Driving down hill, shifted into lower gear?

[cwest94]

I tried a search on this before posting and didn't find anything.

A couple weeks ago I was driving on some country roads for about 10 miles. The speed limit was 45 and the country roads were steep up and down hills with many twists.

When I was driving down one of the steep sloping hills at 45, my 4Runner shifted into a lower gear and my RPM's went up, it did this a second time 3mins latter going down another steep hill.

Over the past 6 months of driving this 4Runner, it never did that and hasn't done it again since that last time a couple weeks ago.

Is this normal or should I get it looked at?

Oh, is it normal to feel a vibrating feel in the brake pedal ever so often for a second? You can also hear that vibrating to when it happens. It almost sounds like something is priming?

 

[mustangchris66]

Mine does the same thing. Accually I can make mine do it by letting the truck come up to speed ~35mph or higher coasting down any significant hill in "4th" not "D" when I hit the breaks to slow down, not drag the breaks to maintaine speed. I can make it shift to 3rd. The down shift is not in anw way violent and is really smooth.

Hope this helps.

 

[keylay31]

I'm going to say that's not normal. did you have it in D? Sometimes when I let off the gas coming to a stop light, if there's enough time to slow down without applying the brakes, the car will downshift and it slows the car slightly more than coasting, but not significantly, and I've always thought that it was both normal and nice. What you are describing is not the same though, I would probably have your dealer hook it up to a computer and check it out.

 

[swimmer2361]

I believe that the shifting is normal. Im not to sure on the vibration, but if you can "hear it" its probably ABS. Does it sound like a clicking or beeping sound??

 

[4RunnerV8]

The shift is completely normal - the transmission is programmed to identify when moving downhill, and partiularly when the brakes are tapped, it will shift to a lower gear to provide engine braking. Keeps the brakes from overheating. It's becoming fairly common on newer transmissions, particularly trucks. I first wondered what it was, but it is actually a nice feature, particularly on long hill. I don't believe that it was included in the early V6 4 speed transmissions, but it was/is an integral feature of the 5 speed.

2004 V8 SE 4wd

 

[toto]

I'd say that both things are normal.

If you were driving a stick-shift transmission, you would want to downshift when going down a hill in order to use engine braking - the engine itself will dissipate energy and reduce forward momentum in a lower gear. That's easier and better than riding your brakes to maintain speed or slow down on a downgrade.

The vibration in the brake pedal is probably the buildup of pressue in the brake booster. I usually encounter that within the first minute or two of driving, if I notice it at all.

 

[Koz]

The shift is completely normal - the transmission is programmed to identify when moving downhill, and partiularly when the brakes are tapped, it will shift to a lower gear to provide engine braking. Keeps the brakes from overheating. It's becoming fairly common on newer transmissions, particularly trucks. I first wondered what it was, but it is actually a nice feature, particularly on long hill. I don't believe that it was included in the early V6 4 speed transmissions, but it was/is an integral feature of the 5 speed.

2004 V8 SE 4wd

Absolutely, a trans with intelligents. If you are going downhill and let off the gas it will hold that gear. If you apply the brakes (going downhill) it will downshift. This is good technology. On my IS (with the trans mode set at power), it will very aggressively downshifts during hard braking. SWEET!

Koz