S2 wheel bearing.

[BiggestNizzy]

Socket purchased, see you tomorrow G?

Yea no problem m8

[pete]

You'll need a suitable torx socket to remove the three bolts that hold the bearing unit to the upright and a 34 or 36mm socket to undo the driveshaft nut (think it's 34 but not 100% sure off the top of my head).

You'll need an impact driver or drill to remove the grub screw that holds the brake disk to the hub flange, unless you've already replaced rear disks in the past and have already drilled out and discarded the grub screw.

You'll need a new drive shaft nut, a new split pin and a torque wrench capable of reaching 220Nm (which is the drive shaft bolt tightening torque) - don't get this wrong or you might be overtaken by your wheel, especially if it's on the pax side. If you have two torque wrenches do it up with both (i.e. to whichever one gets more torque for that setting - it's at the upper range of the average 1/2" drive torque wrench).

You should also use a 3/8" drive torque wrench to tighten the torx head bolts back to 90Nm when fitting new bearing unit. 90Nm is quite a lot and access is a bit limited, hence using the torque wrench rather than the usual "that ought to be tight enough" approach. You do not want these bolts coming out. I would refit using a thread locking compound for good measure in case you under-torque them.

Some time spent making sure your tools fit well is going to save you a heap of grief should you round off any bolt heads.

Procedure is:

Jack up securely, wheel off, handbrake on, in gear for good measure, remove split pin and undo 34 (or maybe 36) drive shaft bolt. If you struggle to keep wheel from turning, pop out center cap from wheel, refit wheel and then lower off jack; with the car chocked, handbrake on, in gear, you should be able to undo the nut.

With the car jacked, wheel off, drive shut nut loose, remove the brake caliper (one cap head bolt and one 17mm normal head bolt) and stash it on the wishbone somewhere to keep it safe.

Remove the brake disk (may require WMD to remove the old grub screw).

Unbolt the three torx head bolts that hold the bearing unit to the upright.

Chuck old bearing away (don't forget to unplug/replug the speedo sensor if doing pax side).

Fit new bearing, thread lock and tighten the three bolts back to 90Nm.

Refit disk (and grub screw if not mullered) and caliper.

Fit new driveshaft nut & tighten to 220Nm, then insert new split pin.

Wheel on.

Job done.

Cheers,
Robin

We haven't used a new nut for the driveshaft, (the old one was fine). is this wrong?

re the rounding off bolt thing. Yeah we did that, any idea where we could get a new bolt on a Sunday?

[robin]

I would have thought the bearing would come with a new nut. If it didn't, and given that the manual doesn't say to replace the nut, I would guess you'll be OK with the old nut - there is a split pin to stop it unwinding, so you have some insurance

I wouldn't even consider using anything other than the OEM part for the bolts that hold the bearing unit to the upright. Judging by the torque setting I would guess they're a high tensile type bolt. Bolts are done up to a torque setting because that is the point at which the bolt stretches and jams in the threads; the point at which that happens defines the resulting clamping force between the two mating faces. In this case, the clamping force is safety critical (your car is suspended on the four mating joints between the four bearings and the four uprights). Only a mad person would choose to source a different bolt without understanding everything involved and thus being able to select something appropriate. Order a dozen from Lotus, fit however many you need now and keep the rest for when you change other bearings or other SErs are in need ....

In the meanwhile you could use a standard 8.8 type bolt to hold the joint secure BUT I wouldn't drive the car at more than 30mph ...

Cheers,
Robin

[BiggestNizzy]

I think they are 12.9 (high tensile bolts) but they look like M12x1's I should have checked the pitch though but M12x1's does make sence as it will stop you putting i'n std B&Q bolts made of cheese, I think I will get a cap head screw and check pete

[robin]

Yes, they'll be 10.9 or 12.9 but the point is that using 8.8 will not damage anything while you source the proper bolt - I really think that if you're sourcing a replacement bolt you may as well just get it from Lotus (it will cost all of a couple of quid - a lot for a bolt, but f*ck all in the scheme of Lotus ownership!).

Materials choice for suspension parts is tricky stuff ...

Cheers,
Robin

[robin]

Part number for correct part is:

LA116W1170F price 57p.

Cheers,
Robin

[pete]

Part number for correct part is:

LA116W1170F price 57p.

Cheers,
Robin

You are, as always, a saviour Robin.
Will call Lotus tomorrow. (I wasn't going to use a non-standard bolt, just hoping someone had a spare! I'll order a handful for the next time.)


Just keep your fingers crossed they actually have some

[BiggestNizzy]

Give us a bell when the parts arrive and we will finish this rather long drawn out job.



you should have known. when I get involved these things take way longer than expected

[pete]

not at all, I am always a curse on such projects...

[pete]

none in stock. 2 day lead time from Lotus.

Any other ideas?

[VXJON]

Vauxhall ??

[jj]

What bolt is it you need, I am a bit confused - I ordered a couple of the 10.9 bolt that goes through the upright and holds the rear caliper on (I think it was about 80mm long from memory) is that the one you need? Its half threaded / half not. I still have one left somewhereif thats the one you need.

[BiggestNizzy]

It's the bolt that holds the sealed wheel bearing/hub unit onto the Hub carrier They look like M12x1 or something altough I could be talking crap and they are Std M12x1.25's.

I will get some STD M12x1.25 Cap head screws (12.9's) I think they are 40 long but will pickup 30's and 50's incase

[pete]

S'OK I've ordered a handful from Lotus (they are 50p!) and I've got lifts sorted for the rest of my cycle...

[BiggestNizzy]

Just let me know when you get them in & are free this time it will take no more than an hour all the crap jobs are done.