Did a day at Donington today and the car felt horrid from mid morning, understeer and washing out. Played with the dampers and tyre pressures and it felt better but I was just going slower as I had no confidence in the car.
After lunch it made horrible noise when turning right. Pulled onto the grass and I could waggle the NSF wheel. Limped back and agreed with the TD mechanic that it looked like a shot wheel bearing. Got home and found it was the two M10 bolts that hold on the steering arm were loose (allowing the hub to move).
I always jack up my car and waggle all four wheels vigorously to check for movement before a track day. I also check all suspension bolts over the winter. The car had done 2TDs since being fully checked. So the bolts came loose during the morning. There was no obvious signs on thread lock on the bolts but there was plenty of grease. I always fit them clean and dry.
How often do others check suspension nut/bolt tightness?
I plan to put to get some new bolts (in case they are damaged) and use strong threadlock and marker paint.
The cap head bolts fitted on mine are 12.9. rather than 10.6 in the Deroure Catalog.
I’m not sure about the “pritt stick” thread lock. I prefer the more liquid type which can run around the thread. I put a paint mark on anything I take apart so I can visually check for movement. I think this is better than “spannering” everything which could over tighten them (particularly on smaller bolts).
Waggle check every TD (wheels on). Visual “line” check every winter (wheels off), plus TQ wrench on anything I am not sure about and always the wishbones chassis mounts.
Have I ever found anything loose before?..yes. Rear hub, toe links, rear wishbone mount. I have never had to “fix” anything I have worked on. I sometimes wonder if part of the problem is that mechanics do not use a torque wrench or thread lock and they put grease on the threads (or fit them dirty).
I used to have a bit of a corner by corner routine, for checking all of the suspension bolts. I used to do it before each event. I could do each corner in a couple of minutes and it just made me more confident knowing I had a spanner on every fixing that could result in me flying off the track if something went wrong.
That’s probably your issue/problem
You cannot get enough torque on the 12.9 for them to tighten properly, they are also brittle compared to the correct 10.9 bolts…
A normal allen cap bolt from a nut and bolt stockist will be 12.9 rated, you can’t buy 10.9 off the shelf.
Lotus must have the 10.9 cap head bolts made specially for them. Buy them from Lotus and replace them often, they cost pennies in comparison to a failure…
I had one come loose which caused the other one to shear at Zandvoort last year, fortunately still had a couple of threads on the loose one which bent but didn’t part company…
Bought a Lottery ticket that night but guess I’d used up all my luck already!
