[RootCanal05]

My 2015 335 has 58K miles and I've noticed shifting from 1st to 2nd is getting harder and harder. No noises just seem to can't fine the gate to easily get into 2nd. I thought it was because it's getting colder out but it happens pretty much all the time now. Can this be because of the synchro? I haven't abused this car and this is my 3rd manual BMW but my first time experiencing this and I'm getting concerned. Any advice is much appreciated...thanks

[328iX]

Definitely start with fluid, the fluid contains friction additives that help the synchros slow down the gear much quicker for smoother engagement.

Also yes, a lot of transmissions will not perform well cold due to this reason, but if the issue persists when the trans is hot there is something going on.

If the fluid doesn't fix it next you'll need to look at that clutch master / slave cylinder, no visible leaks = possible air in the system preventing you from fully disengaging the clutch quick enough. Let me know.

[Wires]

I'd suggest a fluid swap as well. That and temperature will make it feel "notchy" and harder to shift.

Synchro's would show up on the downshift, not upshift. Is this happening on gentle/low rpm shifts or higher rpm shifts?

[dkreidel]

^^^ Redline MTL or BG Synchro Shift II ^^^

[Wires]

Originally Posted by dkreidel

^^^ Redline MTL or BG Synchro Shift II ^^^

Have you tried it in a BMW tranny? Only reason I'm asking is a buddy used to use it in his Mustang with amazing results, so I put it into the 6 speed manual of my 2003 Acura, and it was BRUTAL. Every shift was notchy and hard to gate. Ended up going back to OEM Honda oil to get the butter shifts. So depending on brand, your results might vary.

[rak299]

The 2 obvious things are the 2nd gear synchro ring and the clutch not completely disengaging. Synchro ring problem is bad, so assume that isn't the problem for now. The clutch is not supposed to need adjustment, but something like a little air bubble in the system can cause it not to completely disengage. (also something on the floor between the pedal and the carpet. To test, stop on a flat surface with the brake off, car in first gear and the clutch pedal all the way down. Rev the engine. If it creeps forward, it isn't disengaged.

[eluded]

What is this manual transmission the OP talks about ?

[rak299]

Originally Posted by Wires

I'd suggest a fluid swap as well. That and temperature will make it feel "notchy" and harder to shift.

Synchro's would show up on the downshift, not upshift. Is this happening on gentle/low rpm shifts or higher rpm shifts?

There is a synchro ring on each side of the 1-2 sliding, shifting gear. (also on both sides of 3-4 and on 5-6) One is used for shifts into first and one is used for shifts into second.