A missed shift will ruin your transmission.  As strong as they are, even an E-series box doesn't deal with ham-fisted changes well at all...
 
 

My transmission is already very worn out from lots of track days and drag racing, so it doesn't feel very good on the street anymore, but I've got to a point where I'm used to it so I don't stress about it as much now. I was going to rebuild or replace the transmission ages ago, but I decided to hold off for now because it'll just get worn out again anyway (at least while I'm still attending track days and drags). If it does happen to fail in a more serious way, then that'll be an excuse to rebuild or replace it immediately.

Maybe follow in Lockies footsteps with what he has now done transmission wise.

Well, sure enough, my gearbox did fail at the drags!
To avoid paying for a tow truck, I drove almost 30km from Sydney Dragway to Advance Motor Mechanics with only 1st and 2nd gear working.
As annoying as it is, it was really only a matter of time (I could tell because the gearbox had felt really crap for ages), and apart from the repair cost I'm actually really excited to finally have a gearbox that feels good again.
Lockie had a spare gearbox in really good condition, and he's a good friend of the guys at Advance Motor Mechanics, so I decided to get them to swap that complete box into my car (with my Quaife LSD swapped into it first).
 

Nik_Lee
Maybe follow in Lockies footsteps with what he has now done transmission wise.

I had a good chat to him when I picked up his spare gearbox, and when I found out the enormous amount that he spent on his new gearbox setup, it then became apparent that something similar would be completely out of the question for me at this stage haha.
Since my car is still a street car first and foremost, I've always been against the idea of having straight-cut gears (due to the loud whining noise), or dog engagement instead of synchros (due to the abruptness and loud clunking noise on each gear change).
After my gearbox failed this time, I did start to seriously reconsider, because a dog engagement gearbox would eliminate the synchro issues. I was starting to become OK with the idea of an aftermarket gear set for this reason, but in the end I decided that I didn't want to spend that much right now, and I knew that it would result in having my car off the road for much longer than I'm willing to accept at the moment.
If I can come to accept the cost of an aftermarket gear set, then I could maybe look at doing that with my broken gearbox, while I continue driving around with the replacement OEM gearbox for now.
Yesterday I was made aware (via the Hux Racing fb page) that 'Liberty Gears' (in the US) are able to modify the stock gears to convert them to suit dog engagement instead of synchro engagement. As far as I understand, they chop off part of the stock gears and weld a new part onto each gear for dog engagement, and they provide their own sleeves and forks to complete the conversion. That could be another option, but I would have to do some research to see if anyone has had any reliability issues with them.

Rob. Have you looked into the possibility of buying a brand new E153?
Mandalay did this a few years ago and I don't think it was all that expensive.
Problem we all face is that these old cars are worth bugger all compared to the cost of maintaining them.
I doubt any of us has ever driven a brand new one and they have certainly proved to be robust in handling a bloody lot of torque even when old and buggered.  You could only justify doing this if you were intending to keep the car long term.

$2700 USD plus shipping.

https://twosrus.com/catal...35&products_id=379

The idea of buying a brand new OEM e153 was already thrown around in this thread when I started complaining about my gearbox a few years ago, and back then I gave it some serious consideration, but it's no longer an option that I'll ever re-consider.
The used box that is going into my car now, appears to be in very good condition, and when I get the car back I'm confident that I'm going to be very happy with how it feels for regular driving.
However, I've come to realise that if I want to retain an OEM e153, then I either have to shift slower than I'd like to at high RPM, or accept a lot of synchro wear.

I have a stock E153 and I shift VERY fast, so you don't need anything fancy. I have upgraded joints at the shifter end and brass bushes at the gearbox end. The shifter is an ebay short shifter.
My clutch plate is 4 Puck and the pressure plate is upgraded stock. The clutch feels like a stock road clutch I.e not button

Rob, adavanced motor mechanics at yenora?

Phiz
Rob, adavanced motor mechanics at yenora?

Nah, different place.
Advance Motor Mechanics in Strathfield South.