[Wannabe]

Hi,
I have a couple of questions...

I've never had a 5 speed auto. So is 5th the overdrive and 1st-4th "normal" gears? Can you select any of the five gears with the shifter, or is there an Overdrive Off button or what?

What does the manual say about towing and transmission gear selection?

My Rodeo has a 4 speed. It does about 2500 RPM at 75 mph in 4th/OD. It doesn't have enough power to pull my boat on the slightest incline at interstate speeds in 4th, and drops to 3rd gear and does about 3500 rpm at 75. That seems kinda high to leave it in 3rd gear all the time, but shifting between 4th and 3rd isn't good either. I have a big tranny cooler installed.

So will the RAV4 drop ONLY to 4th or will it even cruise in 3rd at highway speeds? Is the 5th like a SERIOUS overdrive, such that you could run 4th all day long if pulling a trailer and not hurt anything?

dang wish I had an owner's manual and wish I had the RAV4 to go with it!


Joe

 

[Harold]

I will send you the appropriate section of the manual by email if you change your profile to display your email address. If you don't want to do that, send me an emaill and I will reply with the information. I can't post it publically because I do not have the rights.

 

[karrock]

OK... Just got mine today, but I learned an interesting thing about the new transmision selector from the salesman. :idea:


This photo is of a 4-speed autobox, but it's the same selector as the five, only with a lower range of numbers.

The normal "D" or "drive" position is achieved by pulling the selector down the track straight down from neutral to 3-D (or 4-D with the five-speed). This gives the transmission the full range of 1 through 4 (1-5 with the five). However, tipping the selector to the left while in the 3-D/4-D position disengages overdrive and the transmission will not use the top gearing, otherwise known as "overdrive".

I'm not sure how well the transmission will funtion without the overdrive/fifth gear, but I'd make very, very, very sure before using it like you're thinking about. I'm sure I don't have to write about the many, many possibilities for drivetrain damage, but the very idea of constantly constraining the engine to higher than normal RPM's gives me the heebies. :?

 

[CampingColorado]

I believe that both 4th and 5th are overdrives in the 5-speed box.

 

[Wannabe]

Harold,
thanks for the offer and I think you can see my email addy now!

Mike,
I wonder...does a 5 speed mean an "extra" overdrive or just smaller differences between each gear, than compared to a 4 speed.

Either way is actually good I think.

 

[CampingColorado]

Hmmm, looks like I was wrong (my manual tranny Camry has OD in both 4th and 5th). Could not find specs for the RAV4.3, but the Sienna and Avalon (same transmission) have the following gear ratios:

1st: 4.235:1
2nd: 2.360:1
3rd: 1.517:1
4th: 1.047:1
5th: 0.756:1

So, only 5th is OD.

I'm not sure which 4-speed is used in the '06 RAV, but my best guess is that it's not even an overdrive unit.

If someone could tell me the transmission code from the vehicle specs sticker on the driver's door, I could tell ya definitively (same for the 5-speed). It will be in the lower left of the sticker, and probably look something like:

A/TM: -02A/U241E

Just need the characters after the slash after "A/TM"

 

[Harold]

2006 Rav4 V6 A/TM: -05A/U151F

 

[flyingn]

Camping is correct.
generally 3rd gear in most automatics is a 1:1 ratio (or there abouts) amd 4th is an od BUT in the Rav's 4 speed 3rd is NOT 1:1 ratio, its a 1.4:1 ratio and 4th is 1:1.

 

[CampingColorado]

Thanks Harold! The numbers I quoted above for the 5-speed are correct for the U151F transmission.

I'm pretty sure these are the ratios of the 4-speed (can verify with sticker info):

1st: 3.943:1
2nd: 2.197:1
3rd: 1.413:1
4th: 1.020:1

It appears those are for the 2wd model. It looks like the AWD version has slightly different ratios, but are virtually identical (the same to the first decimal point). That confirms the info from Flyingn, the 4 speed box is NOT an overdrive unit, but is roughly a direct drive (1:1) in top gear.

The final drive ratios are pretty similar between models (I think these are correct, not 100% sure):

2.923:1 (4-cylinder 2WD)
3.080:1 (all other models)

So... what the 5-speed gets you is an overdrive (better fuel mileage on the highway), and a granny gear in 1st (good for getting unstuck, pulling stumps, or getting the jump on those sport-compacts off the line). The spacing between ratios appear to be about the same, with 1st through 4th geared a little lower (higher numerically) in the 5-speed unit.

 

[dj06482]

Thanks Harold! The numbers I quoted above for the 5-speed are correct for the U151F transmission.

I'm pretty sure these are the ratios of the 4-speed (can verify with sticker info):

1st: 3.943:1
2nd: 2.197:1
3rd: 1.413:1
4th: 1.020:1

That confirms the info from Flyingn, the 4 speed box is NOT an overdrive unit, but is roughly a direct drive (1:1) in top gear.

Very interesting, I wonder if this explains why the EPA Highway of the 4cyl and V6 are so close!

DJ

 

[flyingn]

yea.. Just imagine what kinda highway mileage they could get with a 5 speed FWD and the 4.. Betcha 32-33..

 

[CampingColorado]

Yes, I definitely think this explains a lot of the fuel mileage similarity between the two engines. The other thing is that the V6 doesn't have to work as hard to move the car.

I bet this is a big part of the reason why there is no OD in the 4-speed unit. 3600 or 3700 pounds base weight is a lot of weight for 165hp/lb-ft to move around. If there was an OD on that transmission, you might find that it hardly ever shifts there. You might find the same thing with the stick, and would find yourself downshifting to fourth everytime you pulled out in the left lane on the interstate. Or where I live, you'd find that you never put the sucker in 5th to begin with. This is pure speculation on my part.

 

[flyingn]

You are right... But I would think on the highway on level ground 5th gear woudl be fine with the 4. I know ours traveled up and down the Pocono mountains with no problem at all. The 4 has NO problem with power.

Yes, I definitely think this explains a lot of the fuel mileage similarity between the two engines. The other thing is that the V6 doesn't have to work as hard to move the car.

I bet this is a big part of the reason why there is no OD in the 4-speed unit. 3600 or 3700 pounds base weight is a lot of weight for 165hp/lb-ft to move around. If there was an OD on that transmission, you might find that it hardly ever shifts there. You might find the same thing with the stick, and would find yourself downshifting to fourth everytime you pulled out in the left lane on the interstate. Or where I live, you'd find that you never put the sucker in 5th to begin with. This is pure speculation on my part.