5 Speed Transmission

Model As were designed for an era of 50 MPH roads.  Today they rev too fast at 60-65 MPH.

The table at the right shows how fast a Model A with a 3.78 Rear End goes in each gear at 2000 RPM.  

45 MPH is too slow.

The Speedster needs to do 60 @ 2000rpm

Here are the choices :
       - Put an Overdrive in the Torque Tube-- a Mitchell is about $2000
       - Lightened and Balanced Engine to Rev Faster -- about $3000
       - Higher Rear End Ratio -- about $500
       - Newer Transmission with an overdrive gear -- $500-2000

I chose to go with the newer transmission... specifically a Borg Warner T5 5 speed transmission out of a Chev S10 pickup. I liked the closer gear ratios, synchromesh,  62mph at 2000 rpm, and lower cost.

A good junk yard  transmission was $200.  35,000 miles, clean oil. Took a day to find.  Be sure you get the shift lever, knob, leather boot, boot retaining rings, rubber mount for rear (GM 15661170), plug for reverse sensor, plug for speedometer, and driveshaft with u joints and splined shaft.

The front shafts are either 14 or 26 tooth splines.  I got a 14 tooth spline. Stock model A clutches are 9" diameter. 

You can buy a kit or assemble the parts yourself.  The key parts are
     an Adapter Plate ($90)
     a Sleeve  for the Throw Out Bearing  ($35)
     a Pilot Bearing Adapter  ($20)
     a Clutch Plate with the Spline mounted 1.5" aft of the clutch disk.

I bought this stuff from one of the kit guys (Auto Restorations 800-955-3193)

The Driveline Page explains how I solved the Open Drive Line problems.

The rest was simple fabrication.

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