problems with gear selection

[matrix_canya]

This has been happening for the last two weeks and I am fearful that if the problem remains uncheck I will damage the car beyond repair. My car is a 2006 M35. So while driving fast (avg 50 - 60 MPH. revs about 3500 to 4500rpm) going up an incline to my home everything seams normal. However once I am close to the top of the hill the car always sound like it racing and then suddenly jerks forward once then slow to a hault. The moment the car jerks the display for gear selection on the dash board goes blank and I am unable to select any gears whatsoever. In order to regain control of the vehicle I have to pull the handbrake, switch off the car, push the gear shifter in park and wait for a minute or two or five before restarting the car. On starting everything (even the gears) functions as normal. This happens when I am using either automatic or the manual side of the transmission (it doesn't matter).
About a month ago, I had replace the front and back crankshaft seal because of an minor oil leak. I have alway been uptodate with maintenance

The car is not under warranty. I was told by a mechanic that it was the control valve body which I have since replace but to no avail. I also replace the knock sensor located on the transmission as well
Selling the car now is not an option because of the monies a recently invested in it (trying to fix the bastard) and car has always been faithful to me.
Does anybody out there know what the problem is????? Someone help me please!!!!!

[Ilya]

Is there any codes or a CEL?

[EdBwoy]

Front and back crankshaft seal, I assume you are referring to the rear main seal between the transmission and engine. My wild guess is that someone pulled either the engine or transmission too far from the other and put some kind of strain on the wires that are attached to the back of the engine and are plugged into the transmission. Maybe the harness/plug is loose.
My other guess would be the TCM/transmission control module going out, but it's just curious for this to start happening so soon after repair.

Outside of the main topic, how many miles does your M have? It's not common for the rear main seals to go out in the M35s.

[ArmedAviator]

As Ilya said, check for codes stored first. That may give you a clue.

My guess is an electrical issue. If not that, than maybe low ATF in the transmission. Check for proper fluid level. Be sure to check the fluid level exactly as your manual says. ATF is rather sensitive to temperature.

Besides those two simple checks that you can do in a few minutes, can you post a video of it happening?

[matrix_canya]

there are no codes showing and the car has just under 165000 miles

[matrix_canya]

yes the real main seal was change along with the front crankshaft seal

[Ilya]

Ed might be on to something...who performed the work? Mom and Pop shop or dealer?