Thought i read going through the gears <engine off> many times may help <30>mins to remove burs from syncro <its free>

 

Oh man, before you think about touching even the gearbox fluid, bleed the clutch hydraulics ASAP. That realistically is something that should be done every 3 years or so since it’s essentially the same as your brakes but with way less volume of fluid and is used way more often. Sounds like your clutch is not fully disengaging from the weak hydraulics and you are partially power shifting. If that solves it, you’d want to change your fluid to get the metal out of the system.

There is a thread with a procedure from Billman250 for knocking off burrs to smooth out the synchros as the previous reply mentioned. I learned the hard way to never skip gears without at least rowing through the previous gears. I did 1-2-3-6 a lot and locked myself out of 5th and 6th for a bit.

 

Why did the transmission need secondary shaft bearings replaced? And did the notchy shifting start after this fix?

Thanks!

 

In late 2023 the car started to get some noise from the transmission at speed - we put it up on a ramp and could hear noise from the rear end of the gearbox, had read around that secondary shaft bearing failure was not uncommon so had those replaced

The noise is now gone and the issue with the gear shift was not apparent straight away.

As mentioned in the first post, ever since we have had the car (10 years or so now) it has always had a feeling of a blocked 4th gear when stone cold, but once selected OK.

The issue with the other gears presented itself maybe 4 months after the secondary shaft bearings were replaced.

Suspicious I agree, although as far as I am aware (I didn't do the job), to access the secondary shaft bearings you don't have to mess with any synchros or selectors?

 

Maybe damage to the shift linkage?

 

OK, so yesterday I took the car out of storage and decided to try running through the gears, with the engine off, repeatedly - as suggested.

The notchiness did improve after about 10-15 mins of shifting, but it still wasn't 'silky'.

So I decided to take the car for a good run, get it nice and warm, trying to rev it out in each gear as best I could - after a good 20 minute drive I'm happy to say the gearshift felt just like it did prior to the car being laid up.

I suspect lack of use has not helped. So plan to give it a few more runs over the next week or so then drop the gearbox oil again. Previously I used Honda MTF, and the garage who last worked on it used something different.
Is it worth trying Royal Purple Synchromax - likely to improve the shift over the Honda MTF??

 

I use and like Synchromax in my S2000. But some swear by Honda MTF. I don't think you can go wrong with either.

Nice to hear the fix was cheap and straightforward.

 

Change the gearbox oil and the box will feel smoother regardless of what you put in there. Looking at the spare bottles in my garage I must be using Royal Purple SyncroMax but I know I used Honda MTF earlier.

-- Chuck

 

I am currently running Redline fluid in my transmission and it has been very good.

 

I switched the old fluid to Royal Purple then back to Honda MTF. Feels pretty dang good now.