180sx 5speed , coming out of 4th gear .

[ekjim]

I've been having a problem with my car since upgrading the clutch to an Extreme twin plate. When I took the car to get dyno'd after fitting new cams, it made the same power with same boost, but picked up 50ft pounds of torque in the mid-range and about 420bhp at the flywheel. The problem began on the dyno when coming off the throttle in 4th gear, it was coming out of gear, this was the same on the road. I'm thinking it may have been the slave cylinder rod, I tried extending this but though it made going into gear a bit easier, it was still the same when coming off the throttle in 4th. I know I will have to upgrade the box at this power but would like to figure out what was causing this.

[green_rs13]

is the engine rocking and the shifter bashing the hole in the tunnel?

[ekjim]

No, thanks for the reply but I'm quite sure it's not that.

[s200rat]

its likely you have wear in control rod grooves or the ball bearing. Or the spring that loads the ball bearing has weakened.

on the gearbox there is the centre adapter plate. within this there is 2 or 3 bolts (from memory) which cover the check balls/spring which run against the selector fork rods. The selector rods have machined groves in them and provides a force to stay in gear via the ball detent. If the machined groove has worn or the detent plunger has worn then it would be easy for the gear to come out.

Thats where i would have a look / replace spring.

[ekjim]

Thanks for the reply, mate, this has made my mind up for now. I'm going to take the gearbox out and get this checked and hopefully sorted and put back in till I can afford a 350z gearbox.

[green_rs13]

does it feel ok when shifting into 4th? if the spring was damaged or the ball bearing stuck it would feel weird. i had a box where some spastic didn't put the ball bearing in and it shifted like 4th didnt exist.

you can get to the balls/springs with the box in situ but it depends on what your gearbox tunnel is like.. if you need some new selector rods/springs/ balls let me know as ive loads of this type of stuff.

[ekjim]

It feels fine going into fourth gear, its only when coming of the throttle that it comes out of gear. Thanks for the offer of parts ill post up when I've got the gearbox out.