repooc11

I have a 2003 RX 300, 205K miles. I notice that when driving the front end lurches left. This seems to correlate with acceleration somewhere about 45-50 mph. It can be more pronounced when cold or when driving on uneven surfaces. Mechanic says drive shaft or transmission. Money is very tight right now. I was thinking about asking the mechanic to perform the above flushing procedure is hopes of a cheap way out. Thoughts?