5th gear prob

[amo]

need some advice had some prob with throwing it in 5th at high revs
if revs are high it crunches as i put it in
drop the revs and not a prob

all help welcome

was thinkin may be some syncromesh oil or some thing

thx amo

[AR]

Amo does this happen when cold? Also is this with the BBSC?

Cheers,

AR

[amo]

Amo does this happen when cold? Also is this with the BBSC?

Cheers,

AR

hi mate no all the time
bbsc not installed yet

and only in 5th


thx amo

[simonprelude]

Sounds like the synchro for 5th gear is on it's way out :(
Gearbox apart job.

[Steveycaz]

I get this as well. Not all the time but commonly when I am 'giving it some' http://209.85.48.11/9324/101/emo/3gears-rhd.gif

[amo]

any idea wot part i need pls

thx amo

[simonprelude]

This might help to diagnose :(

If you need a copy of the Service Manual let me know.

[simonprelude]

Or it could be an issue on the Shift Fork Assembly.

[amo]

thx simon and every1 for your help

will pass this on to my garage

thx amo

[rkanaga]

Yup sounds like the synchro. Mine had this problem, and as my car was having a clutch done, I decided to get the gearbox shipped off to a specialist to be rebuilt (and have the preventative snap ring upgrade - it hadn't gone but the car was in range so getting it done was a no brainer especially at US prices for the replacement casing.)

I believe that the problem was some roughening on the synchro, but I have emailed the guys directly to get the full low down and will let you know what they found.

In any case it sounds like a gearbox out job to fix, so it depends on how much it bothers you and whether you are having a clutch done soonish anyway.

How many miles have you guys done by the way (mine had 30k on it)

regards


Robin

[amo]

hi robin

car has a uprated clutch so thats good
55k milage
ya that would be great help the more info the better

thx amo

[AR]

Amo do not forget that your box is modified, so let them know as well just in case they have to change something and go back to standard.

Cheers,

AR

[m666 edd]

I thought I'd add to this rather than making a new thread.

I have the 5th gear synchro issue like Amo had.

I can shift into 5th fine when not driving at high revs, if I rev match / "double clutch" between the shift or just shift slowly. So I guess I'm basically saying it shifts fine if I ensure the synchro doesn't have to do much work.

I have a couple of times purely out of bad habit shifted from 3rd to 5th at high revs and the synchro certainly doesn't like that!

As I don't know the technicalities of gearboxes very well, can someone tell how much work / what is involved to fix this? I've looked at the images supplied by Simon but it doesn't really give me an idea of the scale of the work that is required.

Cheers

Ed

[AR]

Sorry Ed the impression that your car had the 6 speed box?

[m666 edd]

Sorry Ed the impression that your car had the 6 speed box?

Not quite sure what you mean here but it's a 5 speed box :)

[NSXGB]

Going to be a bit of work. Do you have the JDM gearing? If not would be a good opportunity to get them in there.

Kaz would be a good port of call if you don't want to strip the box down yourself. There is at least one special tool required I believe to complete the job which I'm sure he'll have. He's also got experience with the OS Giken diff.

Would imagine it would be advisable to replace every synchro whatever and inspect\replace gears as necessary.

I hope you have a few pennies in your money box as while you're there it's obviously worth doing the clutch and driveshaft refurb too.

[amo]

hi mate sorry not updated this changed the gearbox as i blown the os genken diff on the the 1 with the 5th gear prob but have another gearbox in now

sorry mate not much help
thx amo

[goldnsx]

...can someone tell how much work / what is involved to fix this?

It takes much more work and bucks to fix it than you saved in the past with jumping the gears. ;) If the tranny is out and the mechanic did it before, maybe five hours.

Don't skip gears! The best way to kill the 5th gear synchro is to rev the hell out of the engine in 2nd gear and go directly to 5th. The 5th gear synchro can only wear out from upshifting.

[markc]

I can shift into 5th fine when not driving at high revs, if I rev match / "double clutch" between the shift or just shift slowly. So I guess I'm basically saying it shifts fine if I ensure the synchro doesn't have to do much work.

Strange that it's 5th that's exhibiting the fault. Due to the speed you'll be going at if changing up at high revs, >100mph, it's the least likely gearchange to experience the large rev drop or be rushed by the driver. Certainly on track, where as you know your car has spent some time, it would hardly ever (never?) need to use 5th even with the lowered final drive and JDM ratios it has fitted. Obviously everything will wear out eventually but I'd expect the lower gear synchros to fail first. Having said all that it does sound like the 5th gear synchromesh is worn or broken.

Just in case, I'd completely drain and replace the gearbox oil and see if it helps before removing and opening up the 'box.


Would imagine it would be advisable to replace every synchro whatever and inspect\replace gears as necessary.

This would definitely make sense, as would replacing the bearings while you're in there, as most of the cost will be labour to get the 'box out (and re-installed) and stripped to inspect and replace any actual worn out and broken parts.

Good luck with it.

Mark

[gumball]

Its' Tiff Needel isn't it.

[NSX 2000]

I thought I'd add to this rather than making a new thread.

I have the 5th gear synchro issue like Amo had.

I can shift into 5th fine when not driving at high revs, if I rev match / "double clutch" between the shift or just shift slowly. So I guess I'm basically saying it shifts fine if I ensure the synchro doesn't have to do much work.

I have a couple of times purely out of bad habit shifted from 3rd to 5th at high revs and the synchro certainly doesn't like that!

As I don't know the technicalities of gearboxes very well, can someone tell how much work / what is involved to fix this? I've looked at the images supplied by Simon but it doesn't really give me an idea of the scale of the work that is required.

Cheers

Ed

Hi Ed, hope you are well, I'm the last person you want to ask about complicated things like this, so my advice is to ask the previous owner for his thoughts aka forumadmin. If you send him a pm I'm sure Kevin will be more than happy to give some advice or even tell you off for changing from 3rd to 5th:D, I will admit this is something I do on the motorway as well.

HTH

Paul

PS I do know that he is busy with work at the moment so he may take a while to reply.

[markc]

Its' Tiff Needel isn't it.

:) :) :)

Leave the old duffer alone, he certainly knows how to drive a car quickly. I love it when him and JP race :)

Cheers

Mark