[2one3E90]

My car is cold and only running for 5 minutes. Ive been driving it and learning to double clutch because I love my car and want this tranny synchros to last long. Then i proceeded to grind 3rd trying to double clutch up shift twice while it was still cold. Ill be fine right? 330i with 220,000 miles

[marvinstockman]

Try changing the gearbox fluid. You can also hold second longer and go straight to fourth.

[fiveightandten]

Don’t double clutch while your transmission is cold. Just shift slowly and smoothly. I’d argue not to double clutch at all. But once everything is up to temperature you can shift as normal, and smooth shifting will yield long life.

It is *possible* for a single aggressive gear grind to ruin syncros. It’s also possible to grind repeatedly and not do any damage that alters operation. If the car is shifting ok now, you’re probably fine.

[Brian86]

It's fine.

My ZF box is at 350k and in good shape. I don't think it's necessary to double-clutch to preserve the sync rings. Just keep good fluid in there every 100k or so. I'm a Redline D4 ATF guy.

[Leucosticte]

You'll probably be fine.

[2one3E90]

Originally Posted by Brian86

It's fine.

My ZF box is at 350k and in good shape. I don't think it's necessary to double-clutch to preserve the sync rings. Just keep good fluid in there every 100k or so. I'm a Redline D4 ATF guy.

I changed the fluid 20,000 miles ago. With motul gear 300. Its shifting fine now. Okay I guess I wont double clutch anymore.

[Efthreeoh]

Originally Posted by Brian86

It's fine.

My ZF box is at 350k and in good shape. I don't think it's necessary to double-clutch to preserve the sync rings. Just keep good fluid in there every 100k or so. I'm a Redline D4 ATF guy.

I think the shifting improves with age. Now at half a gazillion miles mine shifts like butter. 100K (or longer) fluid changes w/ MTF-3

[2one3E90]

Originally Posted by Efthreeoh

I think the shifting improves with age. Now at half a gazillion miles mine shifts like butter. 100K (or longer) fluid changes w/ MTF-3

How many clutch changes did you do? and you never double clutch a upshift or downshift?

[Efthreeoh]

Originally Posted by 2one3E90

How many clutch changes did you do? and you never double clutch a upshift or downshift?

1 clutch change at 293K. Synchromesh transmissions were invented to eliminate the need to double clutch. I have no idea why with a modern synchromesh transmission anyone would double clutch in this day and age.

[2one3E90]

Originally Posted by Efthreeoh

1 clutch change at 293K. Synchromesh transmissions were invented to eliminate the need to double clutch. I have no idea why with a modern synchromesh transmission anyone would double clutch in this day and age.

How do u drive when it is cold? Like ice cold the tranny and engine?

[Efthreeoh]

Originally Posted by 2one3E90

How do u drive when it is cold? Like ice cold the tranny and engine?

Back in the day, the E30 owner's manual (and my wife's Z3 manual) state that when the engine is cold to not run past 2,000 RPM for the M20 zix and past 3,000 RPM for the M44 4-cylinder in the Z3. I've just followed that practice for the past 35 years or so on my BMWs and along with shifting slow until the trans warms up.

[PhaseP]

Double clutching is fun! High way speed, down shifting from 6th or 5th to 3rd, and getting no resistance from gear lever going into 3rd is priceless! :P And get rev matching for fee if done right.

[PhaseP]

Originally Posted by 2one3E90

How do u drive when it is cold? Like ice cold the tranny and engine?

Los Angeles and ice cold?

As Efthreeoh wrote, slow shifts when transmission is cold. Slow but steady though. Usually 1st to 2nd will be difficult in very cold weather. If it is so, you can try going to neutral from 1st , and then from neutral to 2nd. I am not talking about double clutch here, you do it while you have clutch pedal depressed all the time.

But at Los Angeles weather I doubt you would even need to do that. Just shift as you would shift without worrying about it. If you are not noticing difficulty in getting into gear, you don't need to do anything special.

[jsunma]

Originally Posted by Efthreeoh

Synchromesh transmissions were invented to eliminate the need to double clutch. I have no idea why with a modern synchromesh transmission anyone would double clutch in this day and age.

This.