Slotted Nut Size for S4 Front Hub?

[jbeach]

Dear Front Hub Experts (again):

I'm ready to put the nuts onto the newly-rebuilt front hubs for my '69 S4 DHC and properly adjust. Unfortunately, I have misplaced one of the slotted (some say castellated) nuts that goes on the end of the axle. My wheels are the knock-on (Nader Nut) type.

I've checked the local Fastenal and they've provided slotted nuts with the proper 1/2 x 20 fine thread pattern. But while the "wrench-size" of the nuts that came off is 13/16", the only size Fastenal has is 3/4". Here is my old one next to the one from Fastenal:

It seems to me this nut bears very little stress and I'd much rather finish this project today than having to wait for yet another package from RDent or Dave Bean (both of whom have already been life-savers on several occasions). But I'll wait if the consensus is i need the 13/16" for safety or other reasons.

On a related note, I've plowed through my Workshop manual to find a section listing the standard fastener sizes for use on the Elan, but can't seem to find it. I'd swear I've seen it before in the Manual, but am at a loss to remember where. Advice?

Thanks in advance,

John

[CBUEB1771]

I would not be at all concerned about using the nuts from Fastenal. Slotted and castellated nuts are not the same. Castellated nuts have more height, in fact too much height to be used on the front hubs of an Elan. If you fully tighten a castellated nut on the front axle of an Elan the slots for the cotter pin will still be "above" the corresponding hole in the axle. Also, fastener data are found in the Service Parts List, not the Workshop Manual.

[jbeach]

Thanks Russ, very helpful.

I'm still unclear where to find fastener sizes. You say Service Parts List. I don't have that document, but Ray provides access to the Lotus Parts Manual at http://www.rdent.com. Is that the same thing?

To me the obvious place to list the size of a nut or bolt would be where the part is listed in the Parts Manual. But, as you can see, the Parts Manual entry for this slotted nut only has a parts number. No size.

I've looked elsewhere in the Parts Manual but to no avail. How am I so dim?

John

[CBUEB1771]

John,
The fasteners are shown throughout the Service Parts List in accordance with where they are physically located in the car. The Introduction section includes a table showing how to decode many of the fastener part numbers into common parlance such as bolt with hex head, diameter and length in sixteenths of an inch and thread, fine or coarse. However not all fasteners have a decodable part number. For example, nearly all of the fasteners associated with the engine block are listed by their original Ford of England part number. The slotted nut for the front axle is an odd case because it is an otherwise standard 1/2-20 slotted hex nut, why it was given a Lotus unique part number is a mystery to me. The online Service Parts Lists at Ray's site are frustrating in that the fastener part number decoding table lost its formatting and so it is very difficult to read.
Russ