WhenThree Plus Four Became Five!
........or, How I Learned the New Math!

 

This is the story of how three long days of work converted the four speed gearbox in my E-Type into a modern five speed! The story begins in the summer of 2003. My wife and I enjoy attending the JANE Show in Sturbridge, MA. That summer we decided to make the trip from our home near Syracuse, NY to Sturbridge in our 1965 E-Type FHC. The fastest route for the 250 mile trip is over the NYS Thruway and the Massachusetts Turnpike. Of course, that involves keeping up with modern highway traffic, which tend to be in

the 70 - 75 mph range in spite of the legal 65 mph limit. I was chagrined to realize that at 3000 rpm I was doing less than 70 mph! So here I was driving a 150 mph car with an axle ratio so low that I couldn't keep up with modern traffic without the engine screaming its head off! And we all know the reason. When Jaguar exported the E-Type to America in 1965 they were competing with Corvettes with their huge V8's.....and they knew that all Americans love acceleration. So E-Types destined for America were equipped with a 3.54 axle ratio instead of the 3.07 used in European models. It was clear that something had to be done. Either I had to change the axle to the European 3.07 and lose some of the low end torque, or convert to a modern five speed gearbox with an appropriate overdrive ratio in fifth gear. I chose the latter.

Once I had determined that this was a project I was going to take on there were many important decisions to be made. Which gearbox? What ratios? Could I do it in my own workshop? I had heard that there were bolt-in kits available that could be handled by an amateur hobbyist like myself. And I had removed and replaced the engine and gearbox a few years ago during the restoration of the car.....so why couldn't I do it again?.....only this time with a new bell housing and gearbox? Piece of cake! But since this would be a major project I began a campaign of gathering as much information as I could from those who had actually made the switch. I gradually homed in on the choice of gearbox that would be best for me.....the T5 with "close ratio" lower gears (2.95:1 first) and 0.73:1 fifth gear. And based on some of the comments that I received I was beginning to have some doubts about my ability to do the project within the limited capabilities of my home workshop.....but I was determined to press ahead anyway!

By early 2004 the project was only in the talking stage, but I knew that if I was going to get it done that summer it was time for some action! Although my home Jaguar club is in Central New York, I also belong to the Sun Coast Jaguar Club in the Tampa area, since we winter there. My big break in the project came at a SCJC meeting in February. My good friend, Gary Hagopian, was there. In discussing the project he made the comment (in a weak moment under the influence!): "Hey, why not just bring the car to my shop in New Hampshire and we'll get the job done in three days?" Needless to say, I jumped at the offer.....yes! That settled my concerns about getting it done in my limited workshop. Also in on the discussion of the project were Larry Ligas and Dave Hinton of Predator Performance. They suggested the T5 kit manufactured by Medatronics Corp. in Tequesta, FL. Soon I had ordered the kit and arranged to have it shipped to Gary's winter residence in Weeki Wachee, FL so that he could bring it north in his trailer to his shop in NH. So now the die was cast....no backing out of the project now!