Transfer Case or Front Diff- PLEASE COMMENT

biochemist · January 9, 2005

Let me try again Last night I was in a snowy lot and 2WD was not getting it done...so I stopped, pressed the 4Hi button and then pressed the gas (yes I waited until the ligt stopped blinking). I then heard a very fast clicking noise, sort of like to gears grinding against eachother or trying to shift a manual without the clutch pedal all the way down. I am not sure but the rear tires may not have been moving either. did not really feel any movement. So I waited ~4 seconds for that noise to stop and then pressed the 2W button then autotrac, everything is fine, 4Wh is fine also....I used it again, no problems. what Happened??...was this just a one time thing? Did I hurt anything? a symptom of a larger problem to come?...........thanks

Tony

biochemist · January 9, 2005

OK guys, went to thelot this morning...stopped, 4WHI button pressed....it did the same thing, click.......then as it slowed down it locked into 4x4 mode....SO, I guess the truck should be moving when you press the button? I did test it a few more times and I notices it will not behave this way all of the time. Sometimes when I press the gas it clicks into 4x4 mode and takes right off, sometimes, when I am coasting it will just go period with no additional engagement noises? Could someone explain what is up, I think I get it but help is wanted,

Tony

Bish · January 9, 2005

OK guys, went to thelot this morning...stopped, 4WHI button pressed....it did the same thing, click.......then as it slowed down it locked into 4x4 mode....SO, I guess the truck should be moving when you press the button? I did test it a few more times and I notices it will not behave this way all of the time. Sometimes when I press the gas it clicks into 4x4 mode and takes right off, sometimes, when I am coasting it will just go period with no additional engagement noises? Could someone explain what is up, I think I get it but help is wanted,

Tony

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Ideally, you should be moving whenever you shift the pushbutton. Without movement, the gears cannot lock together and I suspect that the clicking you hear is either the actuator or the gears tapping. Even very slow movement is better than none. I believe the only time you are supposed to be stopped is when you shift the T-case into nuetral.

Good news is I doubt you hurt anything. I suggest you try shifting back and forth a few times while moving. If you get no noise, forget about it.

facn8me · January 9, 2005

There is an electric motor on the dif that engages the axles. The motor is conected to a shift fork that slides a collar onto a gear(axles). There is a device called a sychronizer that lines up the collar and gear for somewhat smooth engagement. when you are stopped and press 4wd the motor starts to move the shift fork, it is stopped part way beacause the sync hasn't lined up the collar corretly(nothing is moving) so the collar and gear teeth start grinding due to lack of engagement when you try to take off. The axles and carrier are stopped when you are stopped if the collar did not line up the collar splines and the axle splines via the sync it will make noise when you try to take off. Hope this helps.

biochemist · January 9, 2005

There is an electric motor on the dif that engages the axles. The motor is conected to a shift fork that slides a collar onto a gear(axles). There is a device called a sychronizer that lines up the collar and gear for somewhat smooth engagement. when you are stopped and press 4wd the motor starts to move the shift fork, it is stopped part way beacause the sync hasn't lined up the collar corretly(nothing is moving) so the collar and gear teeth start grinding due to lack of engagement when you try to take off. The axles and carrier are stopped when you are stopped if the collar did not line up the collar splines and the axle splines via the sync it will make noise when you try to take off. Hope this helps.

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Thanks guys...I called a dealer that has service on Sunday and he said pretty much the same thing...will not hurt anything, just not lined up just right to engage properly. It seemed to work fine earlier, but did due it one time when I was stopped and not moving when I pushed the button. I guess it was poised just right not to lock in as it should and i needed to move a bit, seems to be consistent with what people are saying here. I will probably get it looked at just to make sure but I tihnk everyone is right. Thanks a bunch I am much relieved,

Tony

biochemist · January 9, 2005

There is an electric motor on the dif that engages the axles. The motor is conected to a shift fork that slides a collar onto a gear(axles). There is a device called a sychronizer that lines up the collar and gear for somewhat smooth engagement. when you are stopped and press 4wd the motor starts to move the shift fork, it is stopped part way beacause the sync hasn't lined up the collar corretly(nothing is moving) so the collar and gear teeth start grinding due to lack of engagement when you try to take off. The axles and carrier are stopped when you are stopped if the collar did not line up the collar splines and the axle splines via the sync it will make noise when you try to take off. Hope this helps.

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Sorry, SO YOU think this is normal in this case and will not damage any components? Tony

facn8me · January 9, 2005

Yes it is normal. It is not designed to engage at a stop, although it may. I believe my manual says to expect some noise. If you are worried that you may have done damage warm up the front diff in 4wd a bit then drain and refill. check the old fluid for metal contamination. Although you will usually find a little metal it should not be glareingly obvious big metal flakes.

biochemist · January 9, 2005

Yes it is normal. It is not designed to engage at a stop, although it may. I believe my manual says to expect some noise. If you are worried that you may have done damage warm up the front diff in 4wd a bit then drain and refill. check the old fluid for metal contamination. Although you will usually find a little metal it should not be glareingly obvious big metal flakes.

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Thanks for the info, it engages fine I think you hit it, you should be moving...if it it stopped it may or may not engage, depends on the orientation of the components I suppose. Sounds exactly what went on, have every experienced this type of noise (fast clicking) in your truck, I see you have a 03...? Thanks for the info,

Tony

facn8me · January 9, 2005

mine has the the manual shift although it has the same front diff and elec motor as yours. I have never tried to engage mine at a stop. I usually kick the tranny into neutral first at 10mph or so then pull back for 4h forward for 4 low then drop it back into drive.

biochemist · January 9, 2005

mine has the the manual shift although it has the same front diff and elec motor as yours. I have never tried to engage mine at a stop. I usually kick the tranny into neutral first at 10mph or so then pull back for 4h forward for 4 low then drop it back into drive.

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OK, I just assumed you have the same setup as I. I assume you have heard this on other trucks though? I hate being paranoid, but would feel much relieved if anyone has actually heard this themselves on a pushbutton setup. I know things make noise under differing circumstances, and I think you guys have it right, just want some reassurance. Thanks for the help

facn8me · January 9, 2005

Although I do not have the same setup as you I am a ASE certified master automotive tech with a master in medium heavy truck also.

PER the manual:

Shifting into 4HI or AUTO 4WD

Press and release the 4HI or AUTO 4WD switch. This can be done at any speed (except when shifting from 4LO), and the indicator light will flash while shifting. It will remain illuminated when the shift is completed.

Shifting into 2HI

Press and release the 2HI switch. This can be done at any speed (except when shifting from 4LO).

Shifting into 4LO

To shift to 4LO, the ignition must be in RUN and the vehicle must be stopped or moving less than 3 mph (4.8 km/h) with the transmission in NEUTRAL (N). The preferred method for shifting into 4LO is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Press and release the 4LO switch. You must wait for the 4LO indicator light to stop flashing and remain illuminated before shifting your transmission in gear.

Notice

Shifting the transmission into gear before the 4LO indicator light has stopped flashing could damage the transfer case. To help avoid damaging your vehicle, always wait for the 4LO indicator light to stop flashing before shifting the transmission into gear.

It is typical for your vehicle to exhibit significant engagement noise and bump when shifting between 4LO and 4HI ranges or from NEUTRAL with the engine running.

If the 4LO switch is pressed when your vehicle is in gear and/or moving, the 4LO indicator light will flash for 30 seconds and not complete the shift unless your vehicle is moving less than 3 mph (4.8 km/h) and the transmission is in NEUTRAL (N). After 30 seconds the transfer case will shift to 4HI mode.

biochemist · January 9, 2005

Although I do not have the same setup as you I am a ASE certified master automotive tech with a master in medium heavy truck also.

PER the manual:

Shifting into 4HI or AUTO 4WD

Press and release the 4HI or AUTO 4WD switch. This can be done at any speed (except when shifting from 4LO), and the indicator light will flash while shifting. It will remain illuminated when the shift is completed.

Shifting into 2HI

Press and release the 2HI switch. This can be done at any speed (except when shifting from 4LO).

Shifting into 4LO

To shift to 4LO, the ignition must be in RUN and the vehicle must be stopped or moving less than 3 mph (4.8 km/h) with the transmission in NEUTRAL (N). The preferred method for shifting into 4LO is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Press and release the 4LO switch. You must wait for the 4LO indicator light to stop flashing and remain illuminated before shifting your transmission in gear.

Notice

Shifting the transmission into gear before the 4LO indicator light has stopped flashing could damage the transfer case. To help avoid damaging your vehicle, always wait for the 4LO indicator light to stop flashing before shifting the transmission into gear.

It is typical for your vehicle to exhibit significant engagement noise and bump when shifting between 4LO and 4HI ranges or from NEUTRAL with the engine running.

If the 4LO switch is pressed when your vehicle is in gear and/or moving, the 4LO indicator light will flash for 30 seconds and not complete the shift unless your vehicle is moving less than 3 mph (4.8 km/h) and the transmission is in NEUTRAL (N). After 30 seconds the transfer case will shift to 4HI mode.

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OK, I wasn't questioning your knowledge at all, I am just obsessive about this kind of thing and wondering about the playing-card-in-the-spokes sound I heard (a couple of times when I pushed the button while sitting still and then pressed the gas). I know you are way above me mechanically from your first post. Just wondered if I am being clear about the noise and if anyone with the same rig has heard the same noise. Thanks for the info from the manual, I have read that, I guess that is a noise but they are not too specific..."engagement noise and bump"...the former is the clicking and the bump is when it finally locks into place? I guess, just did not read it that way......I thought this was for 4LO only shifting, it indeed does sound like engagement and bump....4Hi or auto is ususally unnoticable....except the latest times that led to the noise mentioned above. thanks agian

biochemist · January 9, 2005

OK, tested AGAIN this evening, buttons seem to work fine, no clicking, autotrac is smooth, even at brisk takeoff (on snow mind you) 4WHI engaged, all I ould hear is the motor and a very slight bump....as it always as done. I think it just that the truck was not moving and the parts could not line up...as you all said. Thanks for all the replies, this form is where it is at talk to you all later,

Tony

Kgry · January 10, 2005

Hmm, I've shifted into 4hi a bunch of times while stopped. No unusual noises or problems. I have the manual shifter.

biochemist · January 10, 2005

Hmm, I've shifted into 4hi a bunch of times while stopped. No unusual noises or problems. I have the manual shifter.

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I have the autotrac system....dealers say they have heard it, not everything is lined up just right sometimes. Say the 05, 02, 03..04 do it occasionally (they notice when moving them for snow removal, sometimes has to move a little before the front engages), no big deal, do not even think I sould bring it in for them to look at. Only happend twice, while sitting still, cannot get it to happen again, I guess it has to be just right! . 99% of the time, even at a stand still, it engages no problem, small motor noise then a slight bump. these two times were just a hiccup I guess? Any other suggestions. It is new so maybe it needs to break in?