Friday, 7 October 2011

Caterham Academy 2012 - Build (Day 8)

Day 8:

So today was supposed to be a good day, but very rapidly turned into a very frustrating one was bound to happen at some point. Basically I spent all day trying to get the diff in, only to find out that after 6 hours work I need to take it out again due to an error in the build manual!!!!!!

I have a new BMW diff, which is supposed to be much quieter than the old Sierra diff, but proved to be a bit of a pig to fit. I got the diff onto a trolley jack and into position reasonably quickly, but the three retaining bolts that hold it into place didn't want to go in. I could get the bottom two retaining bolts in OK and the spacers between the diff and carrier in with a bit of jiggling, but the top one was an absolute pig. No matter what I seemed to do the diff and the carrier were out of alignment by about 1mm. I went round the loop of tightening, untightening, shifting, lifting, jiggling and generally shouting at the diff three or four times before phoning Caterham, whereupon I was told to encourage the top bolt in with a hammer!

Eventually after much blood and sweat I got the diff in, all of the spacers properly sorted out and the retaining bolts done up, only to look at the paperwork that had been hanging off the rear frame in the plastic bag. I had removed it that morning and not looked at it, instead following the build manual as I had been all along. In it were a set of installation instruction for the diff that were different from those in the build manual and it was at this point that I lost my sense of humour. The new instructions, for the BMW diff rather than the Sierra diff, require the handbrake cable to be installed the opposite way around and for a different set of washers to be used on the retaining bolts, neither of which seem like big things, but they do require the diff to come out again!

I am taking the day off tomorrow for a family event and will come back to it again afresh on Sunday. Hopefully the whole process will be a lot quicker next time around now I know how it all goes together, but it really is not a job I want to do again! Oh well, onwards and upwards.


  1. Try having to lift it in twice (took it out because I forgot to put the drive shaft in first) by hand. Scariest experience ever having an oil filled diff hanging over your head and chest.

    I see your drive shaft is already in... good.

  2. ::sympathy::

    Caterham also suggested to me that I took out the flanges as they can be a pig to remove once the diff is fitted. TBH, it was quite hard to take them out anyway, but with the diff on its side we used large spanners leaning on suitably-sized sockets acting as fulcrums. One on each side to give a uniform pull and they came out smoothly - but have some newspaper underneath to catch the oil.

    The funniest bit of the new instructions is the last line, I think, where it says "time estimate 45 mins". If only...