I have a 60 series box out of a late model Nissan Champ (A14) 5 speed in my B110 that I race with, its held up amazingly well besides getting jammed in 4th twice now...

First time was on the track, leasurly down shift and it just wouldnt budge, i tried everything but to no avail, took the box out and took it to my transmission guy, he said one of the selector bolts (10mm head i was told) came loose, he just nipped it up with some loctite, I put box back in and was on my ways, lasted over 18 months now (20 race events including enduro's) and about 10 000km's...

On the way to work last week I was giving a V-tak-yo guy a leason on old school power, took her up to 8400rpm in 4th and as I went to 5th it would not budge, same as last time, drove it home in 4th (real fun with a 2.8kg flywheel) stripped the box out and opened it up, besides the hate of gear oil I could see nothing, the only 10mm head bolt is the one that holds the wedge for the selector, it was tight and in place... after fighting with the box trying to get the tail housing back on for an hour i admited defeat... besides that the parts shop gave me the wrong clutch, this one is 10mm larger disk and doesnt suit my flywheel...

Taking it back to the trans guy on monday, just wondering if anyone else has every seen or heard of this happening? changing clutches every time sux!

One thing im happy about is that the gears look 100% new having only ever ran on Redline light weight shock proof (smurf blood)