GordonB

This morning I did a test drive of a new '08 RX350. We drove west of Denver up I-70 on the long 6% grade up into the mountains. I noticed that the transmission kept hunting for gears - shifting up, then down, and up again. I tried to keep at the 65 mph speed limit but the tranny kept shifting up and the speed would drop back down to about 55-60. So I would give it more throttle and it would downshift and just as I thought I would be cruising up the mountain at 65 it would shift again and my speed would drop. This was annoying and I had hoped for better performance. Is this typical of this transmission when driving in the mountains at altitude? Or am I just too accustomed to my diesel truck?

Bernie

Denver, CO

Check out this post from the LOC site.

http://us.lexusownersclub.com/forums/index...ic=41598&hl

I just joined this forum in search of information on the very problem that you are describing. My new RX350 bothers me the most in slower traffic situations by downshifting and giving the appearance of a slipping transmission. This car only has 3000 miles on it, and I have already taken it back to the dealership with this complaint. The mechanic did acknowledge the problem on a test drive, and then told me that it was a normal function. He described the transmission as a "Learning Transmission", and said it would get used to my driving characteristics after a while. He also acknowleged that the ES350 has the same transmission, and does the same thing.

If anyone out there reading this forum has had the same problem, or knows of any fixes, please let me know

Thanks,

Gordon Fish

Sandpoint, ID

My recent trip was 3.400 miles from Northern CA through Yellowstone NP, Glacier NP, and return through WA and your OR. This was in an 08 RX 350 and it did the same frequent downshifting at high speed. The point is that Lexus must be satisfied with that quirk in the car since it still exists with the 2008 model that has plenty of HP to handle slight lugging. The head mechanic at a Lexus dealer said that the transmission has two overdrives so cycling through all three of the "D" gears is a usual issue.

The worst is when going up a hill and every 2-3 seconds it decides to lurch into another gear. It does not make for pleasant or peaceful driving. For some reason, the constant shifting is hard to get used to and is startling when it occurs.

I ended up leaving the cruise control off and tried to feather the throttle just enough so the downshifts would not occur. Speed was lost on hills but it is a fair price to pay for not being constantly jerked around. Your solution sounds similar.

As Clinton might say, "I feel your pain." ;)

I just joined this forum in search of information on the very problem that you are describing. My new RX350 bothers me the most in slower traffic situations by downshifting and giving the appearance of a slipping transmission. This car only has 3000 miles on it, and I have already taken it back to the dealership with this complaint. The mechanic did acknowledge the problem on a test drive, and then told me that it was a normal function. He described the transmission as a "Learning Transmission", and said it would get used to my driving characteristics after a while. He also acknowleged that the ES350 has the same transmission, and does the same thing.

If anyone out there reading this forum has had the same problem, or knows of any fixes, please let me know

Thanks,

Gordon Fish

Sandpoint, ID