G50 syncro lifespan?

[alfisti]

I have never downshifted into first on decel. I do however downshift to second - sometimes just to hear the engine note. :-) I also feel more in control in a lower gear.


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[KTL]

Downshifting to 1st is nearly impossible if the driver is clutching it only once just like any other gear. The trans simply won't let you do it because it requires so much friction to spin up the synchros to match shaft speeds. People who are able to do it are usually forcing the trans into gear and that's a big no-no.

If you must shift into first while moving, at a rather slow speed like 10 mph, you can make it work w/out leaning on the shifter by double-clutching. Still rolling along, push in the clutch, select neutral, release clutch & bring up the revs with the throttle. Hold that rpm (don't just blip it), push in the clutch and then select 1st. If you "guessed" right with your rpm selection, the shifter should slide right into 1st. Sometimes takes a few attempts to get the rpms right.

[awhnry]

Please note that it has not been stated that you cannot downshift(in fact, a well-coordinated downshift is one of those AHHH moments in a car) but dont downshift to brake the car. The downshift should be the last movement in the corner approach rather than the first and should not upset the car's balance or motion. YMMV

[KTL]

Originally Posted by awhnry

The downshift should be the last movement in the corner approach rather than the first and should not upset the car's balance or motion. YMMV

I don't think anybody's debating that very good point. I know of quite a few people that do the downshift too soon and eventually that's going to hurt their engine more than their transmission. There's a few guys in my local circle of racers that get started on downshifting way too early, often hitting the rev limiter & likely revving it (mechanically) much higher than they realize.

[Matt Monson]

There's another turn at my local track that I eventually learned not to downshift at all as I became a better driver.

I used to slow down too much. I needed 2nd. Then I got faster, and started bouncing the rev limit on the downshift eventually reaching the point where I chirped tires with the downshift. I'm sure that was brutal on my rod bearings (should have seen the oil pan on engine teardown).

Now I take that corner in 3rd.

[Maxhouse97]

Back to the OP - have 123k and am in the process of rebuilding. Similar to KTL mine would "pause" from 1-2 (which existed since 88k), which was annoying and was worse the higher rpm I revved to in first, and start to crunch when hot.

A couple thoughts - its NOT cheap, if you want it done right. Second, I wanted to replace the stock brass synchros with steel in all gears, and it was hard to find replacement parts. I guess Porsche recently ended their relationship with Getrag, and had to source new steel synchros with other suppliers. These suppliers have not had success with quality control, etc. so we had to find old Getrag produced ones. Something to think about as material cost is just about as much as labor in the rebuild.

[Matt Monson]

My dealers have access to the old original steel synchros. I have a bunch of them, but only sell them through my shop customers.

That said they aren't an actual upgrade for a street driven car. They handle the heat and stresses of the track and racing better. But if its a street car, even one with a little DE use save yourself a few hundred bucks and stick with the old brass ones.

[chuckoslovakia]

Lost a G50 synchro at 148k. Grinded horribly into 3rd gear. Before it went out, 3rd gear would get stuck pretty often when shifting into it. All rebuilt and fresh again now. Wallet still hurts though.

[chrisbruck]

So what's the going rate for a G50 rebuild? Mine's good for a while but would be nice to start saving.

[msterling]

When I got my 88 Carrera at 37k miles. The 1-2 shift was notchy when cold, just like people are describing for cars with 100-200k more miles. I think that is how they are. Mine now has 54k miles and feels just the same. After a very short warm up time the shifts are very smooth and fairly quick without forcing anything.

[MrBonus]

I've never felt mine was notchy given its age but I guess I could describe it that way in comparison to my 2012 Wrangler or other new cars I've driven.