james.c

Thanks Guy. What tool did you use to cut those off? I blunted a few blades of a hacksaw and got one off. But ran out of blades to get the other one off. Clearly the wrong tool (and / or wrong blades!).

Thanks all. Comments gave me enough confidence that this might be something I could solve with brute force! An adjustable spanner in the back on the wind back tool gave me more leverage. Still took a bit of force but after a few turns i could get it back far enough to slide the back plate in and finish the job.

Thanks - it does sound like I just need apply more force. But I can't set the tool up as you describe as there just isn't enough room inside the caliper as the piston is so far out (see earlier response). I either need to cut the lugs off the back of the disc or find one that is thinner that would fit on my wind back tool. I'll see how I get on with a hacksaw when my clamp turns up!

The gap in the photo is created by two other metal studs on the other side of the disc (in different positions so you can flip it around and use the tool on a different sized piston). Plan B is to see if I can cut them off with a hacksaw (an "essential" delivery of a bench clamp is on its way from Amazon!). That should give me the space to get the plate in. At the moment, even if I position it correctly without the plate there isn't enough space to slide the plate up from underneath.

Thanks all. I'll have another go. Sounds like it might just be a brute force issue and maybe I'm being overly careful! I'll try the hammer tapping technique too and report back. I don't have an angle grinder but plan B is to get hold of a hacksaw to take the metal studs off the back of the back plate (if you look at the original photo you can see that the studs that fit a different sized piston are stopping me from finding enough space!). Some of the videos / articles make it look relatively simple (i.e. not huge amounts of force). But perhaps they are just a little ceased up for some reason. J

Hi all, As lots probably have, I'm trying to do a few simple bits to the car whilst we're in lockdown. Thought I'd try replacing my rear brake pads as I'd not done it before and I could see they were low. Standard Delphi rear pads on a late 2016 620S (if it makes much difference!): https://caterhamparts.co.uk/calipers-pads-discs/668-brake-pads-rear-use-with-4-pot-front-brakes.html?search_query=rear+pads&results=317 There are some good videos and articles about on how to do this: and http://www.alcester-racing-sevens.com/rear_brake_pads.htm....so I thought that even I might be able to get this done. I'd ordered a wind back tool so felt I had all the kit. The first problem that I've got is that the pistons seem to be a long way out. I guess because the rears were fairly worn out. In fact they are so far out that you can't get back plate of the wind back inside the caliper to allow it to brace in order to be able to apply more force to the twist. Hopefully you can see that from the photo below. BTW - you can't even (quite) get the wind back tool in place without the back plate and then slide that on from underneath. However, even with what feels like a lot of force using pliers or the wind back tool (in place but without the back plate) I can't get the piston to rotate / rewind at all. The hand brake is off and I've taken the master brake cylinder cap off. I've even tried with loosened brake bleed nipples to make sure that I'm not working against pressure. Am I doing something daft? I'm not sure what to try next (other than to give up and take it to a garage when all this blows over!). Is there any reason why I might need to be able to take the handbrake cable / hook off? If so what's the technique for that? Perhaps it does just require considerable force to rotate the piston and without the backing plate on the wind back tool I have no chance of even shifting it a few mm. Or perhaps my pistons need to rewind anti-clockwise and I need a different tool. I can't seem to shift it in either direction! Could someone confirm which way they go? From what I can tell people seem to have wind back tools that push in when turned clockwise (the more common way I guess). Any thoughts?! I'm frustrated that I've failed in such a simple task! All part of the learning curve I guess. Thanks in advance for any help. James

Thanks Jim, Much appreciated. I got confirmation from a couple of friends earlier too so went for it (and I've used a marker for a quick check next time!). I've done 2 track days since it all collapsed and nothing was loose this time. Long story but I have my suspicions that it was not torqued up properly in the factory. But the manual does specifically say to check them on the 620 so can't really complain! J

Hi all, I'm spanner checking my 620S before a track day at Silverstone on Tuesday. I had a total failure of the diff carrier this year because I had not been checking the diff and carrier bolts every track day (the carrier sheared off and I had to be rescued from the west coast of Wales!). I'm new to this so just wanted some help to identify the correct bolts so I get the torque right. I couldn't get everything in one photo (sorry!) so I've labeled the 4 bolts in the two images below. My best guess are: 1 = Rear carrier bolt (so from build guide "x2 M10 plain on rear - 47Nm") 2 = Upper differential mounting (??) so 54Nm 3 = Forward carrier bolt (so from build guide "x2 M12 caphead on either side - 81Nm) 4 = Lower differential mounting (??) so 54Nm I'm obviously just worried that I could be completely wrong here and do some damage if I under / over tighten the wrong thing! Thanks for any help you can give. J

Thanks. I'll take a look at that once I've got this sorted!

Thanks very much! I think you're exactly right. Bookatrack spanner checked the car for me a couple of months ago and said that these were loose (one bolt was actually missing!). Since then I've done two track days and the tour of Wales. I suspect that the carrier had developed a fault from the vibrations over the previous 12 months or so and then failed. I'll certainly push for it to be sorted on warranty. I'm slowly learning about cars but its a long road and they don't really make it easy for you. A simple "spanner check" manual for newbies would be great. There is stuff around but you have to search hard and it's tough when you start from a zero base! Clearly I should have been checking the torque of these bolts every track day. Still learning!

My 3 day tour of Wales was cut short at the end of day 2 as a slight banging / movement from the back of the car (and a grinding when off the power in gear!) got worse and worse. When we got the hotel we found that the diff bracket seems to have completely sheared off. It's an18 month old 620S so hoping it should be sorted under warranty (BaT looking at pictures now). Anyone else experienced anything like this before? Also wondering what the chances are that I have damaged the diff over the 35 miles limping back to the hotel. It drove ok (especially under power) which is why I limped it back (also was in the middle of nowhere!) Any thoughts / advice gratefully received! Can't see much on this one other than a loose bolt! Probably the easiest way to see that the metal seems to have failed on either side of the diff. Both bolts are just spinning round as they aren't connected to anything anymore! This is rotated 90 counter-clockwise but you can see that the bottom bolt (right in the photo) is not just connected to the remains of the bracket which is now missing.

My 3 day tour of Wales was cut short at the end of day 2 as a slight banging / movement from the back of the car (and a grinding when off the power in gear!) got worse and worse. When we got the hotel we found that the diff bracket seems to have completely sheared off. It's an18 month old 620S so hoping it should be sorted under warranty (BaT looking at pictures now). Anyone else experienced anything like this before? Also wondering what the chances are that I have damaged the diff over the 35 miles limping back to the hotel. It drove ok (especially under power) which is why I limped it back (also was in the middle of nowhere!) Any thoughts / advice gratefully received! Can't see much on this one other than a loose bolt! Probably the easiest way to see that the metal seems to have failed on either side of the diff. Both bolts are just spinning round as they aren't connected to anything anymore! This is rotated 90 counter-clockwise but you can see that the bottom bolt (right in the photo) is not just connected to the remains of the bracket which is now missing.

Pads being changed at 12. Thanks for the tip. They were really helpful!

Thanks, we're passing through there anyway. I'll call them in the morning and see if they can help!

Evening all, Just turned up at the hotel ready for the first leg of a 3 day road trip through Wales. Just noticed that my rear brake pads are horribly low! Fronts are not terrible so should be ok getting to Bangor (first leg). Where do I start working out what brake pads I need to try and find a garage in Bangor to help me? The car is a standard 2016 620S. Uprated brakes (front??). Not sure if they are standard pads and / or if I have any chance of finding the right pads in Bangor. Any help much appreciated! J

Hi all, We are building a new garage (including foundations) so it seems like a great opportunity to (perhaps) put a lift in the floor for the Caterham. Bit of a luxury I know but seems like the time to do it and obviously it would be great for those quick post track day spanner checks! Has anyone done this who could give me any pointers? Any specific kit people have found worked well (or not so well)? Perhaps things to think about when selecting flooring for the garage so it fits in well. Anything else?! Thanks J

Thanks James, Just replied to the email from Sam to re-confirm as (much to my relief!) I can make that date (just - get back from Amsterdam on the evening of the 9th so a late setup and an early start!). Well done for getting a new date so quickly. Getting a bit desperate to get back on track! J

Update on this having spoken to CC (actually Greg from BaT who was quick to call me back after I posted a note on the website). The guys in the workshop reckon this oil pressure is normal for a 620. Obviously the 10w / 60 oil is a little thicker anyway and it would have been like treacle given the recent temperatures (and my garage is not connected to the house to get any ambient heat). Apparently the 620's do run a higher oil pressure too for some reason. So basically all fine. For anyone with a 620, don't worry if you see it spike into the red (8 bar) the next time "The Beast from the East" rocks up. But obviously take time to gently warm the oil up before thrashing it round the track!

Thanks all. I wish I was able to answer any of your questions! No idea I'm afraid. Factory built 2016 620S. Sadly the club trackday at Silverstone was called off this afternoon due to the weather. However, that means there is a little less urgency so I'll call CC and see what they say. I'll update this post when I hear more as, if it's normal behavior at very low temperatures, it might be concerning for others with a similar setup.

Thanks to the team for ringing round today with the news. It takes a lot of effort to get these days organised so felt bad for the guys as much as anything. First world problems for us! As Steve says, fingers crossed I can make the (hopefully warmer!) day in the summer.

Just took mine out to fill up (back on track at the club Silverstone day on Monday and it's been in the garage for 4 months). Oil pressure was pushing closer to 8 bar when I was pushing the revs up (not to the red line). Obviously it's very cold today. Do you think I should be worried?! Not changed anything over the winter. Edited: Sorry, meant to add that a difference here is that it's a 620S so has the dry sump. I'm using Mobil 1 10w-60 Advanced Full Synthetic Engine Oil.

Yup, I'm in!

Aero on the birthday list and looking to tow the car to trackdays. That means half doors and a tonneau cover are now on the wish list!

Just needs to accommodate an SV. Twin axle (probably) preferred but happy to take a look at anything.

Haha, perfect advice. Thanks John!