I have a new problem with the 5-speed gearbox in my '04 RS track day car. It "falls out" of 3rd gear fairly often on the track, when I am not hard on the gas. If going through a turn with a light amount of throttle, the gearshift lever just moves itself out of 3rd gear into neutral. This is very unnerving when I get on the gas exiting the turn, only to find out that I am not in gear.

This never happens on hard acceleration in 3rd gear. If WOT, or even 1/2 throttle, the lever stays in 3rd gear. And it never happens on the street.

The gearbox has been rebuilt once by HB Mitsu, probably almost a year ago. They replaced all the synchros, hubs, sleeves and 3rd gear. It has run a lot of HPDE track days since.

Any ideas?

 

do you have a short shifter?

 

No.

 

sounds as if the clutch is not fully engaging. Stock clutch? Maybe spring came loose

 

ACT clutch. And it only happens in 3rd gear, so it would seem more like a gearbox problem than a clutch problem to me.

 

either the gearbox or the shifter is not aligned right. Usually you have that problem with aftermarket adjustable shifters. That's why I asked.

 

It is the synchronizer inside the trans.

 

Gotta love the mitsu rebuilds!

 

Not that I'm glad to see you have tranny probs, but it confirms what I'm going through with my car. Mine is getting progressively worse and I'm pretty sure I don't drive it as hard as you. If I decide to keep my car I'm gonna have to get a Shep or TRE tranny. I haven't heard anything good about dealer rebuilds. I am guessing my stock clutch had a little to do with it also. I had the stock one checked out a few months ago and had a stiffer disk put in to see if it would help, but I think I'll need a whole new aftermarket clutch assembly too. Good luck.

 

At least HB Mitsu rebuilt the gearbox on warranty

 

this is typically a "slider" problem- or sleeve as you said. I'm not sure if slider's the correct name, but it's what the shift forks engage onto. It usually does not disengage on acceleration, only decel or coasting when not under load like you said.

 

is oil fully filled? happened to me the oil was not fully filled, got heated and kept on coming out, but it was my 5th gear

 

Time to send it back out, the shops that I know of that do great trans work are TurboTrix, Shep, and TRE.

Sucky luck man.