When cold I back up, put the vehicle in drive and then even after waiting when I accelerate forward, there appears to be a slipping motion.

Anyone else have this problem?

 

When driving down hills, around 35-45mph and with slight brake pressure applied, I notice sometimes my GX shifts down to a lower gear. Sometimes it shifts down 2 lower gears.

Has anyone had this happen? Is this supposed to be a feature?

 

Yup it does that, downshifts to I guess assist in engine braking, weird at 1st but you get use to it.

If you don't want it downshifting don't touch the brake

 

It seems inconsistent. I can repeat it when I want to.

 

so can i

 

Sorry, mistype. I cannot repeat it when I want to. Steady brake pressure down a hill. My belief is if you apply stead brake pressure and the vehicle does not slow, or does not slow at a sufficient deceleration curve, then maybe it downshifts.

But like I said, it always happens when I'm not expecting it, not when I'm trying :-)

 

I get the same thing -- very odd feeling.

 

Could it be DAC related?

 

I don't think so because that function has its own control button and it is only available in low range. I have used this feature before btw and it is quite nice.

 

That's part of the automatic transmission's brain thinking. It's just hill logic. Normal. It will downshift if you go downhill or hold the gear when going uphill.

 

I don't consider it normal when comparing other vehicles. Toyota MFR has not had this feature in any of the 6 trucks I have had since 1986 before this one. One of these has been the RX330. Automatic Transmissions shifting down on their own is not normal or certainly common in the industry. In fact I have never seen it on any other vehicle manufacturer.

I feel it can be OK, it is just that they way the transmission is tuned it is too obtrusive and surprising.

 

Only time it down shifts if when Im going down a hill or coasting downward and I tap the break, I'll feel it down shift but usually it is a good thing, never had a problem with it, if I tap the gas it won't downshift

 

One thing that rarely comes up when comparing vehicles against Lexus is the transmission. The Lexus transmission has to be the smoothest in the industry - IMO. Shifts are barely noticeable during normal driving and it keeps power on hand at almost any speed and RPM.

Mercedes doesn't have it, I know GM and Chrysler don't. I'm uncertain about BMW.

It's also a big reason that you'll get decent 0-60 times despite not having the largest amount of horsepower on the block (pun intended).

 

Very good point although when comparing the GX to the BMW or ML I would only consider the loaded X5 4.4 or ML 500 but then the Lex is so much more, and with GM can you even compare

 

I agree; it is pretty smooth. Have you ever come to a complete stop and then barely pressed the accelerator to very slowly move through the gears? Each shift is almost imperceptible. What I don't like, however, are the abrupt downshifts when braking. I think they could have done a better job at rev-matching or something.