As you all must know who have a automatic Jaguar has the J gate, on the left are 2, 3, 4 gears. What is the consensus about shifting these cars manual or semi manually. I doubt they are dual clutch transmissions. Also, most cars with automatic with a manual shift mode have the manual shift mode spring loaded so you slap it into gear, either plus or minus.

 

Our tranny's are neither dual clutch nor steptronic. I've heard both good and bad things about doing this. Some say they do it all the time, others will say never to do it unless you're looking to get a new tranny. Lets see if we get some more info, as I am curious too. I assume it can't be bad for the car, after all it is electronically done...

 

The J-gate wasn't really designed for that type of use. It was more intended to be used as a gear limiter like a regular PRND shifter. Our transmissions are conventional automatics with torque converters.

I don't know if these trannies are strong or not. Personally, for the Jag I only use it to limit gears and to engine brake, rarely ever to up/downshift through the range. Sometimes I'll lock the transmission in a lower gear in anticipation for an acceleration/passing scenario. In my Mercedes with TouchShift (Mercedes speak for Tiptronic) I would often use it to shift myself but the engine and transmission in that truck were bulletproof. Not sure I have as much faith in the components in the Jag.

 

The most I do with mine is going into lower gear going down hill, I've always done that so I don't ride the brakes. I live in the mountains of Pennsylvania, and there are some large mountains. I've never had any trouble doing this in any of my Caddy's, but this is my first cat, I'd like to get some feed back on this too.

 

The subject of manually shifting an automatic tranny was brought up awhile ago. The short of that topic came to be that if you are manually shifting it under normal acceleration and shifting the car about where the auto tranny would shift it, no crime, no foul. Now, if you are wanting to really get on the gas hard and pushing the car up to redline (holding the gear as long as possible), then the likelihood for damage is dramatically increased. So, it is a yes and no answer. The question is how you are driving the car. How the car shifts between the different gears doesn't change, it is the shock to the car of going from one gear to another and the RPM difference between them. obviously, the more RPM change the engine has to go through during the gear change, the more of a stressor it will be on the tranny. The big difference is if you are manually shifting the car and always holding it to a much higher RPM, when you let the tranny shift, it is going to be stressed that much more.

 

when an automatic transmission shifts gears, it has to temporarily disconnect the drive from the engine while it sorts out the gears. Generally the engine's energy goes into heating up the fluid, and by wearing clutch bands inside the tranny.

If you shift manually often, and you dont manage the engine's power manually, then you are asking for trouble. When in "D" the computer is able to control the amount of power.
It is your responsibility as driver to manage the engine's power during manual shifts. If not you will cause wear on the fluid and the moving parts of the transmission. just lift your right foot as you shift and only get back "on it" when the next gear is engaged. Practice will make this smooth.

There is nothing magical about it. Energy is always conserved inside a system. Highshool stuff.