5R55N Gearbox strange noise

[manu_cyb]

Hello everybody!

Few month ago I bought a 2000 S-Type 3.0 V6 which seemed to be properly maintained by the previous owner. Few days ago a strange noise appeared when the engine is running, like a scratch which increase when I accelerate, no matter if the car is running or it is stopped. I think it's the gearbox because I lift up the hook trying to figure out what's going on, but the sound appears as coming from somewhere under the car, and it's heard louder near the driver's door (it's a left wheel car). I don't know if it has anything to do with this, but a week before the appearance of the noise I took of the battery from my car for ~10 minutes (a friend of mine needed it to start his car) and after I put the battery back, it seemed to me that the gearbox has more hitches while driving in D, especially when I'm slowing down. Then when I tried to drive in Reverse some hitches occurred while the car was still stopped (I was pressing the brake). This R hitches (I think there are 3 hitches before being able to drive normally) are stronger when the engine is cold. Then the noise appeared. No warning light or other unusual things appeared and the gearbox changes in all gears like usual.
A friend of mine who knows more things about cars told me it can be the oil pump from the gearbox. Anyway, I don't take into consideration the option of going to the Jaguar's dealer service, while I know they said that the gearbox is a sealed unit which can be only entirely changed. So I called some automatic gearbox repairer and all of them (I could find 5 or 6) told me that no matter what is damaged, I'll have to pay 400 Euros and the cost of the spare parts needed.
I still hope it can be something more simple and I'm waiting for advice.

Thanks !
  Emanuel.

[Neil]

I do have a small "thump" when I do switch R, no matter what, it's not that big when the engine is warm (tranny oil is warm). Do you experience the same voice in NEutral? Does the strange voice becomes louder when you do switch D (keep the door open so you can notice the difference). If it's louder, then I am sure your torque converter should be replaced. At least the sound disappeared when I replaced torque converter.

Have the tech people checked the tranny fluid level? It's a small screw (additional screw) in the center of drain plug for the tranny....

[manu_cyb]

The noisy sound it's the same in all positions : P, R, N, D. Actually in R and D it's a little lower because the engine rotation decreases. It can be heard as something that when rotating is scratching something else and it's related only to the engine rotation and not to the gear nor the speed (while driving).
Regarding the transmission oil level - is it any schema or some pictures anywhere ? I personally didn't see the bottom of the car but I recently changed the filters, the engine oil and the front brake pads so I asked the mechanic who made all these also to check the transmission oil level and he said he only could find a stopper like a screw which stops a hole but somewhere in the upper part of the gearbox.
I think it's not the differential fluid - the noise is more in the front/center of the car but I'll try to check the fluid there, too.

[Neil]

the upper screw is for oil adding for the gearbox. the gearbox oil level screw is built into the drain plug oil. I will check if I have any pic at home and post it.

[manu_cyb]

I think I found a file where I understand the procedure for checking the transmission oil level.
The file can be downloaded from
http://www.europeantransmissions.com/Bulletin/DTC-jag/Jag/S307-03.pdf

I'll check the level ASAP.