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Super Genius
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My 07 Tundra is just a few weeks old now and I love it. No problems except for the following which I have yet to figure out. Hopefully someone here can give me some advice before I make the long trip back to the dealer for service.

A few weeks ago I posted a note in several forums about a metallic clanking noise which seems to be coming from under the front/center area of the truck. The noise only happens once after I start the truck and put it in gear. The noise doesn't happen immediately but it always happens within the first 300-500 feet of driving, then it never happens again until I park the truck and start it up the next time. Originally I thought it was the transmission shifting from 1-2 or 2-3 but I noticed that the noise still occurs no matter how slow or fast I am moving. It also doesn't matter whether the truck is warm or cold, the outdoor temperature is hot or cold, or if it is raining or dry outside: the noise always occurs just once and then never again. It is not a soft noise like a relay clicking or the gears shifting, it is a firm and fairly loud clank like someone striking the frame with a small hammer.

I did some more testing today by starting the truck, switching into 4-HI while still in park, then driving the first 300 feet to listen for the noise. I was amazed to see that the metallic clanking noise did NOT occur, however the truck seemed significantly harder to drive and it took more gas to get it moving and keep it moving. I switched back to 4x2 mode and it drove fine and smooth as usual. This convinced me that the noise has something to do with the 4x2 or 4x4 mode and I was concerned that the truck was harder to drive in 4x4 so I went to an empty level parking lot for some testing.

When I shift into 4-HI mode on the fly the truck switches modes smoothly and with very little noise other than what you would normally expect. It drives ok when moving straight ahead but then when I drive in circles it is significantly harder to keep the steering wheel in position during the turn. It also sounds like one or more of the inside wheels might be spinning and chewing at the asphalt while I am making tight turns but this is reduced or stops when I make wider turns. This is my first 4x4 truck in many years so I am not sure if this is normal behavior or not, but it sure felt odd since I was virtually fighting the truck through the turns while in 4x4 mode. Also, when I switched back to 4x2 mode on the fly the truck would sometimes make the metallic noise again but it was usually not as loud as the initial metallic noise which happens after every startup in 4x2 mode. FYI - my truck does have the LSD, TRAC, and VSC systems and I did not touch the VSC switch during any of the above testing.

So here are my questions:
  1. What could be causing the metallic noise which always happens within the first 300-500 feet of driving after startup, but only in 4x2 mode?
  2. Is it normal for the truck to make a metallic noise when shifting from 4x2 to 4-HI or vice versa?
  3. Is it best to shift into 4-HI from park, on the fly, or doesn't it matter? (I know you need to be stopped and in neutral to shift to 4-LO and this works fine.)
  4. While in 4-HI is it normal for the steering to be harder and/or the inside tires to spin and skip during tight turns?
Any help would be appreciated. I am probably going to get the dealer to check it just in case but I am trying to determine how urgent the situation is before taking a day off work and making the long trip.
 

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So here are my questions:
  1. What could be causing the metallic noise which always happens within the first 300-500 feet of driving after startup, but only in 4x2 mode?
  2. Is it normal for the truck to make a metallic noise when shifting from 4x2 to 4-HI or vice versa?
  3. Is it best to shift into 4-HI from park, on the fly, or doesn't it matter? (I know you need to be stopped and in neutral to shift to 4-LO and this works fine.)
  4. While in 4-HI is it normal for the steering to be harder and/or the inside tires to spin and skip during tight turns?
Well for #1, I can't help you. For #2, yes it is somewhat normal. The automatic engagement of the transfer case when it goes into 4wd sometimes makes Toyotas have this clunking sound. I think it's caused by the gears in the transfer case not quite lining up at first. For #3, it doesn't matter as long as you keep it below the speed listed (normally 62 mph in Toyotas), but it is usually easier to get it to go while moving. #4, yes it's normal to be harder to steer. The front axle is trying to spin both front tires at the same speed, but in a corner, the tires can't. The outside wheel will turn faster than the inside one, but the auto locking hubs prevent this. That causes the hard turning and skipping on dry pavement. Try it in your yard or on dirt, and you will notice that it's easier to turn. The hubs disconnect in 2wd, which makes the skipping issue go away.

I know it may not be the best explanation, but I hope it helps. #2, 3, and 4 are all things I have experienced on every 4wd Toyota I have owned. It's just the way they're made.
 

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  1. [*]What could be causing the metallic noise which always happens within the first 300-500 feet of driving after startup, but only in 4x2 mode?
    [*]Is it normal for the truck to make a metallic noise when shifting from 4x2 to 4-HI or vice versa?
    [*]Is it best to shift into 4-HI from park, on the fly, or doesn't it matter? (I know you need to be stopped and in neutral to shift to 4-LO and this works fine.)
    [*]While in 4-HI is it normal for the steering to be harder and/or the inside tires to spin and skip during tight turns?
Any help would be appreciated. I am probably going to get the dealer to check it just in case but I am trying to determine how urgent the situation is before taking a day off work and making the long trip.[/QUOTE]


I'll try to answer a couple of them.

1. Doesn't sound right to me. Maybe someone else has a better answer.

2. It is normal to hear a noise when shifting into 4HI and out of 4HI into 2wd. However, it should be more of a "clunk" sound that you can also slightly feel through the floor boards or pedals. Doesn't always make a sound though.

3. In park or on the fly, shouldn't matter. It's built to work on the fly. It's not new technology.

4. If you were in 4HI on a dry road surface or even bare and wet pavement you will absolutely experience what you described. Try avoid running in 4WD on those surface conditions. Hard on the front end.

Everything sounds like what you should expect, except the noise when you first start driving in 2wd.

 

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My 07 Tundra is just a few weeks old now and I love it. No problems except for the following which I have yet to figure out. Hopefully someone here can give me some advice before I make the long trip back to the dealer for service.

A few weeks ago I posted a note in several forums about a metallic clanking noise which seems to be coming from under the front/center area of the truck. The noise only happens once after I start the truck and put it in gear. The noise doesn't happen immediately but it always happens within the first 300-500 feet of driving, then it never happens again until I park the truck and start it up the next time. Originally I thought it was the transmission shifting from 1-2 or 2-3 but I noticed that the noise still occurs no matter how slow or fast I am moving. It also doesn't matter whether the truck is warm or cold, the outdoor temperature is hot or cold, or if it is raining or dry outside: the noise always occurs just once and then never again. It is not a soft noise like a relay clicking or the gears shifting, it is a firm and fairly loud clank like someone striking the frame with a small hammer.

I did some more testing today by starting the truck, switching into 4-HI while still in park, then driving the first 300 feet to listen for the noise. I was amazed to see that the metallic clanking noise did NOT occur, however the truck seemed significantly harder to drive and it took more gas to get it moving and keep it moving. I switched back to 4x2 mode and it drove fine and smooth as usual. This convinced me that the noise has something to do with the 4x2 or 4x4 mode and I was concerned that the truck was harder to drive in 4x4 so I went to an empty level parking lot for some testing.

When I shift into 4-HI mode on the fly the truck switches modes smoothly and with very little noise other than what you would normally expect. It drives ok when moving straight ahead but then when I drive in circles it is significantly harder to keep the steering wheel in position during the turn. It also sounds like one or more of the inside wheels might be spinning and chewing at the asphalt while I am making tight turns but this is reduced or stops when I make wider turns. This is my first 4x4 truck in many years so I am not sure if this is normal behavior or not, but it sure felt odd since I was virtually fighting the truck through the turns while in 4x4 mode. Also, when I switched back to 4x2 mode on the fly the truck would sometimes make the metallic noise again but it was usually not as loud as the initial metallic noise which happens after every startup in 4x2 mode. FYI - my truck does have the LSD, TRAC, and VSC systems and I did not touch the VSC switch during any of the above testing.

So here are my questions:
  1. What could be causing the metallic noise which always happens within the first 300-500 feet of driving after startup, but only in 4x2 mode?
  2. Is it normal for the truck to make a metallic noise when shifting from 4x2 to 4-HI or vice versa?
  3. Is it best to shift into 4-HI from park, on the fly, or doesn't it matter? (I know you need to be stopped and in neutral to shift to 4-LO and this works fine.)
  4. While in 4-HI is it normal for the steering to be harder and/or the inside tires to spin and skip during tight turns?
Any help would be appreciated. I am probably going to get the dealer to check it just in case but I am trying to determine how urgent the situation is before taking a day off work and making the long trip.

I can give you my take on Questions 2-4.

2: When you throw the dash switch, it inturn activates a solenoid which engages/ disengages the front drivetrain, and depending whether or not the drivetrain is under load (Accelerating/Decelerating) that noise may be more pronounced. This is how it works on my 04 F150 and 2 previous GM trucks I drove (00, 03)

3: You should be able to shift on the fly between 2wd & 4Hi at any speed, check the manual to be sure, but again, I do this all the time in my F150 and have previously in every 4WD I have owned including Toyota's, although those were older machines, 85 RC SWB 22R, 93 Extracab 22R

4: If you were on dry pavement when performing the tests, this is normal behaviour, commonly called crabbing I believe. The front end is trying to pull
itself in the direction your steering while the rearend is pushing you straight, great in the mud or snow, not so hot on pavement.

As far as question number one goes... Can't help you... Maybe its the trucks testicles dropping as it get's ready for a days work :devil:

I've got a CrewMax arriving in a couple of weeks, if you find that the noise is flaw, let us know, I would want that dealt with before I pick up the truck.

Later
 

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Vehicle Stability Control makes a noise that you are describing right when you begin to move, it is a self check. You don't hear it in 4WD because stability control turns off in 4WD. It is totally normal. It does a self check every time it is started.
 

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The first noise you hear could be an ABS or stability control self test. I know lots of ABS equipped vehicles for years have made funny noises when first starting and moving doing their tests. I don't own an 07 but my 00 does this ABS test after starting.

Your 4wd experiences sound completely normal.
 
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