TECHNICAL BULLETIN TB-12-04

 

January 16, 2012

Effective Immediately

 

Stafford Motor Speedway has made the following additions/changes to its SK Modified® rulebook effective immediately.

 

20E- 10.4 TRANSMISSION -

A. Only OEM production stock 3 & 4 speed transmissions with OEM production gear ratios  or Richmond 2-speed transmissions as produced by Richmond. Modification of the dog-ring and slider only of high gear only, in Richmond 2-speed transmissions is permitted. No other modifications of any kind are permitted. The 2-speed Richmond transmission is the ONLY aftermarket transmission allowed. The following Richmond 2-speed transmission part numbers are the only approved part numbers: 7020010X, 7020026X, 7027010X, 7027026X, the X representing Richmond’s ratios letter designator. The following Richmond produced gear ratios are the only approved ratio for use in the Richmond 2-speed transmission: 1.2250, 1.3391, 1.4588, 1.5956, 1.7442. Top loader transmissions are not permitted.

B. OEM Stock cast iron, aluminum or magnesium transmission housings, or the Magnus part number MRPSA-1009 housing are permitted. The OEM Stock transmission side covers must be used.

C. Only OEM type, steel, angle cut forward gears are permitted in non-Richmond 2-speed transmissions. Square cut forward gears are not permitted, except in the Richmond 2-speed transmissions

D. Removal of first gear, or replacement of first gear with a metal spacer, in 4-speed transmissions is permitted. All other forward and reverse gears must be in working order, and they must be operational from inside the driver’s compartment. All transmissions must have a constant engagement of the input shaft with gear and countershaft with cluster gears.

E. Five-speed transmission, with gears removed is not permitted.

F. Quick change transmissions is not permitted.

G. Automatic or semi-automatic transmissions is not permitted.

H. Machining or lightening of any internal rotating or non-rotating parts including gears, shafts and case are not permitted. Gun drilled transmission shafts are not permitted. Welding on any internal part will not be permitted.

I. Additional or different from OEM bearings other than the tail-shaft, which may have roller bearings, are not permitted.

J. Auxiliary, over or under drive transmissions are not permitted. High gear must have a ratio of 1 to 1 and no other gear may have a ratio higher than 1.20 to 1.

 

                   

Cc:

Tom Fox

Jay Shea

Chuck Zentarski

Mark Arute