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!

Since Gary was kind enough to offer his help I wanted to do it on a schedule that was best for him. That turned out to be the three days following the annual JANE show in late July. But since we wanted to get the job done in three days there was an obvious long pole in the tent...the need for a new driveshaft since the T5 is longer than the Jaguar gearbox. The turnaround for fabrication of a driveshaft is two days. We solved that problem by measuring my car so that Gary could have the driveshaft ready when we started the project. I made the measurement by dropping plumb lines to the garage floor at the front of the bell housing and the forward edge of the input flange of the rear end, and measuring the distance between. Then Gary made the necessary subtraction of the new gearbox/bell housing and the required output flange/ rear seal clearance from my measurement to get the proper driveshaft length. With the driveshaft made and the Medatronics T5 kit in Gary's shop we were ready for the fun to begin! So on Sunday, August 1st after the JANE show, I followed Gary and Sue to their summer home in Sunapee, NH in the E-Type while my wife, Carolyn, rode back to NY with another JACNY member. After getting settled in their downstairs guest room, and relaxing with a cool one on their deck it was time to get to work!

At 6 PM on Sunday evening Gary and I retired to his shop to begin the project. But first a word about the Medatronics kit. Although I had purchased it back in March, it was the first time I had actually seen it. It's a complete kit including everything needed to make the installation, except the driveshaft. Besides the gearbox itself, it included a new bell housing, clutch disc, rear mount, and Jaguar style shifter and knob. I was pleased with what I saw, and it seemed to me that we had everything in hand to make the switch an easy one....but as it turned out, that wasn't quite the case!

We got right to work. The first step was to get the car up in the air on jack stands front and rear....under the forward pivot of the lower wishbone in front and between the shock and the wishbone in the rear. And they were high jackstands, probably a couple of feet, so the car was well up in the air allowing plenty of room for the underside work. And that turned out to be Gary's job. He did the heavy work underneath while I was assigned the relatively lighter work topside. We elected to remove the engine and transmission from the underside of the car. So that meant stripping the engine so that we could drop it down to the floor. And we wanted to accomplish that with minimum disassembly of the car. We didn't remove the bonnet, simply removed the hinge pin and tipped it forward so that it rested of its own weight on a chair that Gary had in the shop for that purpose. The interior of the car was left intact. We just removed the gearshift ball so the shift lever could drop down through the boot. Everything forward of the engine, including the header tank, was left in place. In tackling my topside work, I assumed that the carbs would have to be removed to get at the lower intake manifold nuts. I had only started to do so when I got a loud "Whoa!" from Gary. He pointed out that with the distributer removed it's possible to get your arm below the carbs to get to the nuts. I had my doubts, but after acting like a contortionist and getting a lot of scrapes and bruises, I was able to get the carbs and manifold off as a unit.

One of Gary's more difficult jobs underneath the car was the removal of the torsion bar reaction plate. That meant relaxing the torsion bars by removal of the upper wishbones, disconnecting the shocks, and disconnecting the upper ball joints. With that accomplished, and with the engine stripped, we were ready to drop it to the floor. That was done with a chain falls that Gary has suspended from a heavy beam in an opening in the ceiling of his shop. So down it went onto the floor....and it was still only Sunday night! It looked like we were well on our way to beating our planned three day schedule. But tomorrow was to prove to be a day in which that schedule would be put in serious jeopardy!

On Monday morning, after a great breakfast prepared by Sue, we retired to the shop all fired up to get the job done in record time. The next step was to get the front of the car raised high enough to maneuver the engine out . That was easily accomplished using the chain falls with heavy straps under the upper frame members. Using wooden dowels we rolled the engine out, and separated the bell housing from the engine. It was only Monday morning and we had reached the down side of the curve....ready to start the re-assembly process. But there was trouble ahead! When we attempted to fit the new bell housing to the nose of the gearbox it didn't fit! The opening in the bell housing was .003" too small! Since Gary has a milling machine in his workshop that was only a minor problem. He enlarged the bell housing opening by .005", and then it fit the transmission beautifully. But with that problem solved, we found we faced a bigger one. On removing the clutch disc we found that it was 10", and I had ordered a 9.5" one! We called Paul Cangialosi at Medatronics hoping that he could get us a 10" one overnight. But he didn't have any!...... though he had some on order from his supplier. Paul was good enough to put us in touch with the supplier, who agreed to divert one to us by UPS Air Overnight. So it looked like the quick and accommodating action by Paul and his supplier would save our schedule....but only tomorrow would tell for sure. Though this was a setback it wasn't a disaster. The rest of the day Monday was spent fitting the transmission to the tunnel. We raised the transmission into place to locate areas where there would be interference. The T5 is a tight fit in the 4.2 transmission tunnel. Gary ground off the upper forward corners of the T5 case. Inside the tunnel he ground off some ends of screws holding the tunnel cover in place, and, using a ballpeen hammer, created a small bulge in the side of the tunnel where the back-up light switch would be located to preclude any shorting. By Monday night we were ready to put the car back together....if we only had a clutch disc!

The UPS truck pulled into Gary's driveway at 10:30 AM Tuesday morning with a 10" clutch disc for us. We were two happy campers! From there on the re-assembly went smoothly. However, after we had re-assembled the transmission to the engine we noticed that the clutch release arm hit the forward edge of the transmission case opening. Gary ground off the case to get adequate clutch throw. We put in lots of hard work....but by 6PM Wednesday night the car was all back together and ready to go. Now it was time for the acid test....the first test drive. I'd like to say that all was perfect, but it wasn't quite. When we drove out of the driveway we heard a loud clanking! Oh, oh....what's the matter? It turned out that the u-joint is very close to the forward hand brake bracket. When making a right turn the engine shifts very slightly to the left....just enough for the u-joint to hit the bracket. But if I drove carefully, it wouldn't be a problem on my trip back to Syracuse. I would have to tackle that problem when I got home. We loaded all my original parts in the back of the car, and I was ready for the trip home.

After a good night's sleep and another fine breakfast I said good-bye to my gracious hosts and headed for NY. I made the trip without incident, and was happy to see about a 700 rpm drop on the tach. Now I had to address the hand brake bracket problem. After removing the transmission tunnel cover I could see where the u-joint was hitting the hand brake bracket. It turned out to be an easy fix. A friend who operates a body shop was able cut off a chunk of the bracket with a small air-driven reciprocating saw. Another small problem that I had to correct was that my car had the rubber shift boot with the small hole in shifter cover. The new shift lever hit the forward edge of the hole in the odd gears (1,3,5). The solution was the use of an old 3.8 shifter cover that Gary gave me. I had it re-trimmed with new covering and leather boot. And it even looks nicer than that ugly rubber boot!

There's a side effect to this installation that you might want to consider. The Jaguar's cast iron gearbox case absorbs gear noise much better than the T5's aluminum one. The result is that the T5 is noisier than the Jaguar transmission. I chose to use Dynamat from XK's Unlimited to alleviate this problem. I'm sure it's available from other suppliers. By heavily trimming it I was able to retain the original sponge rubber over the transmission. I molded a piece of Dynamat over the top of the transmission case just for good measure. Then using heavy paper to prepare patterns, I covered the outside to the transmission tunnel with several pieces of Dynamat. This has quieted the T5 gear noise considerably.

Now for some final thoughts on this adventure. Although the Medatronics T5 kit is a good kit it's not a simple bolt-in that can be easily handled by an amateur hobbyist. Don't attempt it unless you're prepared to address the problems I've described. If you do decide to do it yourself make sure you take action to get adequate clutch throw, and don't forget that handbrake bracket! And when the project's completed you'll love that fifth gear!