VW Type 2 Fuchs wheel conversion
by Harold Williams
July 2011
When I decided to switch to Fuchs wheels I wanted to retain my
current disk brake set up. I used a 912 hub which is 1/2" narrower
than a 911 hub. This would allow a wider wheel/tire combination. I
also used a 912 front rotor due to the dimensions being very close
to the stock '71 VW disk. This allows the use of the stock VW
caliper or Wilwood caliper using the stock mounting location, with
the option of changing to a bigger rotor/caliper combination. The
912 disk didn't require any modifications to work with the Wilwood
caliper I'm currently using. The disk may need to be turned down to
work with the VW caliper. The V.W. rotor is approximately 10.750" vs
the 912 rotor at 11.125".
I test fit a few different wheel/tire combinations. The widest was a
Fuchs 3 pc. wheel measuring 8" x 17" w/245/35/17 tires. The
backspacing is 5.5". This combination fits in the front wheel well
with a slight rubbing on the inside if the wheel is turned full lock.
At this time I'm going back and forth between Fuchs 7" x 16"
w/205/50/16's Toyo T1R tires and Fuchs 7" x 15" w/215/55/15
Michelin TB15 tires.
Front hub
Below is a description of the modifications made to the 912 hub. An
aluminum spacer was made to fit between the hub and disk to locate
the disk in the stock V.W. disk location. This allows the use of
the stock caliper, or a Wilwood caliper, which is pretty much a
direct swap out. The dimensions below worked for my application, they
should be considered a starting point.
Hub modifications: The inner & outer bearings needed to be moved out
to compensate for the bus spindle being longer than the 911 spindle. I
made 2 spacers that were inserted between the bearing seat and
bearing. The front spacer is .225" thick, 1.625" i.d. and
1.780 o.d. The rear spacer is .200" thick, 2.050" i.d. and 2.310"
o.d. These were a snug fit, but not a press fit. The rear of the hub
was also enlarged to 2.560" to accept a stock VW bus bearing seal.
The rotor mounting surface was flycut.
Spacer: 1.250" overall thickness. Recess to fit the hub, .225" deep x
4.210" i.d. Extension to fit disk, .265" high x 4.220" o.d. Spacer
thickness .950". Drill 5- 8.5mm holes for bolts. Allen head bolts
measuring 8mm x 50mm with 2 washers and lock nuts were used.
Front hub parts
Parts list
Prices (paid in 2009)
Porsche 912 front hubs (used)
$70.00 pr.
Porsche Inner wheel bearings
17.00 pr.
Porsche outer wheel bearings
13.50 pr.
VW rear seal
912 solid rotor (.050" thick)
100.00 pr.
dusk caps milled from billet aluminum
20.00 pr.
1 1/2" x 6" aluminum spacers to relocate rotor
100.00 pr.
Rear hub seal to try: SKF-38/62/10 HMSA7V
For the rear I'm currently using a H&R 5/8" thick 112mm to 130mm
wheel adapter. Wheels and tires are Fuchs 3 pc 8" x 17"
w/245/35/17's. The backspacing is 5.5". I rolled the rear fender
using a baseball bat to clear the tire. A Fuchs 8" x 16" from a '86
944 turbo (1 yr. only) would also work. This wheel has an approximate
backspacing of 5.5" vs. a 911 8" x 16" which has a 4 7/8" back
spacing. I'm in the process of trying a few different things to avoid
using the wheel adapter, as well as fitting a wider wheel/tire
combination.
VW rear hub modification
by Harold Williams
August 2011
In order to avoid using a wheel adapter, which i had been up to
this point,
I decided to modify the stock VW 5 x 112mm rear hub of my
1968 Crewcab to the Porsche
5x130mm bolt pattern. For some reason the hub has a "V" notch. To
fill it, I cut a 1/8" wide x 3/16" deep groove in the notch. A piece
of 1/8" thick steel was inserted into the notch and welded on both
sides. The holes for the drum retaining screws were also welded. I
used a 5x112mm to 5x130mm wheel adapter bolted to the hub to locate
the Porsche bolt pattern. The holes are 14mm to accept either Porsche
or after market studs. The old studs were cut flush and left in
place. To give the wheel some extra support I made a hub centric
ring 2.815" o.d. dia. x .500" high and welded it to the hub. The
ring was slightly larger than the final dimension, then turned it
down to the finish size after it was welded. The hub was turned
down to a 6.195" o.d. diameter to fit inside the rotor.
I used 77mm studs to allow the use of a spacer if
needed. To compensate for the longer studs I drilled out the end of
the Porsche aluminum lug nuts.
Since I planned on retaining the Wilwood calipers from the first
disk
brake conversion I chose a Boxster rotor (#986-352-401-04-MS)
which is
dimensionally close to the Audi rotor I was using with
that set up.
The o.d.diameter was turned down from
11.640" (291mm) to 11.125" to enable the caliper to clear the bolts
on the 3 pc. wheels I was using. This probably wouldn't be necessary
using 17" diameter wheels. The inside of the rotor was rubbing the
trailing arm so a 1/16" aluminum spacer was used between the hub and
rotor for clearance. The caliper bracket was made from 3/16" thick
aluminum plate similar to the previous one. The "S" shape on the top
section of the bracket allows the caliper to set into the bracket.
To fit the fatest tire in the wheel well, heavy duty spring plates
replaced the Sway-a-way adjustable spring plates. The wheels are set
up with 1 degree negative camber and 0 toe. I stretched/flared the
fenders approximately 5/8" using a 1 1/2" diameter aluminum pipe.
There is about 1/8" clearance between the inside of the fender and
the tire side wall. The current wheels are 3pc Fuchs centers with
16" BBS 5.5 inner and 3.0 outer rims making the rim 8.5" wide. Tires
are Toyo T1R 245/45/16's measuring 9" wide at the side wall.
The rotor-face-to-rotor-face distance is approximately 55 9/16" vs 58
3/4" using the '86 aluminum 944 trailing arms. A stock '86 944 turbo
8x16" Fuchs wheel (one year only) should clear the fender. The 944
8" x 16" has approximately 5.5" of back spacing vs 4 7/8" back
spacing of a 911 8" x 16" Fuchs wheel. A 225 or 245/45/16" should
also work.