1997 XK-8 convertible, had my old transmission go out and installed another used one from a mildly wrecked car. It's worked well but gave me a fault after a few months that I realized happened when I shifted from reverse into drive without completely stopping. The fault went away by turning the car off and back on again. I made sure to come to a complete stop before shifting and had no problems.

I then noticed I would also get the fault when I gave the car a little gas in the middle of a tight/90 degree turn. I stopped doing that and the fault pretty much went away for the most part for about a year.

I stupidly hit the gas around a turn two nights ago and now the fault is back with a vengeance and occurring repeatedly and under any condition. As it occurs under repeatable and specific circumstances, I feel like it must be physical and not electrical or internal. This happen to anyone else? I have an appointment with a general mechanic on Tuesday and I'd like to have some leads before going in. HELP!

 

That could be due to the main pressure valve not sealing. Transgo repair kit could be the answer. A foreign car shop that can read Jag codes may be able to identify the problem. A drum failure can result if it isn't fixed, and the drum may be damaged now.

 

This kit?

https://www.ebay.com/itm/TransGo-5HP...-/351708237931

What makes you say this might be the issue? How can you tell if the drum is damaged and what happens if it is?

 

That's the kit. I'm just guessing from your description. If you go to a shop with 5HP24 experience they may be able to read codes and diagnose. The only way to determine if there is damage is remove the transmission and look inside, but if you make the valve upgrade and the symptoms go away you may be okay.

If you do a search for A drum failure you will find lots of threads with descriptions of the symptoms.

 

as unrelated as this might seem, I suggest you check your wheel bearings. I experienced (as have many others) strange transmission behaviors and error messages along with some reduced performance, abs errors and others. All of these errors in my situation were due to a worn wheel bearing that caused the abs ring to go in and out of (physical) sensing range. The jaguar computer couldn't decide what was at fault so it kept me guessing for many months. Checking shouldn't be of much trouble or cost and it is a simple enough first step.
good luck and let us know what you ultimately find.
wj

 

How did you determine this was the issue? Was the solution to replace the bearings or was there more to it than that? All four wheels? Thanks!

 

If I went through a left hand turn at any speed which would cause a bit of side force I would get some fault message and at times the computer would change the manner in which the tranny shifted, braking, etc.In my situation I could 'reset' things by engaging the panic mode with the remote...after it ran its siren etc all of my faults would disappear and I was good to go. I knew the left rear bearing was going out as I heard it click/clunk every now and then...I drove it like that for several thousand miles with the occasional weird messages+behaviours. When it finally wore enough that it always clicked/clunked I could repeat the left turn scenario and always get the messages.
I replaced only the left rear as the other bearings felt tight. The abs reluctor is attached to the shaft and with the loose bearing it literally would move in and out, too far for the sensor to pick up the signal and thus cause the 'fault'.
wj

 

The engine+trans rely on the signals from the ABS sensors. They can be upset by bad wheel bearings (think what is occurring).

 

Would pulling diagnostic codes give me any information?

 

^^ That would be my initial effort....

 

yes of course but those codes won't point you toward the bearing issue, checking the bearings is a 'physical' endeavor.
wj

 

And the actual ABS may be happy enough but due to wobble the rest of the car isn't.

So, +1 on physical checks.