Posted: Oct 07 2006 at 10:05pm | IP Logged
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Flaminfrontier;
Here's an article I wrote that might answer a few questions.
WHEELS and Back Spacing... update 01.19.06
... Axles have two WMS (Wheel Mounting Surfaces) - as on the hubs. This does not set the ‘track-width’ of the vehicle. The mounting surface of the wheel can optionally be on the centerline of the tire (zero off-set) or on ether side of the centerline (positive or negative off-set). Most of us use the Back-Space method to determine tire clearance and fitment. As the BS measurement gets smaller the ‘track-width’ of the vehicle gets wider. Older Chevrolet and Wagoneer 4x4s had a BS of about 3.625 inches. Some of the modern 4x4s now have a BS of 5.5 inches. This was done to improve the scrub angle of the front tires. A very small amount of Back Spacing can shorten wheel-bearing life.
Note! Wide Tracking a truck via the BS method will shorten the wheel bearing life and may void some warrantees! But I've done it for short runs.
... To measure the BS lay the wheel with the outside facing down. Lay a straight edge across the tire mounting lip and measure down to the mounting surface. Don’t confuse Back Space with Off-Set.
... Zero off-set means the mounting surface of the wheel is on the center-line. A wheel can have a positive or negative ‘off-set’. Most people prefer to use the Back Space measurement. As the Backspace measurements become smaller the wheels will be farther outboard and the vehicle will have a wider track width.
... I have run many thousands of miles with my Full Size Jeep wheels (6 on 5.5 15x8 /BS 3.625) on several Nissan 4x4s. The center of the jeep hub and it is about 4.200 inches.
... The Nissan centering hole is 3.925 inches in diameter so the centering hole of Nissan wheels would have to be turned to the bigger diameter to fit the FSJs. Some of the Nissan wheels may not fit over or clear the brakes but some will as they have a variety of BSs and over all diameters. 1999 Frontier Se 4x4 wheels are 6 on 5.5-15x7 and 5.250 BS.
if the PIC does not show it can be seen at:
Or>>
http://www.fullsizejeeps.com/jeeps/files/1963-1983-Wagoneers /WheelDia3.jpg
Lug Nut Patterns
... The bolt pattern has two parts, the number of bolts and the the bolt circle diameter. The bolt circle is the circle which passes through the centerline of each of the hubs lugnuts. Wheels with 4, 6 or 8 bolt holes the measurement is simple: Measure from one hole center to the hole center directly across from it. Wheels with 5 bolt holes you measure from the center of one bolt hole to a line (or ruler) that is drawn between the opposite edge of the two opposing bolt holes. The bolt pattern is then indicated by the number of bolts times the bolt circle diameter - for example a 5x5" bolt pattern is 5 bolt hole arranged around a circle which is 5" in diameter. This may also be known as 5 on 5"
Special care must be used in selecting the correct lugnuts for many types of alloy wheels.
Have a good one and CUL.. Don S..
__________________ PLEASE >>> A SIG similar to mine can be VERY HELPFUL to all the members!
'99 4x4 3.3 Frontier Se KC Auto, 48,000 miles
'76 4x4 401 Wagoneer QT
'04 FWD 1.8 Sentra '08 FWD 2.4 Camry LE
Fort Worth
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