SimonK

I am about to do this mod because after the rebuild I've had three random 2nd gear pop-outs. I did not have a pop-out problem prior to the rebuild. I know all internal pieces are good, my builder showed me, so I am fitting gbox detent as a preventative measure. Clearly my builder got tolerances slightly off. I have no idea how? He only changed main shaft bearing and first three synchros. (1-3). He reused my shims.

What concerns me is that when I was researching gbox detent, (all users happy with it) I found this statement from one of the UK rebuilders. Does it sound right or is it BS as he wants to drum up his (more expensive option) rebuild business?

This is what he says:

"Just a note on that detent... it makes the gear selector over throw the gear into all gears not just 2nd gear.. this is not the correct way to modify these gearboxes as now you have 5 other gears that are not at their correct engagement point. They are being overthrown onto the dogring and this can damage the teeth and sliding sleeve as it crashes down onto the gear! We have seen similar things and found 3rd/4th dog teeth rings with pieces broken off. If you want it done correctly you need to modify the gearbox internally".

Damn! Tanx.

Kevinmacd

SimonK - You may wan to have the shifter cable adjustments looked at.

SimonK

I told this to my gearbox rebuilder but he said very unlikely. I am not sure he is right. When you take gearbox out can cables unadjust themselves? What is the proper adjustment? Any pointers?

PAULUNM

I'd 2nd this.

Before I had the detent installed, I was never really sure if I was actually in gear, after- there was a fairly audible metallic thack into each gear- the way a transmission is supposed to sound IMO.

Now that I have the 997.2 GT3 shifter installed, perfection.

SimonK

I already have short shifter. I have a metallic thack when slotting in. If cables aren't adjusted properly could they be out by such a minor amount in order to cause 2nd gear pop-out. I presume they would have to be to tense so when car unloads they would cause pop-out. But wouldn't unadjusted cable cause problem with all gears?

Kevinmacd

You did not have the pop pop out before the trans rebuild. So either the rebuikd was not done correctly or sonmething changed. So what does it take to check them by someone else other than your gearbox guy.