Front motor mount movement?

[Ralph50]

2000 Lesabre, 3.8L, 75K miles.
I was checking the motor mount for movement and I see that it moves about 5/8 inch when put into gear with brakes and accelerated. What I also noticed that when I give the engine quick revs, the motor of course moves up a little, but when it falls back down as the motor slows, I feel the thud in the front frame or chassis. It does not seem right that I should feel this. It seems I feel this sometimes when the car is shifting first to second to third. This slight thud, no one else would feel this cause I am in tune to these things. I have always wondered if I had tranny problems, it might be this motor mount. ???

[imidazol97]

Originally Posted by Ralph50

2000 Lesabre, 3.8L, 75K miles.
I was checking the motor mount for movement and I see that it moves about 5/8 inch when put into gear with brakes and accelerated. What I also noticed that when I give the engine quick revs, the motor of course moves up a little, but when it falls back down as the motor slows, I feel the thud in the front frame or chassis. It does not seem right that I should feel this. It seems I feel this sometimes when the car is shifting first to second to third. This slight thud, no one else would feel this cause I am in tune to these things. I have always wondered if I had tranny problems, it might be this motor mount. ???

How much does that mount move up and down when you just push the car while in park? I've wondered how my own motor mount there on '03 is doing. I get similar movement during 1-2 shift like you're describing, which seems like a rough shift but I wonder if it's engine movement giving a vibrating effect during the shift.

How much movement should be found in that mount?

[HotZ28]

You need another set of eyes to watch the trans mount to see if the rubber bonding separates from the metal under acceleration with brakes on.

[Ralph50]

When parked it does not move that much maybe a 1/4 of an inch but of course there is not much tension on the mount. I am going to change it. I definaely feel the thud when the motor slows down and that is not right. I have a 96 Lesabre and it does not do this.