Thought Synchro Was Gone--Now It's Back

I thought I'd lost 4th gear (of all gears). The synchro seemed shot, and I had to rev match to get it in to 4th (up and down). Then I burned up my ACT Street clutch. So, I put in an ACT 6 puck, sprung-hub, and thought I'd drive it till the tranny gave up for good. After the clutch install, 4th gear seems to have fixed itself. I know that can't be true, and that perhaps the first ACT was not totally disengaging or something. But 4th was still a problem as that clutch wore to nothing. Anyway, I expect the problem will reappear, but it's been almost 8,000 miles on the new clutch, and I have zero problems. I did change the tranny fluid when I put in the clutch, but the car only had 28K on it, so I doubt the fluid was so messed up that it effected the synchros. But maybe?

 

Any thoughts?

Fluid can be the cause of major heartache, for sure.

 

There are all kinds of possibilities, but the one that piques my interest first and foremost is: Why did your ACT street clutch burn up so quickly? How many miles did you have on it?

 

A 6-puck is far too much clutch for all but the most aggressive Subaru's.

Well, it simply slipped from the get go. It was slipping in 1, 2, and 3 on the dyno during the tuning session. It may have been an anomoly, as it lasted only 3,500 miles. My buddy has a bug eye putting down +400 numbers and he's running an ACT Street with no problems. But, my car also weighs a heck of a lot more. I didn't just want to install the same disc that had just failed, so I went one step up, and I'm happy. It's very driveable after just a bit of practice. I lose focus once in a while and it shudders. But it does not slip. And, I'm putting down 365 wtq, which isn't a huge number, but sure isn't small either.

 

I leaning to gear lube, as it's the only change I made that could have influenced the synchos. I didn't use anything fancy, just plain old Quaker State.

Has to be an anomaly, or improper break-in or installation error. Occasionally, there are manufacturer defects with ACT, but it's few and far between.

 

The OBXT doesn't weigh THAT much more than a WRX, and it doesn't weigh more than LGT's running that same clutch with lots of power. That doesn't really matter much, though. As long as you are happy with the new clutch, that's what matters most. Just realize that it's quite a trans-breaker if not used judiciously.

 

Fluid makes a big difference. It's worth running good trans fluid.

I had a grind going into 4th gear (upshifting and down) and thought it was the synchro. I followed BAC5.2s advice and changed out the fluid and my tranny shifts like butter now. I was very surprised at how much just changing the fluid would change the feel of shifting, let alone completely remove any grinding.

Your ACT clutch was either defective or installed improperly.

 

I vote improper install and that was causing your 4th gear issues.