It's been three years since a bad transmission left us stranded in our 2+2 on a mountain top in Vermont. The JT5 I installed after that incident has proven to be an excellent modification. This year, I've embarked on a more ambitious project: to create a reproduction of the 1963 LeMans Lightweight E-Type. At first, I intended to install a Jaguar syncro box,  as was installed in the original car. But the gearbox was the weak spot that cost Jaguar the race, and ended any serious LeMans effort for many years thereafter. Subsequently, all the surviving Lightweights were recalled to the factory and refitted with ZF five speeds Aside from being incredibly expensive today, these ZF transmissions were no more successful that the original Jag four.  I recently had the opportunity to examine an original factory Lightweight...it had been converted to a Moss box, which says something about the original factory choices...reverting to the old box was considered an improvement!  So here it is, a car without a transmission, and no clear model to emulate. What follows is a summary of my latest research into transmission swaps.

      The question is different for a road car vs. a race car. On a road car, it is sometimes desirable to have a low rear axle ratio to give better off-line performance. This is why Jaguar fitted 3.54's to many US delivery cars. On the other hand, a low ratio rear limits top speed, so the cars so equipped had no shot at the magic 150 number. Furthermore, running a 3.54 means a fair amount of cabin noise at highway speeds, due to high rev levels. Finally, a low ratio hurts gas mileage.

      To drop the revs and gain back what's lost with a 3.54, two options are available: go to a higher axle ratio, or add an overdrive gear. Although more historically sensitive, higher axle ratios are not attractive, since off the line performance is still what counts here in the USA. A five speed (with an overdrive fifth) offers a way to get performance from takeoff to 150. It will also drop the revs at highway speed, giving a quiet ride and better gas mileage.  The question is how to do it without dramatically changing the nature of the car: in other words,  to add a fifth speed in a way that Sir William might have approved of.

 On a race car, the requirement is different. For high speed racing, the rear axle ratio is often very high....LeMans Jaguars had axle ratios at least as high as 3.07, in fact, the highest ratio in the "pit kit" was  2.64! This allowed the cars to achieve high top speeds...170+ was typical for the  LeMans E-Types.  But this limits performance from a dead stop, so an extra low first gear could be used to compensate. If the gear ranges were evenly spaced, then the driver would find that there wasn't enough gearing to cope with a challenging road course. One possible solution is to add an extra gear, but top gear would remain 1:1. This would allow the use of evenly spaced ratios, and provide a good selection for the driver. The ZF was such a close-ratio box. Note that close ratio doesn't imply that the top gear has to be 1:1, although overdrive close ratio boxes tend to be six speeds.  A disadvantage is that more gears add drag, reducing the effective output of the engine.

ZF. Just after the E was introduced, Jaguar ran a number of tests on a five speed ZF in the E. They concluded that it produced too much gear chatter for a refined sportster. But they used it in many of the well-known racers of the day, including the factory lightweights and low drag coupes.  The transmission proved to be a problem to the racers....it's very heavy, and places a lot of drag on the motor. There are some anecdotal reports of cracked engine blocks and bellhousings attributed to the stress involved with running the big ZF. (There's one point I'd like to make very clear: ZF was the ONLY five-speed factory fitted to  race cars during the E-Type era.)

 The ZF five speed was used in the factory Lightweights that ran at LeMans in 1963. It failed miserably, with two cars dropping out with transmission problems. One car crashed, and the fourth car barely completed the race, with first and second gear non operational.  LeMans was lost due as much to the lack of a good transmission as the superiority of  Ferrari.

 I tracked down a ZF when I was researching transmissions for my Lightweight. It's size and weight is truly astonishing...it took two strapping fellows to take it off the shelf. It looked to be more appropriate to a tractor than a race car. As to the price, well, if you have to ask, it's not for you. This transmission, rebuilt to perfection, will cost more than a good E-Type.

 Anyway, the ZF is nostalgia. There doesn't appear to be a modern ZF box appropriate to an E-Type.

Jaguar overdrive. It is possible to take the overdrive unit from a Mark X and bolt it up to the Jaguar 4, but this requires modification of the floor pan, which I was unwilling to do. For the Lightweight, an electric overdrive is simply not appropriate.

Getrag. In the early 80's, Jaguar offered Getrag 265's on V12 XJS's. These are excellent transmissions, well able to handle the torque of a V12. The Getrag 265 has a couple of weak points: certain boxes used friction synchros, essentially metallic cones with a high friction coating. Once the coating wears off, no more synchro. Layshaft bearings are frequent wear points. The box has a reputation of being difficult to service. Although there are a few 265's still available in the Jaguar community, the best place to go for one of these transmissions is a BMW specialist, where a rebuilt box can be had at a price competitive with other swaps.

 Some vendors are currently selling a Getrag 225 conversion for E-Types. This is NOT the same as the 265, and I have been unable to uncover reliable specifications or anecdotal experience. Conversion appears straightforward...an adapter plate at the front, and a shaft extension at the back.

 I once again emphasize that Jaguar NEVER used Getrags in XK-engined racers. In the 70's  a Leyland five speed was fitted to some non-export XJ6's, this was an unfortunate combination. And in the 1980's the Getrag 265 was fitted to XJS 12 cylinder cars. This latter combination was first done by TWR, and was very successful, but note that 265's are not offered as a standard kit by any Jaguar vendor.

Toyota. This was a tough one for me. When I did my original JT5 swap, my everyday car was an '88 Supra, with the perfect W58 transmission. Unfortunately, it was too nice to break.

 Let me back up a bit. The Toyota swap is facilitated by Jeff Dellow, in New South Wales. He makes conversion bell housings, which allow Toyota 5 speeds to bolt up to XK and V12 Jaguar engines. Knowing how good that Toyota shifter is, coupled with the low cost of the Dellow conversion kit, seemed to make this a natural choice. But the decision became difficult when I realized that Dellow built his kits for 'saloons' and XJS's. Using the most appropriate Toyota box with Dellow's "shifter forward" modification, the shifter would still be 2 inches too far back.

 If you consider the Toyota option, remember that the 'best' fit is the W58, which was used on 1987-1992 non-turbo Supras. It is a very limited production box, which may be another reason to think twice. The good news is that once you are set up for a W58, there are many other Toyota boxes, which could bolt up, if you can live with the gearing. I am told by a reliable source that the Toyota swap is only applicable to LWB E-Types, due to interference with the bodywork, hand brake, etc. I have yet to find someone who has actually done this swap.

 Bellhousings are now available from a second vendor, Conversion Components, in New Zealand.

Borg Warner T5 Worldclass. The BW T5WC is a high performance version of the familiar BW T5. It is used in many cars, including Camaros, Firebirds, and Mustangs, so parts availability is as good as it gets. Making this work involves modifying the bellhousing to accommodate the bolt pattern, and making sundry changes to shifter location, input shafts, and gearing. If you wanted a real cheap conversion, this could be the way to go, but be sure you have access to a machine shop and welding equipment. Also be sure to start with the correct transmission. This box comes in long tail and short tail versions, which differ in length by 7", and the shifter location varies by as much as ten inches! In some applications, the shifters are offset from the vertical, just to add to the complication.

 The torque rating on the BW T5WC is about 300ftlb, making them just adequate for the application. These boxes have a poor reputation in ultra high performance applications, as a result there are strengthened gear sets available.

 Borg Warner recently sold the tooling for the T5 to Tremec. It's uncertain whether Tremec intends to continue production.

JT5. The JT5 is the BW T5WC, with all the appropriate changes. The short tail version is used for SWB cars, while the long tail is available for V12's. Two gearing options are available. Gears are replaced by new Ford Motorsports high-nickel alloy gears, various modifications are made for reliability and fit. This is as close to a bolt-up as it gets..the shifter position is almost spot on to the original Jaguar 4!

  The short tail version does not have room for a speedometer gear, so it is equipped with an electronic sensor. In this case, your speedometer head will need to be converted to electronic as part of the swap. I am told that the workings fit in your old speedometer, and there is no visible change. If you can use the long tail version, no speedo mods are required. Note that the Series I and II 2+2's have a different floor pan arrangement than the Series III LWB cars, so be sure to check with the manufacturer to get the correct box.

 The JT5's are manufactured by Medatronics, Inc., it's available from most of the big Jaguar vendors. The manufacturer reports that the boxes are built up from new parts, which are expected to remain available despite Tremec's acquisition of the T5. When choosing a vendor,  be aware that the box is the same in all cases. However,  there are differences in the amount of preparation and set up done by the vendor, price, and the amount of customer service available. So shop around.

GTJaguar 6 speed. I never really considered this seriously. The GT Jaguar six speed is a close ratio transmission. Only sixth gear is overdrive. The box is built by Richmond Racing, and modified by GTJ for a good fit. Too expensive for me. This box is a difficult install, requiring modification of the center console.

Tremec 3550. This is a very high performance transmission originally meant to replace the BW T5 in racing applications. It is made in Mexico. When I did my original swap, I didn't research this extensively, since it was not widely available at the time. However, it's now a mainstream box in the Mustang community.  The effort of converting this box for Jaguar use is comparable to that required for the BW T5. It has a reputation of lacking smoothness. Personally, I think it's comparable to the Jag Synchro 4 as far as smoothness goes. I would suggest you try one yourself before you commit.

Waterloo TX51. The TX51 is a Tremec 3550, with the appropriate changes. Various modifications have been made to the case, input shafts, and shifter to allow bolt-up installation in an E-Type. A normal mechanical speedometer connection is provided. The TX51 is new in production. Several vendors have already signed up, so it should be widely available shortly. Be aware that the transmission is the same regardless of where it's purchased, choose your vendor based on preparation, set up, price, and customer service provided. It pays to shop.

Tremec/BW T56. This is a very high performance transmission, used in Dodge Vipers, among others. It is a six speed, and can be fitted out with various gear sets. The standard gear set is a double overdrive, which is really overkill.  It's a very heavy box, weighing in at over 100lbs. Unfortunately, there are no vendors currently doing swaps with this box: I have not been able to gather much information.

 A few years back I decided to install a five speed in my 2+2. At that time, I chose a JT5. The logic was simple...the 1-4 gearing was very similar to the Jag box, and having a .8 overdrive drops the revs very nicely when cruising. It was an off the shelf conversion, with good vendor support.

 The box proved to be smooth shifting and trouble free. Having lived with a JT5 for more than two seasons, I can report that I'm as happy with it now as when it was installed. Maybe happier, since I've forgotten how much it cost.

 When selecting a transmission for my Lightweight, I eventually dismissed the Jaguar 4 speed synchro, this box having failed so badly at LeMans. The ZF transmission, which the factory next installed,  can be had today only at great price, and was not well regarded in its day. At this point I had to evaluate exactly what I was planning to do with the car. Since it's really planned as a show & go, i.e., driven on the road and only "raced" for demo purposes, there really is no reason to restrict the choice. So I decided to go with a modern five speed. I gave some thought to a GTJ Richmond box, but the thought of modifying my aluminum floor pan was too much to bear. I then planned to go with a JT5, but there have been sporadic delivery problems with this transmission recently, I was unable to obtain one with a reliable time commitment. The vendor now reports that production will resume shortly. Given that I needed a transmission now, the TX51 has come along at the right time. I've driven a Tremec 3550 in a Mustang, and I find it to be perfectly adequate. Hopefully the Jaguar derivative will be even better.

                                                                                                  1           2       3         4           5         6
                                                        BW JT5 WC                  2.95       1.94   1.34    1.00      0.80      -
                                                        BW JT5 WC                  3.35       1.99   1.33    1.00      0.72      -
                                                        Toyota W58                   3.28       1.89    1.27    1.00     0.78       -
                                                        Toyota W55                   3.57       2.06    1.38    1.00     0.85       -
                                                        Toyota W57                   3.28       1.89    1.27    1.00     0.86       -
                                                        Toyota W59                   3.95       2.14    1.27    1.00     0.85       -
                                                        Tremec 3550  (TX51)     3.27       1.98    1.34   1.00      0.68       -
                                                        Tremec 3550 (TX51)      3.27       1.98    1.34   1.00      0.82       -
                                                        Tremec/BW T56             2.66       1.78    1.30   1.00      0.74    .50
                                                        Tremec/BW T56             2.97       2.07    1.43   1.00      0.80    .62
                                                        Tremec/BW T56             3.36       2.07    1.35   1.00      0.80    .62
                                                        Moss 4                          3.37       1.86    1.28   1.00      -         -
                                                        Jaguar 4 (Orig)                2.68       1.74    1.27   1.00**   -       -
                                                        Jaguar Syncro 4               2.94       1.90    1.39   1.00       -        -
                                                        Jaguar Syncro 4OD         2.94       1.90    1.39   1.00      0.80     -
                                                        Richmond 5                     3.27       2.13    1.57   1.23      1.00*   -
                                                        Richmond 6                     3.28       2.14    1.57   1.24      1.00    .76
                                                        ZF 5 Speed                     2.93       1.97    1.45   1.17     1.00*  -
                                                        Jaguar 4 (racing)              2.98       1.75    1.21   1.00+     -      -
                                                        Jaguar 5 (racing)              2.82       2.14    1.66   1.27     1.00*+  -
                                                        Getrag 225                      3.57       2.07    1.38   1.00       .76      -
                                                        Getrag 240/Sport            3.59       1.95    1.27   1.00       .73      -
                                                        Getrag 245/Sport            3.52       1.91    1.27   1.00 .      77      -
                                                        Getrag 260                      3.83       2.20    1.40   1.00       .81     -
                                                        Getrag 260/Sport            3.45       1.98    1.26   1.00       .73      -
                                                        Getrag 262/CR                3.71       2.40    1.76   1.26    1.00*   -
                                                        Getrag 265                      3.82       2.20    1.39   1.00      .81     -
                                                        Getrag 265/Sport            3.44       1.98    1.26    1.00      .73     -
                                                        Getrag 280                      3.51       2.08    1.35   1.00      .81     -

*These five's are close ratio, but not overdrive transmissions.
+Prototype transmission, never produced commercially
**First 100 Jaguar Syncro 4's
 
 

                                                                      Jag 4(SWB)              Richmond 5/6#                 BW-JT5(SWB)                Tremec/TX51
Front to end of tail                                          13.75"##                    21.57"                               15"**                            17
Front to transmission mount center     +             12.75"                       16.5/18                              14"                                15.8
Front to shifter center                                      12"                           *                                         11.75                            12.75
Front to end of input shaft                                 7"                              6.66                                   7"                                  7"
Pilot bushing diameter                                      .492                           unk                                        .492                             .492
Approximate Torque Rating (ftlb)                  300                              450                                   330                                400
Speedometer                                                Mech.                           Mech.                               Elec.***                        Either

***Short tail JT5. Long tail can accommodate mechanical drive
**Short tail JT5. Long tail is approximately 22" front to tail
*Richmond uses adjustable side linkage
#Unmodified
##LWB transmissions are 18" front to tail
 
 

        Sources for Borg-Warner T5 WC Transmission

           ABE Transmission and Gear Company
           Outside CA (800) 821-0308
           Inside CA (800)631-8756
           http://www.abetrans.com/

           Any Chevy Dealer (Camaro applications)
           Any GMC Dealer (light truck applications)
           Any Pontiac Dealer (Firebird applications)
           Any Ford Dealer (Mustang applications)
           Any Nissan Dealer (300Z applications)
 

       Sources for Tremec 3350 Transmission

           Dark Horse Performance
           16617 SE 134th Renton, WA 98059
           (206)227-7778 Fax (206) 277-3893
          http://www.darkhorseperformance.com/

           Forte's
           1-617-647-1530
           474 Moody St.
           Waltham, MA.
           http://www.ultranet.com/~fortes/tre.htm

           ABE Transmission and Gear Company
           Outside CA (800) 821-0308
           Inside CA (800)631-8756
           http://www.abetrans.com/

      Sources for JT5 (modified Borg-Warner) Transmissions

           Nearly all  of the big Jaguar Suppliers Carry the JT5

           Medatronics Corporation (manufacturer)
           1717 Avenida Del Sol
           Boca Raton, FL 33432
           561 447 9594
           Fax: 561 995 9234
           http://www.gearzone.net/

           Replacement parts can be ordered from any Borg-Warner source
 

       Sources for TX51 (Modified Tremec)

           Vicarage USA
           5333 Collins Avenue #502
           Miami Beach, FL USA 33140
           (305) 866-9511 phone
           (305) 866-5738 fax
           http://www.vicarage-jaguar.com

           Terry's Jaguar Parts
           117 E. Smith Street
           Benton IL. 62812
           Phone (800)851-9438 Fax(618)438-2371
           http://www.terrysjag.com/

          Waterloo Drivetrain  Systems (manufacturer)
          4700 Staggerbrush  Road
          Suite 212
          Austin, TX 78749
          Phone: 512-899-9788  Fax: 208-279-4333
          http://www.waterloo-dtr.com/

      Sources for Getrag Transmissions

           SNG Barratt
           +44 (0)1746 765432
           fax (+44) (0)1746 761144
           The Heritage Building
           Stourbridge Road
           Bridgnorth, Shropshire. WV15 6AP

           Metricmechanic, Inc. (BMW specialist)
           505 East Main
           Richland MO, 65556
           Phone: 573-765-1269  Fax: 573-765-4216

      Sources for Richmond Racing Transmissions

           Gran Turismo Jaguar
           216 259-5656
           4285 Main Street
           Perry Village, OH 44081

           Forte's
           1-617-647-1530
           474 Moody St.
           Waltham, MA.
 

    Sources for Toyota Tranmsission Kits

           Dellow Automotive Pty LTD
           37 Daisy Street
           Revesby, NSW 2212
           PO Box 43 Revesby North 2212
           (02) 97744419 fax: (02) 97744783

           Conversion Components LTD
           17 Victoria Street
           Waihi 3061, New Zealand
          +64 (7) 863-8509 (Phone)       +64 (7) 863-6354 (fax)
           http://www.conversioncomp.co.nz/
 
 
 
 

Copyright © 2000 by Michael Frank all rights reserved. This page may not be copied for any purpose without permission of the author.