The MGA With An Attitude
Converting DISC WHEELS to WIRE WHEELS or vice versa - FS-301

At 11:49 PM 3/16/05 -0700, Steven Freeman wrote:
"I recently got a great deal on chrome wire wheels for the car, which I always wanted. I was hoping that you could take me through the steps of the change over."

It all starts with such innocence. I did this once when I was in college, at a time when I was in possession of two MGA, one with disc wheels and one with wire wheels. There are no adapters required. Simply exchange the original equipment parts that are different between disc and wire wheel cars. Consult the Moss Motors MGA parts catalog for reference to which parts are different.

The front is easy; just install the appropriate splined hubs and knockoffs. The spindles, wheel bearings, brake rotors, calipers, caliper mounting plates and hose fittings are all the same for the 1600. For the 1500 the front hubs and brake drums are different for wire wheels. For two 1500 cars it is a direct swap. For two 1600 cars it is a direct swap. To swap WW and DW parts between one 1500 and one 1600 car you would need to source the exchange front hubs for both cars, plus different front brake drums for the 1500.

For the rear you need to change the entire real axle assembly. The halfshafts and axle housings are 7/8 inch shorter on each side for the wire wheel set up, where the splined hubs make up the difference in length to maintain the same track width. Shock absorbers, leaf springs, leaf spring mounts and flexible brake hose is the same. All of the brake parts on the axle are the same. Even the two steel brake pipes on the live axle are the same part number, just formed a little different. You will need to change the hand brake cable.

I have seen people bolt TR6 rear splined hubs onto the MGA disc wheel rear axle, but that puts the wheels and tires outward about an inch where they may interfere with the fenders (especially if you want wider tires). There are available "conversion halfshafts" to change a DW rear axle to WW, but these shafts are again 7/8 inch longer and will set the rear wheels wider similar to bolt-on splined hubs. I am pretty sure there is no conversion halfshaft to change a WW rear axle to DW, as that would reduce track width about an inch on each side.

There are occasionally people looking to change from wire wheels to bolt on wheels. If I had a wire wheel car I would make this swap to bolt on wheels. There is a much better variety of wheels available for bolt on application, which is generally important for competition vehicles. If you can get the two cars together for a day or two it is fairly easy to swap parts between two cars, and you might work out a good deal on the price, like even up swap for the parts. You might post inquiry for a swap partner to the mgs e-mail list or one of the MGA bbs. The parts also pop up on e-bay fairly often.

Buying the required parts as new replacement parts can be somewhat expensive, but if you were so inclined, here is a reference list of parts to convert a 1500 car from DW to WW, without changing the rear axle housing. Prices change with time and place, so you can fill in the last two columns if interested.

Item Quantity Description Part Number Price/ea Total
1 5 Wire wheels WWP452    
2 2 MG RH spinners AHH7317A    
3 2 MG LH spinners AHH7318A    
4 1 Hub Fr RH ATB4180    
5 1 Hub Fr LH ATB4181    
6 1 Hub Rr RH ATB7204    
7 1 Hub Rr LH ATB7205    
8 8 HT nut 7/16" FNZ507    
9 4 L/tab W/W B/drum ATB7209    
106 Locktab ATB4125    
112 Gasket, flange GFG111    
122 Seal Rr GHS211    
132 O-ring seal ATB7354    
142 Seal Fr hub ACF4004    
152 Brake drum FR 1500 WW ATB4165    
162 Conversion halfshafts KO184/10    
172 Core Plug 1 5/16 dish 2K8160    

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