Yummybud924

When I bought my car 2 years ago it had no grinding gear issues and that was in the summertime. Then it started grinding a bit only during the first 10 minutes of driving. Now in the winter it's grinding going into 2nd gear all the time.

I tried swepco and it got rid of the grinding problem during the summer so it wouldn't grind right from start up. Then now past few weeks it's grinding almost evertime I shift from 1st to 2nd but sometimes it won't grind, kind of strange.

I just changed it redline mt-90 and it still grinded twice.

so now I want to know if I'm shifting properly. I usually rev to 18000-3500 rpm and then shift into second. I step on the clutch wait like a second then shift.

but then I noticed today that if I rev it a bit higher and shfit quickly it didn't grind.

what would be the best rpm / speed to shift into 2nd to avoid the grinding and is it better to depress the clutch and wait a second or 2 and then shift or shift quickly while the rpms are up?

also what is rev matching?

the grinding into second gear all the time makes me nervous.

Catfood

ok Ill give you a brief cover of what you should do. Upshifting grinding really isnt that big of a deal. My dad's 928 has been doing it for years, its just your syncros worn out. I personally wouldnt worry about it. If it bothers you then a new tranny is probably in order. You have gear oil correct?

Rev matching is when you downshift by reving your car and matching the gear down. For instance when you downshift your car the revs jump up correct. This is made possible by your cars syncros getting the car into the gear. If you rev the car to where the revs would be when you downshift by first placing your foot on the clutch, then reving the car to the desired rpm and then changing gears and releasing the clutch. In this way your not using the syncros to change the gears you are meeting the gear with the correct engine speed. Next time your driving around give it a whirl it really isnt hard, you'll have all the gears memorized by ear in no time.

Yummybud924

lol I rarely even downshift. I just put it in neutral and coast and brake to a stop.

I'm worried about the grinding when I shift from 1st to second. I just changed it to redline mt-90 from swepco 201 and it still grinds. in the summer it wasn't even grinding, not sure if it's due to the cooler temps now but it seems to be grinding more often now.

but sometimes it grinds and sometimes it doesn't so I was wondering if it has to do with the rpms/ my speed when I shft from 1st to second.

like what is the best rpm / speed to shift to second to reduce the grinding.

Yummybud924

so you think the transmission can grand for years and not break? the grinding noise makes me nervous. grinding can't be too good for the metal gears.

when I drained the transmission fluid I did not find any chunks of metal though so that's good I guess....

roman944

you should really learn how to downshift and save some of your brake life, just try to take it easy in hard rain/snow, 'cause if you do it hard your car might fishtail and spin out

as far as your RPM's - that's pretty much where I shift, no problems with grind though, maybe your linkage needs adjusting? have you done anything where you had to touch it? are you short shifted?

if it does it at random then it is most likely syncro's, unfortunatly there isn't much you can do about it, and the guy above said that it shouldn't be a problem - well, I don't know about these Porsche's, but on my A6 I lost gears when the syncro's went - not trying to scare you, as I don't know how important/functional they are in these cars, but watch out

Zero10

Umm downshifting to save brake life?

Hold on a second, what's cheaper, clutches and synchro's or brakes? Don't listen to this advice, seriously.
I will only ever downshift for the purpose of braking if I am in a situation where I MUST maintain all of the available traction on my front wheels but still must slow down. a.k.a. very rarely.

Since you asked a procedural question about upshifting let's answer it
You should rev to 2800rpm+, push the clutch in, and as soon as you feel the clutch disengage move the shifter out of first then put gentle downward pressure on the shifter towards second and it should grab at just the right time to be letting the clutch out as the engine falls to the right RPM's for second gear. Sometimes you will find yourself touching the gas to keep the revs from falling too far (i.e. when the engine is cold it winds down real quick). I shift from first to second with 2 fingers on the front of the shifter, however I have to keep my foot lightly on the gas pedal when shifting or the revs fall off to quickly.

Downshifting is another game, I'm a 'heel-toe' man, I identify the term since I am not literally using my heel and toe but rather using the opposite sides of my feet since I have very long wide feet. Heel-toe downshifting is great for entering corners on the track but it has very little useful purpose in real life driving, for the most part you are braking for traffic lights not corners, so you're coming to a full stop and downshifting is both extra work and wear on your transmission/clutch.

Yummybud924

well the engine revs falling won't have anything to do with the gear grinding.

I was just wondering what speed to shift to second. so I guess I should rev to at least 3k rmp in first and then shift to second.

that's what I usually do but it has been grinding all the time lately, maybe the colder weather or just the 2nd gear synchro is going real fast.

I usually push the clutch it wait a little and then slowly **** to second but it still grinds a lot of times. Other times I **** quikcly and it doesn't grind.

so I'm wondering if I'm doing something wrong causing it to grind sometimes. Obviosly second gear synchro is not in good shape but how I'm driving probably contributes to it grinding more often.

Yummybud924

yeah I'd rather change brake pads and rotors than wear out the clutch and transmission faster. that's why I don't downshift much. I just pop it in neutral and use the brakes to slow down.

roman944

it will be pretty hard to come to a complete stop by downshifting
what I meant was like if you are cruising in a 5th gear on the highway say @ a going traffic rate 70mph and everyone is slowing down to like 40 then instead of using brakes just let your accelerator go and downshift into 4th

basically use common sense

if you see an exit that you need to take, you know you are going to have to slow down, you still have to watch your RPM's and @ what speed you are going @ so you can downshift instead of braking

I didn't offer it as an alternative to braking, and from anyone I ever talked to that drives manual, downshifting makes perfect sense

me97ggl

I have the same grinding efect. There is a diference though. Mine grinds only when i am changing gear at red line. Once i am on full throtle and try to change from first to second gear, if i make a quich shift, i get this grinding noise, and then i have to push the clutch again (meanwhile the rev fall down) and then try again.

Now i avoid quick gear changes from 1st to 2nd gear.

Sometimes the sound feels like the cluch is not pressed all the way, but believe me once i heared that noise once i then keep pressing the pedal all the way.

Any guess of what might be wrong?

alordofchaos

^ ^ ^ What Zero10 said. Take the following with a grain of salt because I'm no expert, but this works for me.

Not so much about what RPM you are in first (as long as you aren't bogging it in 2nd gear), as it is matching your revs to what it will be in your new gear based on yourRPM when you shift.

I haven't driven my 944 in quite a few months and I'd gotten used to shifting kind of by ear, but what you want to do is note how many rpms difference you have between gears at a given speed.

Let's say that at 15 mph in 1st gear, you're at 3,000 RPM. In 2nd gear going 15 mph, you're at 2,500 RPM. You have a 500 RPM difference between 1st and 2nd. If you shfit 1-2 at 3,000 RPM, you want to make sure your RPM is around 2,500 so your car is not relying on the synchros to mesh it up. It's smoother and easier on the clutch.

So, let's say you're trying to move quickly. You bring the car up to 4,500 RPM in 1st gear. What you want to do is, when you shift to 2nd, blip the throttle so that it's around 4,000 when you go to 2nd.
If you're revving to 18,000 RPM, you're either doing something seriously wrong, or seriously right!

BTW, get the right Redline MT90? It fixed my occassional 2nd gear grind. Redline MT-90 75W90 for LSD and 75W90NS for non-LSD

V2Rocket

944CS

try just pulling back on the lever with just enough force to slide the gearshift lever into second - this will take longer and your rev's will drop back down to idle, but for worn synchros, the slower the shifting, the better. What you are doing is allowing the gears to mesh when they are 'ready', i.e when they are aligned properly

yellowline

Best advice here.

Just say Mississippi under your breath while holding the stick against the 2nd gate. Then shift into 2nd; it shouldn't grind.

If you need a jackrabbit start, you bought the wrong car.

Yummybud924

Yes, I have the special formual 1 edition 944 that revs to 18,000 rpm


Thanks for the advice, I'll try the slower shifting but I already shift pretty damn slow into 2nd.

I don't think it's the clutch as all other gears shift very smoothly, no problem going into 3rd ,4th and 5th, never grinded those gears.