S80 gear box issue

[racingmason]

Hi guys
I have a classic mini with an integra type r
Engine and S 80 box with jenvey throttle bodies
I have been having a intermittent problem with 4th gear when changing from third intermittently won't go in 4th gear
If I just take it back to third not all the way in and then try again it goes in
As I said this doesn't happen all the time and seems more problematic on longer journeys
Any advice welcome

Thanks
Lee

 

[Buckyy]

Does it grind or just won't select?

 

[racingmason]

Just won't select

 

[Buckyy]

My guess would be a clutch problem pressure plate might not be engaging fully

 

[racingmason]

But I have no problems with any other gear
And no problem changing down into 4th gear surely this would happen in all gears

Lee

 

[Leej8]

Could be synchro, check that your not hitting anything under car exuast first , but Deffo it's box out for inspection
Unfortunately, should not be two expensive to fix if you fix yourself.

 

[B16Swt]

Sounds like the synchro between 3rd and 4th gear is gone.
They are a common failure on Honda boxes due to the high rpm changes.
Easy fix is replace the synchros and I'd advise upgrading to carbon synchro's.