5th Gear crunchy

Prof · August 13, 2008, 10:32:51 AM

I get a crunch when selecting 5th gear. I\'ve tried it form 4th and 3rd - in case it was the \'gate\' that was the problem - but it happens every time. All other gears including reverse (when stationary) are selectable without issue.

I\'m guessing it\'s the 5th gear synchro that\'s gone. Now some questions:

1) If it is the synchro is it easily fixed - how big of a job is it ?

2) If it\'s some other issue - what might it be ?

3) Would it be cheaper to put another box on the car, rather than repair this gearbox (as far as I know, the current box has been on the car for all 19 years of it\'s life).

TiddlesRX7 · August 13, 2008, 10:39:33 AM

Dunno really. I\'ve been trying to avoid this as mine is the same. And it the second box that i\'ve put in it. Both had the crunch going into 5th.Doh. I\'ve got another box to try as the cost to rebuild the box is around Â£500.

Prof · August 13, 2008, 10:51:44 AM

Quote from: adereed;524009Dunno really. I\'ve been trying to avoid this as mine is the same. And it the second box that i\'ve put in it. Both had the crunch going into 5th.Doh. I\'ve got another box to try as the cost to rebuild the box is around Â£500.

Ouch - I had a feeling it might be pricey - gearbox rebuilds usually are - even if it\'s only 1 cog that needs replacing - they usually seem to want to service the whole box.

Is this a common problem on FC\'s then ?

TiddlesRX7 · August 13, 2008, 01:11:16 PM

I think it must be. Like I\'ve said i\'m on my second box now and both were the same. I just hope the 3rd one I have is ok!

pdtaylor18 · August 13, 2008, 02:14:47 PM

Dave,
3rd was crunching on my old box, replaced gear oils, bled clutch etc but in the end I just changed the box and all was ok.
Ben is breaking his car so he might sell you his. I d have a spare but gonna keep it for the very same reasons. For now just keep the revs as low as posssible, even if it means waiting a few more seconds between that change, it will last a bit more longer.

L18M · August 22, 2008, 02:11:00 AM

when you say crunch, is that like a trying to change gear but without ur foot all teh way down on the clutch type of crunch?

i think i either got box probs or clutch probs as the box is really notchy (not smooth) when changing to any gear (and it has nothing to do with the short shift as was the same using non-short shift stick) and sometime when i change from 2nd to 3rd the gears grinds as like i\'ve nt put the cluthc down fully.

anyone got ideas which is causing the prob or if its both?!

think the fd has same ratios as the fc box. can u fit an fd box into an fc?

Prof · August 22, 2008, 08:15:39 AM

I\'ve got Ben\'s box - so hopefully this is no longer going to be a problem.

If you are getting \'crunches\' on most gears then it could well be the clutch is on it\'s last legs. My clutch was only recently replaced (Feb/March) so it\'s hardly worn. The crunch noise is similar to when you haven\'t put the clutch down fully - that notchy feeling could just be that you are low on oil either in the gearbox or selector housing (if you take the gear knob off, and lift the gear boot and the 2 rubber rings under it - then remove the 3 bolts that hold the gear selecter lever - lift it out and check the oil in there - if it\'s dry that won\'t be helping.

David Nock (RIP) · August 22, 2008, 02:11:15 PM

I\'d try full synthetic gear oil 1st before changing the box. Also I would try double declutching upwards, which is what had to be done on the old crash boxes before synchros came in.
Mind you, I\'m a buggxr for trying to keep old things going, even when they really are due for a major fix.