I'm looking for comments on mounting aluminum wheels designed for 740 hubs (designed for 12mm studs) onto 240 hubs (which have 1/2" studs). Some suggest that the 1/2" conical lug nuts don't seat deep enough into the conical depressions of the 740 wheels that were intended for 12mm lug nuts.

Has anyone installed 740 aluminum wheels on a 240 using standard 1/2" lug nuts without having problems? Specifically, I'm intending to mount Draco rims on my 240.

I've been told that the same problem does not exist when installing 740 steel wheels on a 240, because the conical depression in the 740 steel wheels is wider than on the aluminum wheels.


This relates to another post I did on Monday "Virgo vs. Draco wheels - which Volvos do they fit? 𖑀]". That post clarified which rims fit which cars (240/740/940) in regards to caliper clearance, etc. I just need to know if the lug nut discrepancy is a serious issue.

The Draco wheels require a short, straight shank lug nut for proper (SAFE) installation. While I'm sure you could mount them with a hardware-store hex nut, that doesn't mean that's a good thing to do. The Draco wheels as supplied for the 700 cars came with the "conical seat, short shank" nut with a metric thread. The conical seat lug nut for the 240 wheels (steel and Coronas) does not have the 0.300" long shank which engages the bolt holes in the Dracos. I took close measurements from the metric nuts supplied with my new Dracos, and got the same thing with the proper SAE thread for my 240.

Steel wheels off a 700 can use the regular nuts on the 240.

For me, having spent $300+ for wheels and a similar amount for good tires, dropping another $30 for the proper wheel nuts was a no-brainer.

Go to http://www.prestigewheel.com/Image5392.asp to see the nuts.

Thanks for pointing out the appropriate part. From the other post, I too was thinking: stud change?

I had the tires mounted today, and was hoping to find the lug nuts locally (Toronto), but I'll have to settle for mail order, and put them on the car next week. Prestige gave me the name of their Canadian distributor, who put me in touch with www.tiretrends.com in British Columbia.

I couldn't believe how difficult it was to try and find another source. How did you come by Prestige, and the correct specs? Did you have the specs for the standard 740 metric nut?

I had the new metric nuts, and as I work in in engineering lab, I just took external dimensions and measured the thread. Finding a supplier just took some time searching on the web.

Well, everything about the short shank nuts you're suggesting made a lot of sense - I sat a standard nut in the Draco wheel, and indeed, it doesn't seem to seat in very deep. Anyway, I tried to order them, and found that they wouldn't ship until Monday. From across the country, I might not even get them next week.

Out of curiousity, I went to a Volvo dealer to have a look at the factory nuts for the Draco. The guy pulled up the diagram for a '92 740, which showed a Draco, and then pulled the nut. It's a standard shaped nut! You can't tell the dimensional difference between it an a 240 nut I bought from FCP Groton (other than the fact that the threads are different).

The guy there said that no Volvo had a lug nut with a shank until one of the FWD series. He figured that if you got shanked nuts with the Dracos, that they were aftermarket.

"The Draco wheels as supplied for the 700 cars came with the "conical seat, short shank" nut with a metric thread. The conical seat lug nut for the 240 wheels (steel and Coronas) does not have the 0.300" long shank which engages the bolt holes in the Dracos. I took close measurements from the metric nuts supplied with my new Dracos, and got the same thing with the proper SAE thread for my 240."

Smitty--

Does this mean that to put Dracos on a 240 series you have to replace the studs? Lot of work and $. Is there any SAE lug nut that will seat properly on the Draco rim?

Doug Harvey

Hell, no... waaaaay too much work to replace the studs. I just bought the correct lug nuts (short shank, conical seat, 1/2-20 thread) from the source I mentioned (the link) in the previous post. With shipping I think I paid about $30.

Smitty--

Sorry I didn't understand from your first post that the proper SAE nuts could be had.

This means Dracos can go back into my search pattern.

Doug Harvey

Doug, you can get an oblique view of the Dracos on my 245 ("SOG" - Son O' Gutz) in the Gallery. Narrow the search to 200 series, and my shot atop SOuth Mountain is about a dozen pictures in on the first page. I do like them !

Actually, it's white... the late-day sun makes him look gold in the pic. Modified the roof rack so there are just the 2 longitudinal bars, no cross bars.

No issue at all. Use any 740 wheels on a 240, using any 1/2"-20 lug nut.