4x4 noise

[biochemist]

Hello again, OK I am refining an earlier post. Occasionally, when stopped, if I press the 4Hi button and then push the gas I hear a ratcheting noise for a second or two the it engages and goes forward as it is supposed to. This has only happened a few times, usually it engages and off we go with no extra noise. Dealers have explained to me that when stopped the front diff has sleeves that cannot line up properly and it will/can make that noise for a sec or two until everything meshes together (sounds like a fast ratchet...maybe or a fast low pitched series of clicks, imagin if you put your finger in bike spokes when they were turing fast and the noise they would make against the spokes). This has only happed 5-6 times....for your conv. let us say it would only happen 1 out of 70 times....not very often I know but what do you think, thanks ....dealers say they have heard it, no problems just helps to be moving a bit when pressing the button and since the noise is rare I am inclined to believe them.....

 

PS...the same thing could happen with a manual shifter too, right...they have the same motor in the front that engages the front diff?

[biochemist]

OK, tested more, no issues, called and went to a dealer this morning, all is apparently normal. I explained in detail what is happening (albeit rarley) and they say normal if sitting still and engaging 4Whi, they said do not waste my time to bring it in...three dealers said this!! I guess they are honest Anyway, they explained to me what was happening and said they would expect it to make that noise once in awhile anyway if pushing the button while sitting at a stop...it was just the transfer case gears finding each other to engage and without moving they can be misaligned..and have to "hunt" which is the noise. Anyway, I have been told to not worry about it and they have heard it all before with absolutley no issues arising from this type of noise. So, that is what I know, anyone else? I think we have covered this but any additional comments are appreciated but I guess it is a non issue, hopefully, just that this ismy first 4x4 and I get concerned easliy...they also told me about the manual shift option and sometimes they have to move the truck a few feet before they can shift into 4x4 mode...so this is not abnormal at all... have fun in forum land

[71GMC_3/4T]

If you're sitting still and put it into 4x4, turn the steering wheel back and forth a little to help the front end lock in. The splines need to align before it's really in 4WD.

The worst thing is when you shift to 4WD and it goes whiiirrrrrr-clangk! That means your back wheels were spinning and the front end engaged with a vengeance. It also usually means an expensive trip to the dealer to fix what you broke. A friend of mine experienced this scenario first hand.

If you're rolling along and your fronts are turning the same as your rears, you should have no problem at all shifting on the fly.

If you're stopped, or your rears aren't spinning the same speed as the fronts, beware, you're lookin' for trouble! Avoid it!! Kind of a common sense thing...

[biochemist]

Thanks, I figured that is what is happening, but know little else. The service manager assured me that these transfer cases and front ends are tough and that clanks, bumps and clunks will not hurt anything (you know howit soounds when going into 4lo ) . I suppose if abused it would not be a good scene, but good call...actaully I have heard the whirrrr---clank thing once and it really was not that loud, these other noises were I think the whirrrr noise but no clank at the end...I guess because I was not spinning my rear tires i suppose, just easy on the gas and only made the noise for a second or two. I have also been told that the factory has told the dealerships that you back wheels can be spinning at up to 30 mph....and then you can hit the button. They said it is loud and you may experience a loud noise and bang from the transfer case, but will not hurt anything....I have a feeling what you guys are going to say about that , but if needed adn you did not think ahead and headed for trouble, you may need that type of engagement... I guess your friend had a different experience, what kind of truck did he have, new..old..? Thanks for the comment. I think I will just be moving from now on if at all possible. Thanks agian,

Tony

[71GMC_3/4T]

My buddy had an old S-10, probably around '85 or so. He was stuck in mud, spinning, and put it in 4HI on the fly. I had an '83 S-10 and never had a bit of trouble with it.

 

They say it's okay to engage it at 30mph rear wheel spin? I think I'll pass!! Loud noises and bangs are only good on the firing range for me, thank you...

[biochemist]

My buddy had an old S-10, probably around '85 or so.  He was stuck in mud, spinning, and put it in 4HI on the fly.  I had an '83 S-10 and never had a bit of trouble with it.

 

They say it's okay to engage it at 30mph rear wheel spin?  I think I'll pass!!  Loud noises and bangs are only good on the firing range for me, thank you...

 

<{POST_SNAPBACK}>

 

 

 

Yep, confirmed with 3-4 different service managers (small dealerships, large dealerships etc...). Now, they do not recommend this daily, but in a pinch once in a while it is fine if you are driving up an icy hill and spinning 30-40 mph and sitting still and cannot stop and go back down....go ahead and push it. [i did this sort of thing once but only at 10-15 mph and it just locked in and went without much sound at all]...I totally agree with you, not good to do and will hopefully never have to do it again, but I guess it is nice to know the factory is aware and the components can take it if you need it . The guy(s) said Chevy has told them this is acceptable as long as you are not going over 30-40 mph (spinning while going nowhere)...doing it at 60-70 just sitting there would also make a very loud noise....obviously It is not in the manual because they probably do not want people (read stupid also) doing it all the time....cause I am sure if you make it a habit you would wear it out pretty fast... bottom line, They said you may not like the sound it may make but it will not hurt anything

 

The clank is just a gear mesh noise and all these guys say the new 2005 models do it when the move them for snow removal...sometimes they have to go forward or reverse for a foot or two before they engage and if it is the pushbutton model they make that noise I described earlier (ratcheting)...just depends on the orientation of all the components in the transfer case front end etc...three or four service guys (service managers too, even at the dealer I get my service done) said do not even bother bringing it in because this is not a problem and they would actually expect to hear a noise once in a while for a second or two while the gears are finding each other and the front end was engaging... (cannot really remember the technical terms but something along those lines)... if you engage 4Hi sitting still...bottom line, the clicking or ratcheting noise I described earlier is normal to hear occasionally. One guy said a new Colorado was in there for that noise and everything was fine...same deal. So I guess hearing this ~1 out of 50-75 times of engagement let us say or rarely, is not a big deal. I just worry about stuff like that...little obbsessive I suppose. Anyway, that is the deal on the whirl or ratchet noise and the clank you may hear if your wheels are spinning and you push the button. your friends truck was quite old and I am glad to know it was still kicking at 20 years old....or however old it was when that happened...probably spinning quite fast also I would guess?......thanks again...always interested to know what you think....