My ailing tranny...

[555BCTurbo]

Ok...maybe one or more of you could provide me with some advice...

I have a 1992 SS 5mt, and my transmission works pretty well, except for 2nd/3rd gear syncros are a bit worn...but the biggest problem is that when I let off the gas, and the car starts coasting, the differential starts making a grinding noise, but only when coasting...

Also, when in neutral, the transmission makes a decent amount of noise, as when I push the clutch in, the noise lessens significantly. Just kind of a "parts moving" kind of noise, nothing tooooo bad sounding...

Anyway, I figure I may need to rebuild my box before everything goes pearshaped on me...

So my next question...

Can we get rebuild kits for these trannies?? I would need seals, syncros and bearings methinks...Gears seem to be fine...

Oh...and I am really poor (i.e. in college)

[Fishy]

I have a 1992 SS 5mt, and my transmission works pretty well, except for 2nd/3rd gear syncros are a bit worn...

>The guys over at honda-tech.com claim GM synchromesh fluid (friction modified) is THE smack for making worn synchos get along.


but the biggest problem is that when I let off the gas, and the car starts coasting, the differential starts making a grinding noise, but only when coasting...

> knowing very little about the guts of subaru manual trannys this doesn't sound particularly good to me

Also, when in neutral, the transmission makes a decent amount of noise, as when I push the clutch in, the noise lessens significantly. Just kind of a "parts moving" kind of noise, nothing tooooo bad sounding...

>My civic also does this. My theory is that with 224,000kms on it it still has the original clutch and related bearings. Those bearings are finally beat up enough to complain audibly. I'm pretty sure that a clutch kit comes with at least one of those bearings.

Can we get rebuild kits for these trannies?? I would need seals, syncros and bearings methinks...Gears seem to be fine...

Oh...and I am really poor (i.e. in college)

My other comments start with the ">" in the quoted part there.
I can't help much with the last two but if you wanted to try synchromesh it shouldn't cost much

[555BCTurbo]

yeah, I changed my gearlube last friday, and tossed a quart of MT90 (redline version of GM stuff) in it with the rest being GL4...


It isn't really shifting any better, but I thought it was worth a try and it was due for a change anyway...

[AWD_addict]

I haven't been able to find any total rebuild kits yet. Closest I've come is the 5mt gasket and seal kit (32001AA160).

I'd also like to know about kits with syncros and bearings.

[BAC5.2]

Ooo Ooo I might be able to help!

The parts moving noise, my tranny does it to. To SOME extent, that's normal. While idling, clutch out, 1st and 2nd gear are spinning at idle speed. So when there is movement, there is commonly noise.

If the noise has gotten worse lately, that could be bad and you could be shearing little bits of synchro off into the fluid.

The coasting and grinding thing, again kind of normal. It's very difficult to blow a front diff. This noise could also be the synchro flakes in the tranny just kinda bouncing around everywhere.

What you need to watch out for, is that bit of synchro that will nick a tooth or get caught in the wrong place at the wrong time.

As long as you didn't actually BREAK a synchro, using very good fluid will help tremendously. Use Redline Lightweight Shockproof fluid.

If there is one thing our shop is about, it's drivetrains. Our website is even called GearboxTech.com. Lightweight Shockproof is the best transmission fluid you can use. There hasn't been a car we've put it in, that doesn't drive like new.

Also, about the rebuild kit. No such thing really. You could buy every part number in the Subaru catalog and assemble it, but that's about it. They no longer make the gears or any other parts for our transmissions. I know, I've checked. At least the dealer I called had no parts in stock and had no ability to order them.

A rebuild would be difficult, and not something you could do yourself. You could probably "figure it out" but it would take you a while and it'd probably blow up soon after installation. Factory lash spec is in thousandths of an inch. To replace synchros, you need to totally disassemble the gearset, then reassemble it again.

If you want to use a new tranny, get one from a WRX and swap your center diff and gears over to it. Or use a WRX transmission and rear diff. Or just try to find another SS transmission.

Good luck! Cheapest way will likely be to find another SS transmission.

Oh, and some dog engagement gearsets will drop into our cases with almost no modification... but that's really not an option I think you'd consider... plus, it would cost you a lot more ($6000 range). Newer Synchro gearsets will NOT work in our transmissions.

[Tleg93]

Good post, Phil. I've been wondering about obsolesence with the transmission. For me, I'm wanting to get a 5mt. Now, I'm not so sure it's the best bet. What's the deal with the 4eat? I'm betting that they still sell rebuild kits for those. I have a couple of other questions too. Is this because there's never been much of a need to rebuild our transmissions? Or is it because the 5mt is specific to our cars. What about using parts from an NA tranny?

[Subtle]

On the 4eat, you might check out IPT Performance or Level Ten

[BAC5.2]

The reason for no rebuild kit, is because there have been so many revisions for synchro design and such.

Also, there really isn't any such thing as a rebuild kit. Even my shop has to order part-by-part.

Also, through it's given life a manual transmission shouldn't need to be rebuilt. The gears shouldn't need to be replaced, and the synchro's shouldn't either.

While newer synchros are smoother, they aren't as durable as the older ones were. So while our transmission has a very archaic synchro design, it's fairly durable.

Using Lightweight Shockproof will help your transmission shift perfectly again.

MT90 is a GL-4 fluid, and isn't recomended for our cars. Vikash is using it, and his car shifts very well, but LWSP is even better.

Our transmissions are very very very similar to JDM V4, 5, and 6, transmissions. All had the shot peened gears from the factory with various ratios. In fact, I'd almost be sure that the transmissions in our cars are nearly identical with those from at least one JDM STi.

No one makes an upgraded synchro for any Subaru application that I've seen. Though OEM is pretty nice, and 05 gets a double cone synchro on 1st gear now, which is cool.

Unfortunately, the reverse synchro hasn't gotten much attention and still sucks.

[93forestpearl]

Hmm. I thought there was no reverse syncro.

I've looked around at 5mt parts and the best I could find was $255 for the syncro set and $255 for the bearings. My 1-2 is shit and I need a rebuild, but since I might get the STi-RA gearset, I'm holding off. At the moment, I don't know if I can use my NA case, or if I'll have to get a blown WRX tranny.

[555BCTurbo]

Phil, thanks for the good info!!!

I have now found another option, as Barrett at All Wheels Driven said he would sell me a SS tranny that just needs 1st gear, and he said that the gears are obtainable, as he has redone a number of them.

My differential is pretty damn loud under compression breaking, but the noise hasn't changed in the 8000 miles I have been driving the car, so I think you must be right about it not being that tragic...


Anyway, I appreciate your help, because you have been able to give me some definate answers that I have been needing for quite a while !

[AWD_addict]

I've looked around at 5mt parts and the best I could find was $255 for the syncro set and $255 for the bearings.

The synchros are about $30 per shaft at a dealership.
main shaft synchros 32614AA052
pinion shaft synchros 32604AA070

These are for a turbo trans. Or I could be mistaken, since your price is way beyond what I found.

[fishbone79]

It doesn’t sound like your synchros to me. I’ve heard this case on a couple of MTs, one of mine even… The bearing on the mainshaft, directly in front of 5th gear was culprit on all of them. Does it grind audibly when idling in the driveway cold, but stop when you put the clutch in? Does it make a hellava racket on a cold-coast? Does the noise go away somewhat when nice and toasty warm? That’s what mine did; when I replaced the tranny (after losing 4th), I had to know what the noise was. It was that bearing, it’s been a couple of years since I’ve looked at it, but I think it’s in front of 5th on the mainshaft. I had also noticed some difficulty shifting for a while before 4th went, and some snarfy synchros. Just a thought though, hope you get to the bottom of it.

[BAC5.2]

Phil, thanks for the good info!!!

I have now found another option, as Barrett at All Wheels Driven said he would sell me a SS tranny that just needs 1st gear, and he said that the gears are obtainable, as he has redone a number of them.

My differential is pretty damn loud under compression breaking, but the noise hasn't changed in the 8000 miles I have been driving the car, so I think you must be right about it not being that tragic...


Anyway, I appreciate your help, because you have been able to give me some definate answers that I have been needing for quite a while !

You may get screwed if you buy that tranny.

Needing a new 1st gear, means replacing the input shaft and the mating 1st gear on the output shaft. If ANYONE tells you that you don't need to replace the input shaft to replace first gear, they are wrong.

It'll be cheaper to buy a WRX tranny that's used than to do that.

Reverse is synchronized. It's next to 5th gear. When you shift into reverse, you are pulling back on the 5th gear selector.

[vrg3]

But it's as if reverse gear's synchronizer turned backwards, right? So it only works if you're stationary anyway. Right?

[High PSI]

Using Lightweight Shockproof will help your transmission shift perfectly again.

MT90 is a GL-4 fluid, and isn't recomended for our cars. Vikash is using it, and his car shifts very well, but LWSP is even better.

Here's Redline's description of their LWSP oil:

A unique gear oil designed to lubricate racing transmissions and transaxles which see serious loads (not recommended for most syncro-type transmissions). It has excellent low-temperature flow which allows easier shifting when cold. May be used to obtain maximum power transfer in racing differentials which do not see high temperatures. Similar to a 75W140 gear oil, but with the lower internal friction of an SAE 30 motor oil.

Redline recommends against using this with most synco trannies, so I'd be a little skeptical. It's description, which puts an emphasis on racing, makes it sound like it'll make your synchros initially grip like crazy, but that this added friction will end up wearing them out VERY quickly - a concern you don't have when you only drive a car on Sundays.


You mention that Redline LWSP will make your car shift perfectly again - but for how long?


You also mention that over a trannies life it shouldn't need to be rebuilt. What, then, do you consider the "life" of a tranny to be? As long as the car lasts? Isn't the point when the tranny starts to work improperly (i.e., synchro's are worn, shift rail is shattered, gear is stripped of a tooth or two) the point when it's considered to have "died"?

[vrg3]

Phil, do you have access to any information about the chemical makeup of any Redline Shockproof oils?

[BAC5.2]

We've used LWSP in cars for 20,000 miles and not had any problems. PPG even recomends using it.

It does really depend. If you are all about performance and racing, LWSP and change it every 10 to 20k. If you want daily drivability and don't want to change the fluid all of the time, use some cocktail 50% Mobil 1 and 50% LWSP. A lot of people have used that setup, and seem to really like it for lots of miles. If you want lots of performance from a synchromesh transmission, you should change your tranny fluid every 10 to 20 thousand miles.

High PSI - Yea, your definition of a "dead" transmission is about right. But under manufacturer spec (fluids changed, stock power, etc), a transmission won't "die" if driven correctly. Of course, you CAN destroy or break synchros and stuff, but usually your doing something the tranny wasn't really designed for.

I see 300,000 mile Toyotas with manual transmissions that are still running around.

Transmission failure is very common with "performance" cars though, as people THINK they can drive, but in reality they can't. Read some of Uncle Scotty's posts on Nasioc, and listen to him chastise people who blow up trannies.

[High PSI]

BAC5.2...just curious as to when and how exactly you became an expert regarding our trannies? In my tranny-fluid research I stumbled across this thread:

http://bbs.legacycentral.org/viewtopic. ... ange+fluid

Just a year ago you were asking how to change your fluid and what fluid to use, and now you're giving advice as if you've had years and years of experience with these trannies?

I'm not trying to be a dick, I'm just a little confused.

[vrg3]

A lot has happened in a year... Visit the web site referred to in his "location."

[BAC5.2]

A lot changes in a year. I am by no means an expert, nor do I claim to be. But I DO understand manual transmissions (specifically Subaru), and I DO have personal experience with LWSP. I learn a lot of stuff every day, and due to the nature of the place I work, a lot of what I learn is about transmissions.

If you were interested, I could break down every movement of a Subaru transmission. From what happens when you push the clutch, to what happens when you shift into reverse, to what happens when you actually break something in a transmission.

Read Redline's description again. Not recomended for MOST
synchronized transmissions. MOST, doesn't mean all. It's recomended for "problem gearboxes". The reason it's not recomended for MOST synchronized transmissions, is due to the incredibly LOW coefficient of friction. The coefficient of friction is significantly lower than 75W90. But the kicker, is the film thickness of shockproof is similar to a 250 weight gear oil (for heavyweight, 140 for lightweight), but with the friction of a 75W90NS (a fluid like 75W90, but that doesn't have any friction modifiers in it).

It's like a thicker gear oil, with the friction of a lighter gear oil. COBB even recomends the Superlight variation of Shockproof. Granted most of my experience comes from a "higher performance" outlook, as I deal mostly with cars and drivers that push their vehicles further than your average daily driver. We use LWSP in lots of highly abusive situations, where it's common to squeeze every ounce of available power out of an engine and drivetrain.

Do some searching, and I doubt you'll find a poor comment about Redline's Shockproof gear-oils in Subaru Transmissions.

In my opinion, fluid change intervals should be 10 to 20 thousand miles depending on how much you abuse the drivetrain.

You may not have intended to come off as a dick, but you did. So if I may be as blunt as yourself, when did YOU become an expert regarding Subaru Transmissions?

[Subtle]

[555BCTurbo]

Dudes...chill out!!

Phil, as far as using a WRX tranny, I don't really want to because they are spendy and my good buddy Todd (-K-), whom has a WRX, said the ratios totally suck ass, especially compared to the SS tranny. I think I could definately rebuild my transmission for way cheaper. As far as building one with a bad 1st, Barrett said that I could press a new 1st gear onto the mainshaft, and I do believe him as he has had a ton of these things apart, and broken a lot of 1st gears (that dude rallies hard!! )

[High PSI]

Hah, way to edit your post up about 4hrs after you posted it.

To answer your question, I'm not an expert regarding Subaru trannies, and you know what? I don't have to be. I don't have to have ANY credibility or know a damn thing about them because I'm not giving any advice, I just looking for answers. As such, I don't see ANY problem with raising a red flag over finding that "Phil the Tranny Mechanic" giving the advice about rebuilding transmissions and how to add longevity to the life of one, was asking how to change his fluid about a year ago (at which time he obviously knew NOTHING). Is it so offensive for me to ask about your experience before I trust your word on something that could potentially destroy the drivetrain of my car? I think not...but that's just me - maybe I've struck a nerve with you due to a bit of insecurity.

Regardless, your last post doesn't give me any more confidence. It sounds like you have pulled all of your "knowledge" regarding Redline fluids right off of the Redline website. And I believe (please correct me if I'm wrong), that some of your information is even flat out incorrect.

You state:

The coefficient of friction is significantly lower than 75W90. But the kicker, is the film thickness of shockproof is similar to a 250 weight gear oil (for heavyweight, 140 for lightweight), but with the friction of a 75W90NS (a fluid like 75W90, but that doesn't have any friction modifiers in it).

So, if I understand you correctly, you're saying that the friction of LWSP is LOWER than 75W90. And that the friction of LWSP is SIMILAR to a 75W90NS (so 75W90NS has a lower coefficient of friction than regular 75W90). And that the reason that 75W90NS has lower friction is because it DOESN'T have friction modifier in it. So this implies that friction modifier INCREASES your coefficient of friction.

If this is what you're saying, this is flat out incorrect. 75W90NS has a much HIGHER coefficient of friction than regular 75W90. You're right that the difference between the two is that the regular 75W90 has the friction modifier in it, but friction modifier LOWERS the friction of the fluid, not raises it.

And still I have the question myself - HOW does LWSP help a hurting synchro? You've explained all the physical properties of the fluid, but haven't explained how it actually helps the synchro do its job. From my experience, if you're synchros aren't doing their job properly due to wear, you can get a little extra life out of them by going with an oil with more friction, not less.

We're all after the same thing here - information... just so long as its correct.

[Legacy777]

From my experience, if you're synchros aren't doing their job properly due to wear, you can get a little extra life out of them by going with an oil with more friction, not less.

I'd agree with you here, assuming the wear is normal wear, and not something odd is damaged.

The only thing I can say for sure about subaru transmissions and gear oils is that there is not one holy grail. I've run several different fluids, and had different results then people that have run the same fluids. Read other boards, even this one, and you will find the same thing.

[BAC5.2]

High PSI - Who edited their post 4 hours later? Surely you don't think I did...

In response to your accusation, I was backwards. I apologize for that, sorry I'm not perfect every minute. I was in the library writing an english assignment while replying to your message.

First, let me say one thing. First gear is machined onto the input shaft, not pressed on. Unless the SS transmission is massively different than any other Subaru tranny I've ever ripped into, you can't press a gear onto the input shaft. You CAN press first gear onto the output shaft, but if you break the output side of first, then you most definately broke the input side of first. I've got pictures to show this to you.

About the LWSP. As far as how or why it helps hurting synchros, I can only give you a best guess and personal experience. EVERY Subaru I've EVER been in that is grinding while going into gear has had this problem solved by adding LWSP.

My specific "guess" as to why LWSP works and helps, is the thickness of the fluid is greater than stock, with similar friction properties to stock fluid. So that is where I would "officially" stand. It helps because it's similar to stock in terms of friction, but thicker than stock fluid (significantly so). Is that the real answer? I'm not sure. I know that we use it at the shop, and it goes in some of the highest output Subaru's in the country, and one of the best gear makers in the world recomends this fluid for their gearsets (which use stock synchros). I've also driven at LEAST 50 Subaru's using this transmission fluid and not a single one of them had any problem with shifting or durability.

So there. Call me stupid. Tell me that a year ago, I knew "nothing" (which isn't true, this was simply the first manual transmission vehicle I've owned and done this type of maintainence on), or whatever other ridiculous conclusions you feel like jumping to. I know that LWSP has been GREAT in every subaru our shop has ever put it in. Believe me or not, I don't care. Use whatever you feel will work best for you. It's your transmission, not mine. As for me, I'll be using LWSP in this tranny, and my next one, and every Subaru I own from here on out until I find a fluid that is better.