Moving forwards....and backwards....

Literally! I took a step closer to getting this thing moving last week.

Following a discussion on the CRC I became aware that there were more options open to me with regards to a gearbox. I had always thought that the only way to go was with a new Tremec TKO 600 box, I always dismissed using a 2nd hand box as too fiddly to get working and too risky for reliability. However I have been enlightened as to the benefits of fitting a used Getrag box.

The first concern was ease of fitting. Well BAE are developing a bespoke bell housing for the 302 to mate with the Getrag box so thats that issue sorted.

My next issue was reliability. Well I am now informed that many people are driving around with more powerful engines than mine and are quite happy with a Getrag fitted. Most with only the front and rear seals having been replaced before fitting so that looks like not being an issue.

With this in mind I set out to find a suitable Getrag box from either a BMW or JAG, the JAG being the preferred box due to the gear ratios.

I had been advised via the CRC website that the ratios are as follows:


More on ratios later.

I was contacted by Pete in Bristol (fellow CRC member) who offered a box for sale and after an interesting morning discussing all things, and checking the gearbox apperaed OK, I drove aware with said box acquired.


All forward gears select OK but it currently wont lock into reverse, now some of that might be down to it having no oil in it and also that I don't fully know where reverse should be!

Before doing anything to the box I decided to re-visit ratios to make sure I was happy. I managed to find a copy of the Jag service manual for the 3.6 XJS from which I was informed the gearbox had originally been taken

I found that the ratios were slightly different to those I had been advised previously, ratios and speeds in red are for the Getrag 270 box which I believe this to be, unfortunately Getrag helpfully do not appear to mark this on the box anywhere!


(double click on image to see readable version!)

So plotting the various box options together I can see very little difference and hopefully little difference to driveability.


The box is in need of some work so my first job was to remove the bell housing. Four nuts undone and off it came.


Next up I will remove the metal work for stripping and painting, clean the box fully and then consider if I need to paint the gearbox casing.

First job though is to get some oil in it to soak things a bit. Then I need to replace the front and rear seals but Ill only do that once its soaked and I've managed to get reverse operational otherwise its a pro rebuild at £250 plus!