A bit of a weird one. I get a crunching (sensation no noise though) when executing fast gear changes from 3rd to 4th at 6k upwards. If I change gear slowley (still @ high rpm) no crunch.

Doesn't happen in any other gear. Any ideas?

Thanks

AC

 

Classic signs of failig synchro's..... sounds like new baulk rings required!

 

Thanks M8.

AC

 

I have the same problem..though have no idea what a synchro's is....


--Sam

 

The synchromesh will synchronise the cog speeds to allow for an easier gearchange. A bit like revoling door in a hotel you walk quicker if the door is spinning quicker & slow down if it is going slowly. And you get through without "crunching" yourself

Which in principle is the same for changing gears.....

 

i get the exact same thing sometimes in mine when changing quickly at hi revs from 3rd to 4th, how this solved? nothing major i hope

 

as long as you don't consider taking the box out and replacing the synchro rings major... sorry!

 

i dont know smartarse! is takin the box out and replacing the synchro rings major then or what? pricey or do you actually know?

 

never taken a scooby box out but id imagine 30quid per hour min for someone who knows what they're doing - thats gonna be upwards of 150 just to take the box out and refit. then synchros are what? £15-£100 each? i have no idea tbh for a scoob

plus a few hours to fit... it's gonna be £350 at the minimum id imagine. thought of a new (well secondhand) box?

edit: have any of you tried changing your box oil?

 

got her fully serviced when she came in last month all oils changed..runnin fine, just sometimes as i said when flying from 3rd to 4th it crunches a lil bit, its out in the mechanics having the downpipe fitted so il say it to him tmrw to see what the story is..

 

yeah sounds like the *beginning* of synchro trouble. be ok for a while - get saving!

mine baulks if i go 1st to 2nd too quickly sometimes but i'm not too worried at the mo...

 

This problem has been fixed. No gearbox or synchro required. Changed the gearbox oil from Silkoline to Castrol and it went away.

There are quite a few threads on this so I guess it can be quite common.