Need help diagnose a problem

[Ishman54]

Okay, so I have a 2001 Mazda Protege LX 1.6 at 170k miles.
Had a rebuilt Transmission put in two years ago at 139k Miles. It's an Automatic
The car shakes terribly when it's in drive at a light or something. It only shakes in Drive, neutral it idles like a beaut, with the A/C on it idles smooth.
thats one of my problems, the second has been going on about three weeks, the car doesn't want to shift until like 5500 rpms when getting on the highway or it just wont shift at all or until I take my foot of the accelerator. Earlier this morning I was taking my S/O home from breakfast and was accelerating through a signal light when it like jerked to a stop between shifting, that really scared me because at this point I do not have the money to drop another $3,000 on a tranny. I've been around cars a while so in my opinion it felt like instead of shifting up to 3rd it switched low backing into 1st, it kinda felt like I hit an animal when it happened. Checked all the fluids they looked great. Can someone help me?

 

[concept]

First issue may be a broken motor mount. There is also a chance that shifting is being adversely affected by the engine's rotation under acceleration torque. If this is the case. ignore my next suggestion, but still show the manager what your car is doing.
As to your tranny, if the motor mounts are good, what you describe should NOT happen. Have the shop manager drive your car and tell him that you expect the tranny to be fixed, as your OEM transmission lasted 139K miles; therefore, you suspect a possible rebuild issue.

 

[Ishman54]

I'll look into the motor mounts this week Monday will be my weekend so ill start there, thank you for your help.