, so 3 is 3, 4 is 4, etc. Compatibility is paramount with DOT standards AND MilSpecs.

I've no experience with 5.1, as stated DOT 3 works just fine.

And most of them say they aren't compatible with other manufacturer's fluids. :eek:

Re: QUESTIONS: Changing ATF, oil, and diff oil
 

Lee,

I hope you still read this forum. I have read your postings on this forum and have learned much from them. I have also spoken with the oil people and, of course, the ATF people don't suggest using an additive and the people at Lubegard do suggest it. The folks at Redline suggested their D4 product for the SVX and were worried that the Lubegard could cause the fluid to be too slippery and cause excessive seal swell. The folks at Lubegard semi-agreed in that they suggested against their HFM product in the black bottle as it may contain too much friction modifier. However, they insisted that their product (they suggested the red bottle) only conditions seals and does not swell them. Lubegard also claims that their additive could decrease ATF temperatures by as much as 40F. I also know first hand that the red bottle is very good at keeping the clutch plates in Subaru center differentials from binding. So, I would think seal conditioning, lower operating temperatures and protection against differential binding would be a good thing. I am leaning towards Redline D4 with Lubegard in the red bottle.

On the topic of oils, I read something that implied that ester based products have more cleaning power than PAO based oils. Is that true based onyour knowledge? As such, I would think using Redline and Royal Purple would create an even stronger need for seal conditioning and maybe some amount of seal swelling to prevent leaks.

Re: QUESTIONS: Changing ATF, oil, and diff oil
 

I check in from time to time - mostly to see who is still around.

I think my oil knowledge has become OBE - I understand Mobil 1 now has type III oil in the formulation, etc.

I would consider asking over on bobistheoilguy forum. As to slipping bands and clutches - I haven't kept up, has the community decided that the SVX tranny failures were due to slippage or being undersized/cooled. I was always under the impression the failures were due to cooling issues, not slippage. If it was slippage, then I would be hesitant to add much in the way of an additive. If it was a heat due to inadequate cooling for the load, then an additive might help.

Either way I'd probably find out the current state of the art over at http://www.bobistheoilguy.com

Lastly, my apology for jumping into something for which I'm pretty far removed, especially when compared to the current owners.