Synchro issues

[Sir Yach-o]

Ever since I bought this car with 110k on it, it's been reluctant to shift quickly to second, up and down. I'm guessing it's the synchros that are screwed, so here's my question.

What's the cheapest way to fix this?

1. I'm not afraid of doing this myself, with help from friends of course, but is it even concievable of taking the tranny out, apart, and replacing the synchros in my garage? I've never even seen the inside of a tranny before, but i think i would be able to figure it out. My roomate had to remove his tranny from his '86 camaro, so we've got the tools. If anyone's done this kind of thing before, let me know how hard it is. I would also need to know where to get new synchros.

2. BG synchro gearbox oil. It's been recommended to me by Al that it works wonders, but I've never seen it myself. He says that it costs about $80 to fill the tranny, and he ran ATF in there for about 100miles to clean it out first. But I'm not convinced that a simple, albeit $80, fluid change would cure my problems.

3. Bend over and take it . . . . . to a mechanic/tranny shop/dealer.

Anyone?

-mike

[DLC]

DSM guys also swear by BG, and the tranny fluid idea is also pretty commonly accepted way to clean gearboxes or engine internals.

Mine does the same, but only when it's warmed up. I'm pretty sure that it's the syncros, but might have something to do with the gear oil as well.

Dave

[Legacy777]

From what I have been told about the different revisions of trannies subaru has put out......the older trannies synchros were not the best out there.

What's happening is fluid is not able to escape as fast as it should, therefore the synchros aren't matching speed correctly....usually it's the synchro not slowing down enough.

The v. 4 trannies or something like that have an additional hole(s) to allow fluid to escape. From what I hear this does help the crunching second gear.

So you could upgrade to the latest synchros and it would probably solve your problem.

Or you can try some different fluid, as different fluids will have different properties and flow characteristics.

[93LegacyTurbo]

Mine has a resistance going to 3rd, but never a grind or crunch. Not bad for 145K mile.

[mile hi]

The BG oil is called Synchro Shift (they have several) and it has worked very well on several transmissions. The upgrade synchros appeared in the ver 3 transmissions so I have been told. These were introduced in '98-99 and some had the old bolt pattern and can only be ID'd by the number. The transmision I have is out of a '99 GT and is a ver 3. I don't think it would be a very good idea to attempt a transmission rebuild without a shop and manuals.
AL(CO)

[Sir Yach-o]

Good to see you've finally jumped aboard, AL!

I think I'll try the BG, and if that doesn't help, maybe you guys can do it for me, that is, if you and Joel do trannys.

BTW, where can I find BG Synchro Shift?

-mike

[mile hi]

I bought mine at CAR QUEST and I have heard that Advanced Auto has it or can order it. I think that it works because it contains some Zinc compounds. A friend of mine has been using it for about 60k and told me about it.
AL(CO)

[mile hi]

Things are a bit slow and I checked to see if we could fix it for you and we can. It will need whatever synchros that are bad, probably 2nd and 3rd,complete gasket and seal kit, and possible mainshaft bearing.

[entirelyturbo]

I use Valvoline 80W90 SynBlend gear oil in my tranny and rear diff and it seems to work just fine, except that you almost have to be stopped to put it back in 1st! However, I've talked to Impreza owners with the same gripe, and they recommend that upon slowing down, always go into 2nd, then 1st. It makes sense; that slows the driveshaft down and means the synchros don't take as long to match speeds.

[JasonGrahn]

i've used Mobil 1 (complete shite), Valvoline (alright), BG Synchroshift (also shite), and Neo Synthetic; all within the 80 thousand miles that i've owned my car.

A) Neo Synthetic is the best. Use that. Always.

B) Go and get your tranny fixed. My recommendation: Richard Buckner down in portland. He's a good friend of mine. Rebuilt my tranny when it finally called for it (thanks to that damn shite Mobil 1!), and has also rebuilt Will Robinsons tranny. You CANNOT go wrong with Richard. He doesn't charge an arm and a leg either, which is cool.

rbuckner@royalmoore.com
503-615-8403

Good times!

-Jason

[vrg3]

I was looking around for BG SynchroShift, and can't seem to find its GL rating, but it's usually mentioned with GL-4 oils...

Our front differentials share lubricant with our gearboxes, and so require GL-5 gear oil, right? Is it safe to use BG Synchroshift and other GL-4 oils like Redline MT-90?

[mile hi]

I have been using the BG oil for about 35,000 miles and have no problems at all. When I first heard about this I had the same question about the diff and someone pointed out to me that the BG oil was recommended by BG for cars with tranny-diff units that shared the same oil supply. An inquiry to BG might give us a little more information on this oil it sure seems to work good. Another thing we have found out recently is a lot of shift, synchro problems and some of the "chatter" problems seem to come from the clutch not completly disengaging. We had a customer put his car in gear, floor the chutch and then bring the engine speed up while we had a dial indicator on the front bumper and it moved. Also when trying to change gears while not moving you could tell that you were fighting the synchros. What I have come up with for this is a machined and heat insulated slave cylinder that moves the disengagement point up off of the floor a inch or so. This problem does seem to mostly concern hydraulic clutches on Imprezas but I think it could probably help any subie. (ALCO) al@iwtu.net