Which gear oil for 5 speed manual?

[ktdenali]

I have been researching different options on gear oil to put in my 5 speed manual transmission and rear dif.

EJ252, 2000 Subaru Legacy Outback

It is no question to use 75W90, but does anyone recommend any certain brands?

 

Synthetic or regular?

 

I have to say gear oil is kind of expensive, anywhere from $6-$15 per quart.

 

I have been looking at the Valvoline High Performance 75W90 at Carquest, which does not say it is synthetic, and the more expansive one, Valvoline SynPower 75W90 (almost twice as much).

 

Should I use synthetic (more expansive lubricant) or the cheaper kind.

I assume the cheaper kind is mineral oil, which is why it's cheaper.

 

Does anyone have any good advice here?

[GeneralDisorder]

The synthetics don't tend to work well in the Subaru 5 speed's - they have a tendancy to flow too well and cause syncro issues and grinding. A good quality non-synthetic, changed on a regular basis, is the most cost effective way to ensure reliable transmission service for the life of your car. Maintained properly, the Subaru 5 speed transaxle design can easily compete with the life of the engine.

 

The biggest mistake people make is not changing the gear oil enough. A lot of folks NEVER change the gear oil. If it's done regularly - every 30k is a good schedule - then problems don't arise as easily. An occasional flush with a full load of ATF for 100 miles or so helps to keep them cleaned up inside.

 

The plain non-turbo 5 speed's suffer most from syncro problems and input shaft bearing failure. Both of these typically related to a lack of gear oil service.

 

I would be much more concerned with head gaskets on your engine than your transmission though - the phase-II EJ25 is well known for external coolant/oil leakage.

 

GD

[ktdenali]

thanks for you helpful comments.

I will go ahead and get the regular gear oil then.

 

I know about the head gasket issue.

Unfortunately I bought his car at 126000 miles and have no idea what has been done to it as far as maintenance in the past. One big reason I am going through everything and changing all my fluids.

 

It had a worn (no cracks, tears or anything like it) timing belt on it, which was either never change or recently changed. Going off of some pictures I posted on here, one mechanic suggested that someone may have done a head gasket on it early in its life.

 

If you're interested, you can see the thread here http://www.ultimatesubaru.org/forum/showthread.php?t=108388&highlight=ktdenali

thread name is : Timing belt question (ktdenali)

and the pictures here

http://cid-5ffca51260a7352b.skydrive...7?uc=3&lc=1033

 

So I am hoping the head gaskets have been done. Since the problem is external leak, it is easy to spot, and there is absolutely not "wet" spots on the engine. My cooling fluid is consistently as the same level, at least at this point. No leaks. But I am keeping my eyes on it.

 

One thing I have not figured out yet is why my temperature gauge fluctuates a little bit going uphill on interstate. It should be rock solid.

[edrach]

I've had excellent results with Redline 75W-90NS on the older, high mileage cars that I usually drive.

 

Also, I found that the Castrol Synthetic 75W-90 which Subaru suggests is also quite good.

 

My only negative experience I've had was with the Lucas 75W-90 gearoil (non-synthetic) on my old Legacy. Within two weeks of installing it, I was getting synchro crunches shifting into 2nd, 3rd and 4th. Drained the Lucas gearoil and put in the Redline and the gearbox has been quiet ever since (almost a year ago now).

[edrach]

One thing I have not figured out yet is why my temperature gauge fluctuates a little bit going uphill on interstate. It should be rock solid.

That's usually the first sign of a faulty radiator. If the temp climbs the faster you go on the highway and/or going up hill, that's the typical symptom for the radiator being bad (or too much stuff clogging the airflow through the radiator). I've never found reverse flushing the cooling system to help and just put that money toward a new radiator.

[bobaru]

dino oil only use real out out of the earth dino oil

 

dont use that fake crap

 

you look at a truck 2,000,000 miles plus 80,000 lbs plus they use real oil not that fake crap

 

subaru puts real oil in at the factory not fake crap

 

chevron is the best or napa which is also chevron

Edited February 12, 2010 by bobaru

[johnceggleston]

dino oil only use real out out of the earth dino oil

 

dont use that fake crap

 

you look at a truck 2,000,000 miles plus 80,000 lbs plus they use real oil not that fake crap

 

subaru puts real oil in at the factory not fake crap

 

chevron is the best or napa which is also chevron

 

 

 

so, are you saying none of the fake crap?

[bobaru]

so, are you saying none of the fake crap?

 

 

You betcha I hate that fake crap. dino only

[GeneralDisorder]

dino oil only use real out out of the earth dino oil

 

dont use that fake crap

 

Synthetic is not fake - it comes from the same crude oil (yes - from the earth) that the dino does. It's just in how it's refined that it differs. Dino oil is filtered, seperated, chemicals are added, etc.

 

Sythetics are done in a couple ways - one of the most common - invented by Standard Oil (Chevron) is to vaporize the oil (vacuum boiling typically) - at which point all the contaminates don't vaporize and thus are removed. Then the oil is brough down to normal pressure again after some other processes remove the sizes of carbon chains that are not wanted for the final product.

 

But it's still oil - from the ground. And it has it's uses for sure. It's just not often justified for consumer products like automobiles IMO. The cost and the added complexity needed to use it properly (analysis, etc) is beyond what most consumers are willing to take on.

 

GD

[Setright]

Valvoline Synpower

 

 

This is the absolute BEST oil for our gearboxes. I have tried many others, from Redline to Castrol, through Mobil and Shell.

 

Synpower gives PERFECT shifts. Smooth, crunch free. A local rally driver gave the tip, and I have been spreading the word ever since. No-one has been disappointed.

 

It even cured the ker-UNCH in a 20 year old XT-Turbo. That was making terrible noises in 2nd and 3rd. Drained the old stuff out....poured in the Synpower...drove about 60 miles and the noises died down and never came back.

 

Okay, the third gear synchro must have been really worn, since a small klonk could still be felt on quick shifts up from 2nd, but I can vouch 100% for the fact this synthetic oil is compatible with a Subaru gearbox.

 

 

Please!! Do youself the honour/favour of spending the extra money on Synpower. You will be back here to thank me

[ScoobySchmitty]

 

The biggest mistake people make is not changing the gear oil enough. A lot of folks NEVER change the gear oil. If it's done regularly - every 30k is a good schedule - then problems don't arise as easily. An occasional flush with a full load of ATF for 100 miles or so helps to keep them cleaned up inside.

 

 

GD

 

ATF flush? Just got my 04 Legwag with 82k miles on it and am planning a gear oil change in the near future. I'd be all for doing this, just really worried about the kind of lubrication I would get with ATF, even for a short distance.

[GeneralDisorder]

just really worried about the kind of lubrication I would get with ATF, even for a short distance.

 

Why? ATF is used in transmissions is it not? What do you suppose is inside the Subaru automatic's? Unicorns and rainbows?

 

The only thing the ATF isn't rated for is the hypoid gears in the front diff. 100 (easy) miles won't hurt them though. Hell - people put 100's of thousands of miles through them with broke-down, sheered-off, dirty gear oil that should have been changed in a previous decade.

 

GD

Edited February 13, 2010 by GeneralDisorder

[bobaru]

Why? ATF is used in transmissions is it not? What do you suppose is inside the Subaru automatic's? Unicorns and rainbows?

 

The only thing the ATF isn't rated for is the hypoid gears in the front diff. 100 (easy) miles won't hurt them though. Hell - people put 100's of thousands of miles through them with broke-down, sheered-off, dirty gear oil that should have been changed in a previous decade.

 

GD

 

 

I personaly drove about 40 miles without a drop of oil in the rear end, IH scout. . I lost the nut that holds the pinion gear. pinion slamed in to ring broke two teeth on ring in half. rearend locked up

 

anyways found the nut about 3miles down the road.... lucky I had my tools.... pulled cover beat the pinion into place tightend the pinion nut reinstalled cover drove home...... put oil in it called it good. drove that scout for years with those teeth.

 

 

And ATF is a cleaner....... I drive motors with 50 50 ATF deisel in them cleans the crap out

Edited February 13, 2010 by bobaru

[JeffStu]

I'm a big fan of using Lucas oil additive with my gear oil. And engine oil for that matter. I run 20% Lucas Additive in the engine and 50% in the 5sp tranny and differential.

 

It's pricey but I've had good experiences in many different cars.

[GeneralDisorder]

Lucas is crap - it foams at high speed.

 

Don't put additives in your oil's. Only thing that should be in oil is OIL. If the manufacturer thought it would do any good over the long term they would have added it at the refinery.

 

GD

[ktdenali]

I am on the same page with additives.

 

I wondered the same things about what they want you to add to your coolant after they screwed up on the head gaskets. There is some sort of a Subaru Coolant conditioner out there that we are supposed to add to our fluid to fix it. Is that some sort of a bogus thing they are trying to sell us too.

 

hmmm....???

[GeneralDisorder]

I wondered the same things about what they want you to add to your coolant after they screwed up on the head gaskets. There is some sort of a Subaru Coolant conditioner out there that we are supposed to add to our fluid to fix it. Is that some sort of a bogus thing they are trying to sell us too.

 

That's a stop-leak additive to try and catch head gaskets that *could* fail in the future - it's just something that either causes swell in the seals around the coolant ports or it's got some particulates that are designed to lodge in the holes forming in the gaskets and damn them up.

 

At best it's a stop-gap solution and won't fix it forever. It's like dropping an egg into the radiator to fix a hole. Same idea but with longer term use in mind. The idea was surely to get the head gaskets to last till the warantee period expired so they wouldn't have to pop for the labor and parts to fix them for real.

 

So in that sense - yes it's a bill of goods they are trying to sell you. It will mask the problem for a while but it won't solve anything in the long run. In the case of the coolant additive though it's not going to hurt anything either but that's not the case with gear oil additives and engine oil additives. Those can definitely cause more harm than good over the long term.

 

GD

[forester2002s]

That's a stop-leak additive to try and catch head gaskets that *could* fail in the future - it's just something that either causes swell in the seals around the coolant ports or it's got some particulates that are designed to lodge in the holes forming in the gaskets and damn them up.

 

At best it's a stop-gap solution and won't fix it forever. It's like dropping an egg into the radiator to fix a hole. Same idea but with longer term use in mind. The idea was surely to get the head gaskets to last till the warantee period expired so they wouldn't have to pop for the labor and parts to fix them for real.

 

So in that sense - yes it's a bill of goods they are trying to sell you. It will mask the problem for a while but it won't solve anything in the long run. In the case of the coolant additive though it's not going to hurt anything either but that's not the case with gear oil additives and engine oil additives. Those can definitely cause more harm than good over the long term.

 

GD

Wise words. I agree.

[rverdoold]

Sorry for waking up this older thread it had been put in hibernation last winter I guess.

 

As a European i am relative unlucky in choice of product. (which are even very expensive over here).

 

But i can get the Valvoline Synpower 75w-90 full synthetic over here for a slamming 20 euros a liter (about 25 usd per quart). Is this the stuff i want to put in my gearbox and diff??

 

 

 

 

Valvoline Synpower

 

 

This is the absolute BEST oil for our gearboxes. I have tried many others, from Redline to Castrol, through Mobil and Shell.

 

Synpower gives PERFECT shifts. Smooth, crunch free. A local rally driver gave the tip, and I have been spreading the word ever since. No-one has been disappointed.

 

It even cured the ker-UNCH in a 20 year old XT-Turbo. That was making terrible noises in 2nd and 3rd. Drained the old stuff out....poured in the Synpower...drove about 60 miles and the noises died down and never came back.

 

Okay, the third gear synchro must have been really worn, since a small klonk could still be felt on quick shifts up from 2nd, but I can vouch 100% for the fact this synthetic oil is compatible with a Subaru gearbox.

 

 

Please!! Do youself the honour/favour of spending the extra money on Synpower. You will be back here to thank me