idosubaru Posted June 14, 2006 Share Posted June 14, 2006 I honestly think that these Subie trannys are so well-built that it really doesn't matter if you use dino or synthetic fluid in 'em. with the exception of the SVX (and arguably the old school 3AT) subaru auto transmissions are very reliable and not prone to many problems. except torque bind of course and that's reasonably addressable in most cases. i've had very few problems with my now approaching 20 year old auto transmissions in my XT6's. i've only replaced one with 150,000 miles and it took a beating from me before i knew much about cars. all in all, subaru auto trans seem fairly solid...for an auto trans of course! Quote Link to comment Share on other sites More sharing options...
nipper Posted June 14, 2006 Share Posted June 14, 2006 Nipper and I have gone around more than once on this issue. He's a strong believer in std "dino" AT fluid, and I'm as strong over in the synthetic camp. IMHO, which is supported by my buddy the chemical engineer who works in the oil industry, synthetic AT fluids are the same viscosity (i.e. the same amount of "sticky") as the dino types, but they keep that characteristic over a wider operating temp range, and they don't change chemical composition as fast as dino oil does when they're subjected to long spells of high heat. That's why synthetics are better, especially if you pull a heavy load and heat up that tranny more than the casual Sunday driver. I've run with synthetic for a while now, in a 10-yr old OBW that had nothing but dino oil in it until the clutch pack seized up from torque bind. I tried a straight flush and fill with synthetic at first, which didn't clear the binding completely, and I eventually replaced the clutch pack and re-filled, again with new synthetic. I've run nothing but synthetic in there ever since, and the tranny is performing flawlessly. I honestly think that these Subie trannys are so well-built that it really doesn't matter if you use dino or synthetic fluid in 'em. Just keep whatever is in there clean and change it according to the recommended interval, and you'll be fine for many thousands of miles. Of course, YMMV! i thought we compromised on the hybrid oil, or did i miss that memeo? nipper Quote Link to comment Share on other sites More sharing options...
nipper Posted June 14, 2006 Share Posted June 14, 2006 So what do you recommend for ATF fluid for my 2000 Outback.Is the trans drain plug easily accessible? If you want synthetic go ahead, but if your tranny acts weird you need to change back. On the other hand there are lots of trannies here running on dino and packing on the miles. The key thing to getting long life out of these (or almost any tranny except the svx) is regular fluid changes. SVX problem was the clutch material on the lock up torque converter would flake off and clog the cooler lines. Next thing you know is you have a cooked tranny from over heating. Nothing, synthetic or otherwise can stop that from happening. Its really up to you (but i like dino). nipper Quote Link to comment Share on other sites More sharing options...
Lawsonmh15 Posted June 15, 2006 Share Posted June 15, 2006 Automatics have wet clutches. If the fluid is to slick, it can cause the clutches to slip longer then they would normally and cause excess ware. Synthetic trannny fluid is fine for newer cras, or cars made for it. If you didnt notice a differnce in your shifting, fine. There are a number of people who noticed more shlipping in the tranny and switched back to regular fluid. Its not an automatic recomendation for syn fluid, but the hybrid seems to escape this problem compltly. It really varies from car to car. I just dont like to recomend that change on a cr that has spebt most its life with std fluid, without letting somoone realize there may be a negaitve affect on the transmission. Soobie trannies are fairly robust with the std fluid, so personally i dont see a need or the expense of the synthetics, unless you live in the mountains or tow a trailer. Tranny failures seem to be few and far between (not including torque bind). nipper May be too soon to say, but Since I flushed with Royal Purple, My notorious hard shift has dissappeared and I gained 3.5 MPG.:banana: No leaks either. Also, for a $30 price difference, it was WELL worth it. Quote Link to comment Share on other sites More sharing options...
Wayne Boncyk Posted June 15, 2006 Share Posted June 15, 2006 Ahhh -- a man after my own heart! Nice to see another endorsement of a synth ATF!! Quote Link to comment Share on other sites More sharing options...
nipper Posted June 15, 2006 Share Posted June 15, 2006 Bah Humbug .... (giggle) i will say i had the same thing on my 98 with 180K when i flushed the tranny. MPG you cant really tell untill 3 tanks of gas. I gainded what seemes like 2 mpg on my flush, but i cna vary it by 5mpg with my right foot. One nice thing about sooby trannys, they shift like new with a fluid change. nipper Quote Link to comment Share on other sites More sharing options...
Wayne Boncyk Posted June 15, 2006 Share Posted June 15, 2006 True! In all honesty, it doesn't seem to matter what fluid is in there, as long as it's fresh. That's as close as I'll come to agreeing with you, nip, on this one!! Quote Link to comment Share on other sites More sharing options...
nipper Posted June 15, 2006 Share Posted June 15, 2006 True! In all honesty, it doesn't seem to matter what fluid is in there, as long as it's fresh. That's as close as I'll come to agreeing with you, nip, on this one!! welll for older cars i still like dino (in the tranny), god knows if you put in synthetic blinker fluid the turn signals go all crazy and start leaking nipper Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted June 15, 2006 Share Posted June 15, 2006 is it ok to use the synthetic air instead of summer air in your tires??? i know you have to change the winter air, but what should i put in???? welll for older cars i still like dino (in the tranny), god knows if you put in synthetic blinker fluid the turn signals go all crazy and start leaking nipper Quote Link to comment Share on other sites More sharing options...
nipper Posted June 15, 2006 Share Posted June 15, 2006 is it ok to use the synthetic air instead of summer air in your tires??? i know you have to change the winter air, but what should i put in???? helium for better gas milage (ok now we are just getting silly):-p nipper Quote Link to comment Share on other sites More sharing options...
Wayne Boncyk Posted June 15, 2006 Share Posted June 15, 2006 Just now?? Quote Link to comment Share on other sites More sharing options...
nipper Posted June 15, 2006 Share Posted June 15, 2006 Just now?? Thats mine there's yours nipper Quote Link to comment Share on other sites More sharing options...
pitstain Posted June 16, 2006 Share Posted June 16, 2006 Nipper dont forget your teflon muffler wax.... BTW i dont think i have a spin on filter on my 98 legacy brighton built in nov 1997....also what size socket for the trans pan drain plug? Thanks Quote Link to comment Share on other sites More sharing options...
Buick350X Posted June 16, 2006 Share Posted June 16, 2006 I did the filter n fluid change to the 01 forest last week. I just wonder how many time any of ya changed it? Pan only drains out about 5 quarts. I know there is much more fluid in there. Was thinking about changing it again real soon. Water the rest down with another fresh 5 quarts. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted June 16, 2006 Share Posted June 16, 2006 it's either a 17 or a 19.. Nipper dont forget your teflon muffler wax.... BTW i dont think i have a spin on filter on my 98 legacy brighton built in nov 1997....also what size socket for the trans pan drain plug? Thanks Quote Link to comment Share on other sites More sharing options...
Lawsonmh15 Posted June 16, 2006 Share Posted June 16, 2006 helium for better gas milage (ok now we are just getting silly):-p nipper Oddly enough, I've seen shops around here offering to fill tires with nitrogen. The benefits... Quote Link to comment Share on other sites More sharing options...
nipper Posted June 16, 2006 Share Posted June 16, 2006 Oddly enough, I've seen shops around here offering to fill tires with nitrogen. The benefits... It keeps tires cooler. Unless your pullin a load, or if they are giving it away for free, anything will do. http://www.tommcmahon.net/2004/11/fill_your_tires.html nipper Quote Link to comment Share on other sites More sharing options...
Buick350X Posted June 17, 2006 Share Posted June 17, 2006 Oddly enough, I've seen shops around here offering to fill tires with nitrogen. The benefits... Your tires prressure is more unlikley to change with time. Something aobut it being smaller or larger, its harder for it to leak and lose pressure. If ya watch drag racing you will see them guys with tiny bottle of the stuff doing tires. One of them tiny bottle will air up 50 tires. Where, just plain air would barley do 4 from flat to full. Quote Link to comment Share on other sites More sharing options...
pitstain Posted June 17, 2006 Share Posted June 17, 2006 just did a drain and fill on my 98 legacy....5 qts. of catrol dexron merconIII most of my grumbling in turns is gone now.....WOW my old fluid was BOSCO....it is now strawberry quick Quote Link to comment Share on other sites More sharing options...
nipper Posted June 17, 2006 Share Posted June 17, 2006 just did a drain and fill on my 98 legacy....5 qts. of catrol dexron merconIII most of my grumbling in turns is gone now.....WOW my old fluid was BOSCO....it is now strawberry quick only 5 qts? you have another 5 to go, and yes that cures torque bind 90% of the time nipper Quote Link to comment Share on other sites More sharing options...
otis Posted June 17, 2006 Share Posted June 17, 2006 Oddly enough, I've seen shops around here offering to fill tires with nitrogen. The benefits... THere is really only ONE benefit.... for the shop- in the form of higher PROFIT. Supposed Claims: -Nitrogen is Bigger than oxygen and therefore doesn't diffuse or leak out as fast- FALSE?- I've seen diffusivity papers for various polymers which show a negligible difference- certainly not the 3-4x that some people claim (maybe 1.1x) -N2 holds pressure more constant than air- somewhat true. the problem is really the moisture in the air that gets compressed along with the air. depending on the relative humidity of the air- this could account for a negligible change in pressure. why negligible? the temp of the tire as you drive has a bigger impact on pressure than the moisture as it condenses/evaporates. -N2 keeps the tire cooler- FALSE anyone know the heat capacities of N2 vs air- negligible difference because air is about 80% N2 anyway. anyway the temp is more of a function of friction than the gas inside the tire. So why do race cars use N2? different rubber compound which is more susceptible to oxidation. when you start making turns at 100 mph, suddenly these "neglible" differences in the street tire case become "significant." so if you want to use N2 go right ahead- it doesn't do any harm. but I've seen a place here that "offers" to fill you tires for $20. All the money I save keeping the tire wear even will pay off the cost of filling up with N2 every other month- YAY! Quote Link to comment Share on other sites More sharing options...
nipper Posted June 17, 2006 Share Posted June 17, 2006 THere is really only ONE benefit.... for the shop- in the form of higher PROFIT. Supposed Claims: -Nitrogen is Bigger than oxygen and therefore doesn't diffuse or leak out as fast- FALSE?- I've seen diffusivity papers for various polymers which show a negligible difference- certainly not the 3-4x that some people claim (maybe 1.1x) -N2 holds pressure more constant than air- somewhat true. the problem is really the moisture in the air that gets compressed along with the air. depending on the relative humidity of the air- this could account for a negligible change in pressure. why negligible? the temp of the tire as you drive has a bigger impact on pressure than the moisture as it condenses/evaporates. -N2 keeps the tire cooler- FALSE anyone know the heat capacities of N2 vs air- negligible difference because air is about 80% N2 anyway. anyway the temp is more of a function of friction than the gas inside the tire. So why do race cars use N2? different rubber compound which is more susceptible to oxidation. when you start making turns at 100 mph, suddenly these "neglible" differences in the street tire case become "significant." so if you want to use N2 go right ahead- it doesn't do any harm. but I've seen a place here that "offers" to fill you tires for $20. All the money I save keeping the tire wear even will pay off the cost of filling up with N2 every other month- YAY! same with airplanes and any other heavy duty high speed use. Nitorgen is considered dry, so there is no moisture in it normally. This is the reason the military tenads to pack things in N2 so they dont rust or greakdown from oxidation. I sort of have a problem with the o2 theory. !st is that n2 is a smaller molecule then o2 and can leak out faster. Secondly the air is 78% nitorgen and 21% oxygen, so even then i cant see the leaking part. I just posted the article as a point of refernce and wanted to see what would come back. It is truly a profit thing. People have been using compressed aor with no problems all these years. Now about summer air vs winter air ....... nipper Quote Link to comment Share on other sites More sharing options...
stevecd Posted June 18, 2006 Share Posted June 18, 2006 This post has inspired me to change my atf but I ran into a weird problem, that problem is the dipstick is hard to read. Its not that the dipstick doesn't have the markings but the fluid has such a low viscosity it seems to run off before I can read it and so I can't tell how much fluid is in my tranny just wondering if anyone has any tricks or tips. Thanks, Steven Quote Link to comment Share on other sites More sharing options...
J A Blazer Posted June 18, 2006 Author Share Posted June 18, 2006 I too find it hard to read. I measured what I removed and I then replaced it with the same amount. This assumes that an appropriate amount was in to begin with, but its a start. Quote Link to comment Share on other sites More sharing options...
Setright Posted June 18, 2006 Share Posted June 18, 2006 I believe the reason for Nitrogen in airplane tyres is minimize fire risks in case of a blowout. Magnesium rims on planes. Dangerous combo if you lose the tyre and strike sparks on the runway, the nitrogen quells the tendency of the Mg to burn. Quote Link to comment Share on other sites More sharing options...
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