need second opinion re: input/output shaft bearings?

7 days ago I was coming to a stop from about 50 mph and felt my car jum jump jump as I was pressing down on the breaks. Light turned green and heard knocking noise like some thing was loose. It only happen whe
slowing down and then from a stop accelerating. Once I reached about 35-4 mph the noise was gone. I actually drove right in to a Benz repair shop They could not find anything wrong. That was last Wednesday. Then thi past Saturday it happen again(so 4 days later after not hearing anythin at all). I had my friend who works and restores very expensive porches ge into the car and listen and drive with me, he said it sounded like th torque converter. I then did not drive it all weekend til I could bring i back to the same place. They called me and told me that it was the bearing in between the input and output shaft. He said he might have to rebuil tranny if the bearings had exploded. Question1 : If this was going on wh couldn't they find that to begin with? especially if the transmission i supposedly affected. They said they did a full check and found nothing. I tranny was going out, wouldn't they have felt,heard,seen that?Question 2 After I told them where it sounded like it was coming from (torqu converter) they then told me that it is not the torque converter rathe bearings that need to be replaced and the way he made it sound he had t take apart the Tranny in order to get to the input output shaft and onc in there could be a good chance a Tranny rebuild would be in order. Thi is the first time I have taken my car to this place, it was on my way t work so I dropped it since it was close. Would love a second opinion base on what he told me and what I said was going on. Also if that does soun right and true how much would reparing the bearings cost and how muc would it cost if the bearings and the tranny need to be replaced/rebuli
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The "jump jump while slowing down" sounds like a sticky solenoid for TIC (torque converter clutch). The TCC connects the engine directly to the automatic transmission (then to the drive wheels). This way the torque converter is bypassed so fuel efficiency is better. TCC should only engage above certain speed, say 35 mph, and disengage automatically at lower speed. If the vehicle speed is too slow this direct connection will stop the engine (just like in manual transmission).
I am not sure if Mercedes ever uses TCC. I suspect they don't since I don't recall any wire going in the front of transmission box. There is kick-down solenoid but it is at rear. Also, you did not mention your vehicle maker, model and year so the above information may not apply at all.
I don't think bad bearing will cause the problem you describe. Bearing problem does not go away because of speed. In fact, higher speed should make bearing worse. I would take the car to somewhere else.
denourse wrote:

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I'm thinking engine /transmission mounts, drive shaft support or flex disk.

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It is too hard to say what is wrong with your car if you don't mention what model and year you have.
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