Discussion
Was planning on another visit to Hampton downs on Monday. Having suffered from a nasty vibration through the wheel under hard braking in my last session. I had figured the pads were probably wearing thin (although they looked OK when I'd checked the car over the day before). Anyway decided to do my pre-trackday checks today.
THANK GOD I DID.
First pic is how it should look (note the green marker fluid I use to ensure nothing has moved).
Note how in the second picture the lack of green marker fluid is a give away to all not being well. That along with the fact the ENTIRE hub clamping assembly is missing was also a give away!!!
I can only assume that the bolt has snapped as the nyloc nut was fine when I checked it the day before my last trackday but who knows.
Turns out that Lotus upgraded this part not long after my car came off the production line.
from Lotus service notes :
Front Hub M16 Clamp Bolt Set
Standard cars used a front hub M12 clamp bolt set until Sept.1997 (approx. VIN W 1830), at which time
the competition type M16 clamp bolt set was commonised to all cars. If an early car is to be used in a
competition environment with the associated high level of chassis loading, it is recommended that the front
hub bearing M12 clamp bolts be replaced by M16 clamp bolt sets including thrust washers, which allow a
substantial increase in the clamping force applied to the inner bearing races. Updating to the later specification
is also recommended if the front hubs are to be removed for any reason.
Naturally if I had committed the entire service manual to memory I would have upgraded the clamp bolt set a long time ago.
Reading through SELOC there's been a number of cases of wheels coming off after failure of the old assembly!
Moral of the story if you have an early S1 Elise check the front hub to confirm it has the upgraded clamp bolt.
THANK GOD I DID.
First pic is how it should look (note the green marker fluid I use to ensure nothing has moved).
Note how in the second picture the lack of green marker fluid is a give away to all not being well. That along with the fact the ENTIRE hub clamping assembly is missing was also a give away!!!
I can only assume that the bolt has snapped as the nyloc nut was fine when I checked it the day before my last trackday but who knows.
Turns out that Lotus upgraded this part not long after my car came off the production line.
from Lotus service notes :
Front Hub M16 Clamp Bolt Set
Standard cars used a front hub M12 clamp bolt set until Sept.1997 (approx. VIN W 1830), at which time
the competition type M16 clamp bolt set was commonised to all cars. If an early car is to be used in a
competition environment with the associated high level of chassis loading, it is recommended that the front
hub bearing M12 clamp bolts be replaced by M16 clamp bolt sets including thrust washers, which allow a
substantial increase in the clamping force applied to the inner bearing races. Updating to the later specification
is also recommended if the front hubs are to be removed for any reason.
Naturally if I had committed the entire service manual to memory I would have upgraded the clamp bolt set a long time ago.
Reading through SELOC there's been a number of cases of wheels coming off after failure of the old assembly!
Moral of the story if you have an early S1 Elise check the front hub to confirm it has the upgraded clamp bolt.
Edited by iwilson on Saturday 5th December 04:30
Ian! If I'd known you were still running the M12 hub bolts, I'd have given you a good slapping! I'd just assumed you would have changed it!!!!! Yes, certainly any car running track work on semi slicks I'd never go near unless they got the M16 upgrade at the front. Thankfully both of my cars came from factory with the M16s factory fitted. Having said that, I replaced my M16s this rebuild just to be safe, the old ones were a little corroded. It also looks like corrosion's had a bit of a piece to play there in your one too.
Chances are you've completely fooked the wheelbearing as well since you'll have lost the clamping load on it. The hub itself SHOULD be okay so long as this hasn't begun to spin in the race.
Pull the upright off, you can bring it into my work and we'll press it apart and inspect it for damage.
All I can say is that you're chuffing lucky mate, and it's a timely reminder for ANY trackday goer (whatever the car) that periodic safety checks are more than worth the time.
Chances are you've completely fooked the wheelbearing as well since you'll have lost the clamping load on it. The hub itself SHOULD be okay so long as this hasn't begun to spin in the race.
Pull the upright off, you can bring it into my work and we'll press it apart and inspect it for damage.
All I can say is that you're chuffing lucky mate, and it's a timely reminder for ANY trackday goer (whatever the car) that periodic safety checks are more than worth the time.
I would have figured it would have been replaced by now at one of the many professional services it's had. The specialist garage it went to in Holland certainly knew what the car was used for and I can't believe it's still on the original front bearings. Your average owner does not have the service manual or even get involved in servicing their car. This is something that should be picked up by a Lotus specialist garage. And it's pretty obvious since the old bolt is an M12 and the new M16.
I'm a bit pissed by having to miss the trackday now, but more than relieved it didn't result in carnage if the wheel had let go.
I'm a bit pissed by having to miss the trackday now, but more than relieved it didn't result in carnage if the wheel had let go.
Ian - I might have a spare wheel bearing unused in my spares box if Ken doens;t have one to hand.. want me to have a look?
Was wired at the weekend mate. A big crash on Saturday and another monster one on Sunday - went home to spend time with wife instead of hanging around!!!
(Not my crashes I hasten to add!!)
Was wired at the weekend mate. A big crash on Saturday and another monster one on Sunday - went home to spend time with wife instead of hanging around!!!
(Not my crashes I hasten to add!!)
Edited by Richard Gee on Monday 7th December 08:34
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