Monday 26 August 2013

Day 5 (Full Day)

With it being the August bank holiday, got the opportunity to spend another full day on the car. After a leisurely morning (well we were working on the car until 11pm the day before), we started to get to work on the car at around lunch time with no real preconceived ideas about exactly which bits we'd try and get done.

The engine and gearbox had finally gone together the day before so it seemed to make sense to try and get some of the remaining preparation work done so that the engine could go in as soon as we had a hoist available. Unfortunately with HSS tool hire closed for the weekend, it was looking like putting in the engine might have to wait until they reopened again the following week. So, back to the story as it unfolded:

Engine Prep

We began by looking at what else we needed to prep on the engine before it could go in. Caterham have done a pretty good job of adding most of the required bits to the engine already so the Alternator, starter motor and various other bits are already fixed to the engine. Reading the relevant section in the manual suggests that the starter motor and the Alternator both need to be removed before trying to fit the engine so wisely we ignored that advice and decided to see if it would go in with those both still attached (it won't but more on that later). There is also mention of attaching an L-shaped hose to the water jacket on the engine. Unfortunately the diagrams had all dried up in the manual by this point so its not entirely clear what pipe arrangement to use (Edit - Full diagram was created once it had gone together - see Days 7&8 for full overview). Some comments from fellow forum goers suggests that the water rail may have been removed completely now and the pipe arrangement changed to accommodate. I can feel a call to the factory coming on next week to confirm.

Handbrake and Handbrake cable

We decided to give ourselves a simpler job to do to get the day started on a positive note and get us stuck back into the build so we had a go at fitting the handbrake and associated cable. With no Diff currently in the car we felt it would be quite easy to run the cable to the rear of the car at this stage and indeed it was. Fitting the handbrake itself is reasonably straightforward and again you spend more time looking for the relevant bits to bolt it together than anything. Unfortunately we failed to find the bigger of the two clevis pins that you need to fix it together so have had to resort to a second hand bolt and nut for now until I can ask Caterham for a replacement.

Bolt in place of Clevis Pin (Middle of shot)

The only other slight complication is the arrangement of what looks to be a switch for the handbrake. There is only a single connector to attach to the switch and yet there are 2 spade connectors that would readily accept the connector. I went for the one in the middle and will no doubt be coming back to change it to the other terminal at a later date. Still I've got a 50% chance it's right.

Handbrake switch

And that was it, it was time for lunch. Today we were home alone and decided to play it safe after yesterdays debacle and opted for some simple toasted sandwiches, mmmmm.

Then it was back to the Assembly Guide to see what other jobs could be usefully undertaken whilst I had the additional help of Leon. A quick check of that and also the forums suggested that we could look to get the dreaded differential in so thats what we decided to have a go at next.

Differential and Prop shaft

I'd heard lots of nasty stories about this particular job so naturally I feared the worst. The diff itself is quite a nicely packaged arrangement, the carrier in particular being quite compact. Taking it out of the box however confirmed that although reasonably small, the thing weighs a considerable amount.

I'm no anorak when it comes to Caterham diffs but my understanding is that it's a BMW diff with, in my case, a 3.9 ratio LSD in it. Not sure exactly which type of LSD Caterham have fitted to it but believe it may be a Quaife? I've also heard some horror stories about the rear plate not being of great design with some owners reporting that the back of the differential has been hitting the Dedion tubes in some of their cars with suspension fully compressed. I'm not sure if I have the new or old type of carrier but Caterham have assured me that they will swap it over to the new type when they do the post build check if its the old.

Rear Differential and carrier
So we set about trying to get it installed and I was thankful that we had 2 of us doing it. On the advice of those that had done this job before, we ignored what the manual said slightly and opted to fit the lower 2 bolts in first (copper slip galore!), leaving the top of the diff in place by locating a couple of screwdrivers into the top mounts. We then set about measuring how central the diff was down at the lower mounting holes and began to take the left and right lower bolts out one at a time in order to add the necessary washers. We were quite pleased with our progress on this bit, it taking no more that 30 minutes with the pair of us shoved underneath the car. A measurement confirmed that we had it exactly centered at the bottom.

Note to others doing this job - just make sure that the brake lines aren't fouling the diff and that the connectors to hold the brake line in place on both sides are located in their relevant slots. The  adjuster (white plastic thing - see image below) locates onto a plate welded directly to the diff carrier.

Then it was time for the top bolt and oh my days was this a pain in the arse or what. The fact is that the tolerance on the top mounts attached to the chassis must not be that high as although we could get the bolt in (top right mounting) we couldn't get the bolt to go through to the other side as the alignment was quite a way out. After much swearing (sorry to my neighbors) and clever use of a jack to push the bottom of the diff up slightly we were still a good 3mm out. If I hadn't read previous posts on the forums regarding this job I'd probably have been more worried at this point but apparently it's quite common and the best tool for the job is simply more welly (Clarkson would love this job). So it was out with the soft faced hammer to 'give it some'. After a couple of hefty blows the top bolt was through - yipeee!

We did our best to add washers either side of the top bolt to try and sort the alignment out but to be honest there wasn't a lot of space to add many washers and the few that did go in required a bit of a hammer to get them to go. Ive taken an initial measurement and it seems to me like the diff could be as much as 0.5cm out of true alignment at the top and yet perfectly aligned at the bottom bolts?!? - I think I'll go back and take some more measurements this morning just to double check. Here's hoping I don't have to take it out again!

Rear Diff Top Bolt finally in

Despite it having taken the best part of 3 hours to reach this point we were feeling really rather smug at what we'd accomplished. I then promptly smacked my head on the corner of one of the lowered floors as I tried to crawl out from under the car and so the balance was restored


At this point we felt it prudent to put the prop shaft into the transmission tunnel so it was in the right place before the engine and gearbox were added. I'd heard too many stories of others forgetting to do that only to find they had to remove either the engine or diff again later to get it in! We just left it hanging next to the diff for now.

By this point it was 5pm in the afternoon and time was moving on but as luck would have it, a very kind gentleman who lives close by kindly offered us an engine crane to use and said we could pop over to get it if we wanted. By 6:30pm we were back home again with it and thought why not try and get the engine in? So thats what we did.

Engine and gearbox fitting

With the crane quickly erected it wasn't long before we had the engine and gearbox swinging free and we began to try and lower it into the chassis. With the engine and gearbox already attached to one another we needed to achieve quite an angle on the whole thing. We also found that we couldn't get the  engine high enough (would have hit the crane arm on the roof) to clear the front chassis cross members so in the end resorted to dropping the car a considerable amount at the front using some conventional axle stands. Then we began to lower it all in being careful to go very slow with it all.

Slowly slowly creepy creepy

Nearly there

Unfortunately it wasn't long before we ran into some problems, the main one being a lack of clearance. The whole thing is an extremely tight fit and eventually despite our best efforts we admitted defeat and removed the Alternator to make some more space. Even then it was still pretty tight.

For those not sure, the tensioner is at the top right and just needs turning with a socket to slacken the belt right off. Just remember how it goes back on for later!

Removing the belt
Space left once Alternator removed

And that gave us the remaining clearance we needed to get it in. I'm pleased to say that our hunch about not having to remove the starter motor proved correct so that was one thing we were pleased not to have to refit later . Using a process of lowering the engine slightly at the front whilst progressively raising the end of the gearbox in the transmission tunnel (using a jack) and exercising plenty of patience we got the job done.

Some potentially useful tips for anyone else struggling with this process.

  • Consider removing the washer bottle off its bracket - we found the engine mount on that side was fouling it and we didn't want to wreck it. Its possible (though fiddly) to refit the bottle to its bracket once the engine is in its final resting place.
  • Consider refitting the Alternator when the engine is not quite fully down into the engine bay and its weight is still supported by the hoist. There was good access from underneath to do this
  • Have someone doing the lowering at the front whilst someone is under the car at the rear to raise the gearbox over the rear gearbox mounting point and to ensure that the end of the gearbox locates properly into the propshaft as the engine is lowered

Gearbox about to connect to propshaft

Redoing the Alternator from underneath

Engine fully home

Getting the engine mounts located using the supplied bolts into the rubbers attached to the chassis proved quite a challenge. Its easy on the exhaust side as clearance isn't an issue with the primaries currently missing. On the other side though it was a pain. In the end I resorted to doing that one up from underneath the car using a large allen key. There was no way of getting a socket in there let alone the torque wrench so I resorted to a spanner located onto the end of an allen key to give me the leverage I needed to get it nice and tight.

Finally (and it was midnight by this point), we refitted the washer bottle. Again a right pain in the arse and I can't help but feel that a different type of bracket would make the whole process a fair bit easier but its back on the car finally and it was off to bed for a well deserved rest.

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