Upgraded 16 inch wheels. Car serviced by Jaguar South. Transmission conversion kit and installation by Jaguar South at an estimated expense of over $11,000. Air conditioning. 1992 Jaguar XJS Convertible presented as Lot T77 at Dallas, TX Tremec 5-speed manual transmission by the Driven Man 5 Speed Conversion Kits - Since 1976, Terry's Jaguar has been in the business of supplying a wide range of parts for Jaguars - everything from XK120, XK140, XK150 and all XKE / E-Type Parts models right through to the latest Jaguars on the road. The published stats rate the Jaguar V-12 at 5000 rpm. With the large steps between gears on a three-speed transmission, the engine should be taken to the redline of 6500 before shifting to optimize performance. The GM 400 slushomatic transmission, of course, was designed with the 1950's-design pushrod V8 in mind. 5 & 6 Speed Transmission Conversions. Gear Ratios of Various Options. T-5 Manual Conversion. In the latest Jaguar Journal, on page 28, there is an article about a T-5 manual conversion kit developed by Predator Performance. There is a choice of 5th gear ratios available. My trusty 300k mile XJ6 needed something to help keep her young, and I decided the best thing would be a manual gearbox. This was a 5-speed Getrag 265 from a 1981 BMW 528i. 1990 Jaguar XJS. This 1990 Jaguar XJS V12 was the very few recipients of the Keisler 5-speed transmission swap, utilizing a 5-speed Tremec transmission. The rare Keisler manual transmission conversions are quite well respected, and are known for the quality of their engineering and workmanship. No Reserve Viper V10 Swap: 1989 Jaguar XJS Convertible. but either way performance should be substantially increased by the Dodge V10. All early Viper engines like this were paired to a Borg-Warner T56 6-speed manual, and we've seen a fair number of LS swapped XJS' running the same Manual Transmission Fluid Change Cost The average cost for a Jaguar XJS manual transmission fluid chan