<VV> Fwd: S10 wheel lug nuts

Bryan Blackwell bryan at skiblack.com
Mon May 4 13:30:24 EDT 2020

Hi folks,

One of the folks in Central Virginia Corvair Club, David Robertson, has a late with a set of alloy S-10 wheels.  I wrote and asked if he could tell me what he'd done and if I could post to VV, here's his reply:

> Begin forwarded message:
> From: david robertson <corvairdave at msn.com>
> Subject: Re: S10 wheel lug nuts
> Date: April 30, 2020 at 1:57:57 AM EDT
> To: Bryan Blackwell <bryan at skiblack.com>
> The 5-spoke LS 'swirly mag' wheel center cap is held on by plastic lug nut covers.  I think these rims were first offered in '96.  Most had dark grey accents, but there were a few with gold accents (I think these came on special edition 2WD S-10 Blazers).  
> The plastic lug nut covers screw onto special lug nuts with external threads designed just for them.  GM used variations of this external threaded nut with plastic cover on many of their cars and trucks with alloy rims.  Probably because the plastic cap won't rust and no extra fasteners are needed to retain the center cap.  A regular bulge seat nut will hold the rim on, but there is nothing to retain the center cap.  OK for autocross or racing, but looks 'incomplete' on a street car.  
> The larger Extreme package rims probably use the same lugs, but I don't have any experience with them.      
> The other common 'second generation' S-10 rim is from '95 and earlier (I believe).  It also has 5 spokes, but is of a simpler design and uses a black or chrome plastic center cap.  These use the special lugs and covers, too.  
> Some GMC S-15 and Sonoma use the same system, but they look too 'truckish' for a Corvair IMHO.  
> GM started changing to metric lugs in '81.  Hence, all S-10, S-15, and '82 on Camaros and Firebirds use 12 mm x 1.5 lugs.  Therefore you CANNOT use the lugs from the donor vehicle on your Vair.  Fortunately, the aftermarket figured out a long time ago that we scroungers would want to put these rims on older GM products with 7/16" studs and made a special 'conversion' nut identical to OE, but with 7/16" internal threads.  The first ones I bought back in 2003 came from Prestige wheel.  I think they're still around.  Dorman also makes them: part number 611-160 is usually sold in boxes of ten.  They also make a plastic lug nut cover: part number 611-615, also in boxes of ten.  The covers are not as nice as GM covers.  If you have decent GM covers, I'd stick with them.  The Dorman products are pretty reasonable from Rock Auto.  Some other on-line parts dealers are probably competitive.  FLAPS  (chain stores) are usually much higher, unless you 'know somebody' or have a commercial account.  
> BE AWARE, while the earlier rims go on with no problem, in '96 GM changed to a metric hub size.  The center hole in the rim is a little too small for the Vair (and most older GM cars).  To keep the rim 'hub-centric' and centered, the center bore should be machined properly.  Russell Davis took care of mine years ago, but I assume some people just file or grind the center hole until it will fit over the hub.  Of course, then only the studs are supporting the rim.  I suppose you could also get the car's hubs turned down on a brake lathe or a good size shop lathe.  The fronts wouldn't be too bad, but the rears would require hub/bearing disassembly.  
> WARNING, the factory studs on the rear of late models vairs are extremely short.  All replacement studs are made to match the longer factory front studs.  Put new studs on the rear.  Rob some OE fronts from your junk collection if your budget is really tight.  Alloy rim centers are much thicker than the stock steel rim centers.  The short studs will not allow enough thread engagement to be safe.  
> David    

More information about the VirtualVairs mailing list