hi i was using my four wheel drive for the first time in my new (used) 03 gmc crew cab and i notice a vibraiting from the front drivers side when i was doing 60mph i have always gone the fast in 4 drive in my ford f -150 and never had a problem and i noticed some guys drag race in 4 wheel drive so is it ok to go that fast or are some guys taking out of 4 wheel drive when they get going. my buddy says the gm doesnt use a 1 to 1 in the front to help it pull better i dont really know what to do should i bring it in and have them look at the front end or is it this normal thanks

what you should do is use periods in your posts. thanks

60? I am not trying to be a wise guy but whenever I've been in conditions that warranted using 4-wheel drive, it wasn't conditions where I would want to do 60.

You can use 4wd in a straight line on the street, DO NOT use it when you are going to be cornering. It will cause driveline binding, and that is not a good thing. When you go around a corner, the front wheels travel a further distance than the rears, and it puts a load on all the parts. It will not break stuff immediately, but it will accelerate wear.

And no, GM does not use different ratios front to rear. Nobody does. It causes driveline bind.

I'm pretty sure they used too use diffrent ratio's in the old days like 4.11 in front and 4.10 in rear. That way the front would alway's be pulling a little to help keep from having the rear end come around under power. But I don't think they do it anymore.
But you used to have to stop to engage 4wd too.

I have never seen or heard of different ratio front to rear unless they had different size tires. Your problem you are comparing a real truck to a Ford, seriously it could be several things. I would just put some weight in the back of your truck so you don't use 4wd it’s not necessary unless you’re in some deep snow or playing. I would suggest using some punctuation the guys will never let it go trust me I know.

I was in 4hi in the snow acellerating from 60 to about 70mph up a hilll and noticed that it was making an odd vibration from the front end, although it could have been stutter bumps in the snow too. Who knows. But it didn't used to do this, I do need to change the diff oil in both ends so maybe that'll help.

You were doing 70 mph in snow?

/Darwin?

I rebuilt a front diff in my cousin's truck a number of years ago, the truck is an '83 /F250. Front diff ratio 4.09, rear 4.10. I though maybe they did that so that it would take backlash out of drivetrain from front to back to cut down on gear noise when in 4WD. Just a guess. My '91 Chev is 4.10 front and back.

What is it with people and punctuation. All i asked was a question i didn't ask to be graded. I was on a highway going straight and punched it from 35 mph. At 60 to 65 thats when i heard the vibrating noise from the front drivers side. It doesn't seem right too me that its making a noise any body have any good input. Thanks hope my typing was insulting this time. :cool:

Start with the basics, check u-joints, slip yoke slop, oil level in front diff. You might even want to put the truck up on jack stands and put it in 4wd and try and duplicate the problem while on stands.

As for minor variations in gearing front to rear, that is all it is, a minor variation. It comes from the mathematical formula of dividing the number of teeth on the ring gear by the number of teeth on the pinion and in all of the cases where the front may be 4.09 and the rear 4.10 it is because the axles are not exactly the same and thus the tooth count is different. That is it! And that small amount is no where near as much as someone who doesn't rotate their tires regulary and has rear tires worn a lot more than the fronts or vice versa.
Some mud racers like to run different ratios to keep the truck running straight in the mud and they will sometimes run a 3.73 up front and a 4.10 in the rear so that the front is constantly spinning faster than the rear. Or some guys will run different size tires, larger in rear smaller in front and offset it with different ratio's.
Good luck with the vibration:grd:

What is it with people and punctuation. All i asked was a question i didn't ask to be graded. I was on a highway going straight and punched it from 35 mph. At 60 to 65 thats when i heard the vibrating noise from the front drivers side. It doesn't seem right too me that its making a noise any body have any good input. Thanks hope my typing was insulting this time. http://www.dieselplace.com/forum/images/smilies/cool.gifWe are not trying to grade you. Its just that using proper punctuation makes it easier to follow and understand what you a person is trying to say http://www.dieselplace.com/forum/images/smilies/smile.gif .




Gary

That vibration at those speeds is normal. The front shaft is very short in comparison to the rear, and I really don't think that 4WD HI was intended to be driven at highway speeds or higher. My brothers suburban has the autoride transfer case (front shaft is always turning) and after his lift the vibration was horrible at anything over 55mph. He went with a dual-cardine (sp?) or dual cv shaft and while this helped with the angles and vibration, you can still tell that when your going 70+ your front shaft is turning. You can "feel" is turning is how i describe it. I think your just gonna have to deal with it, can't see a "fix" for it.

You were doing 70 mph in snow?

/Darwin?


Yup, came around the corner at around 55mph and opened it up on a open road on a straightaway going up a mountain pass, truck didn't even hint at sliding. Did I mention siped Yokohama Geolander AT+ II's rule!? :ro)

I've got the same problem, if you find anything out let me know. I have had the dealer look at the truck about three times now and keep getting told is nothing and all trucks make this noise. In the meantime it keeps getting worse, when I tow my trailer and tractor (winter conditions) I use 4x4 and the noise is very pronounced at about 35-40mph.

I'll update if I find anything out with mine, please to the same for me.

Thanks.

im not one to post much or comment... but... why the hell are you doing 60 in snow?

I dont even use my 4x4 in any of our 4x4 trucks that much. Only time I use it is usually when its over 6" of snow on the ground. Personally, IMO, you dont need 4wd that much. Some people panic and if they start to spin they engauge 4x4, but imo, if you know how to drive right, you dont really need 4wd that often. I get really pissed because my bro barrows my truck to go to the store, and if their is only like .3" of snow he puts 4x4 on. It makes me soooooooo mad. Sorry, just imo 4wd is great when you NEED it, but most of the time you dont. And to be honest with you. on ice, 4wd wont help you that much, and 4wd should only be used when stuck, or you have to go through 6+" of snow, or when your plowing. I mean who cares if you spin a little or slide a little, just dont be stupid while driving in the conditions and know how to handle your truck!

Its sad you see cars piled up and crashed on the side of the freeway, wondering why their car spun out while doing 70 in a snow storm. BTW. How come little old ladies always decide its best to go get some milk and bread when its snowing like 2" an hour!?!?!????

I dont know, I just think alot of people panic and if they start to spin just a little they engauge 4x4 and then turn onto dry pavement and continue to drive straight and turning on dry pavement after the salt trucks have been through wondering why their car is violently shaking. :eek:

Okay im done with my ranting now :) Rock On. :ro)