Lotus Europa Community

I’ve never heard of one but there are alternate ways of locking that nut. My machinist drilled an axial hole at the threads of the nut and the outboard shaft, tapped it and screwed and loctited a set screw or grub screw in it. It seems I’ve heard of other locking methods but I’m drawing a blank at the moment.

D washer = lock tab washer

The most common way they loosen is the collapse of the mild-steel, inner spacer.  Another is when they weren't tightened properly.  You can't just tighten the nut.  You need to tighten the nut, drive and corner it hard, tighten the nut, driven corner it hard, and keep repeating until it's stable.  Then bend the lock-tabs.

This is why you use 635.  It is a slow setting compound and gives you time to assemble and go through the tightening process before it sets.

Thank you everyone those are incredibly useful answers and links.

BDA, the drilling through and or use of a castlegated  is a useful idea and I will keep up my sleeve. As you have done I would leave in the hands of a machinist if I go down this route

JB thank you. I had read previous posts by you on this and I am embarrassed to say I am trying 660 first despite your sensible advice about 635 and the proper tightening technique before finally deploying the lock tab washer. She's loosened before on the RLeft but this is the first time that any sort of glue has been used....so there maybe damage that will mean my efforts are in vain anyway. If she fails again I will use new parts and your technique along with 635

Gideon that is a great link...I am excited to call them to discover the price. I will post a price once I have. I am afraid your link to RichardH's  analysis does seem to let me see anything....I'll do a RH search on this forum and see if anything comes up.

Thank you all. I'll let you know how my current attempt has gone.

If you haven't yet read the analysis by Richard H on this problem, then do read it before you do anything else about this

https://groups.io/g/LotusEuropa/files/Stress%20analysis%20of%20Europa%20rear%20axle.pdf

I have seen that analysis before but never took the time to read it but your suggestion prodded me to finally read it. Very interesting. While I certainly don’t dispute his analysis, I have always understood that changes in the TC/TCS improved the situation (rather than make it worse). I certainly haven’t done a study on TC stub axle or bearing failure like the author did so I could be ignorant of the situation but I have heard of very few failures on TCS. Maybe somebody can update me.

Our own andy harwood started investigating using VW stub axles and CV joints. The stub axles are hardened and there is large assortment of axle lengths. It seems like a very good “final” solution that doesn’t seem to require a whole lot of development.

Hi All just had a very nice conversation with Peter at PA Motorsport. He uses these for his single seaters. He knows they fit series 1 Europas but is unsure of later versions. I think he said they were Imp outboard driveshaft. So do the series 1's fit series 2's.? They are 295 for each one and 24 for each nut....didn't ask if that was plus vat taxes etc...that's £

I said i would send him any engineering drawings I could get my hands on to show the series 2 dimensions etc...i'll go digging when I get home unless someone has a pdf of these dimensions we could rely on.

S1 and S2 take the same rear stub-axle.

That PA axle looks to be the perfect, bolt-on fix.  Combined with hardened spacers and you should be good.

OK, forgot to mention another source of "hub nut loosening".  That is a soft lock-tab washers.  Most of the washer you can get are "soft" steel so you can fold it over.  Well, soft works both ways and it can "thin" out under pressure "loosening" the hub.  A proper lock tab washer will be hardened steel with a foldable tab spot welded to it.