DZLPWR

After hunting this evening i pulled on the the road and noticed a vibration at 40mph. I just figured it was mud in the rims. Then, a min. after getting up to 60mph, i felt some type of "bump" in the drivetrain about 3 times in 30 sec.. Me and my buddy couldnt figure out what it was. So, about 2 min. later, he asked did i take it out of 4X?(4x4 light not working).......... Nope, so i shifted out of 4x at 60 mph, slowed down to about 40, vibration still there(figured it must be mud), but now im out of 4X so, i know ive probly solved the bump we felt earlier. Back to 60. As im driving for about 5 min, the truck just dosent feel right. Seems to be rough feeling in the drivetrain. So, i slow down to about 5 mph, shift in and out of 4x, roll to the side, spin some tires to check 2wd. Get back 60, all vibration at 40 and 60 gone. Truck feels great.

The question is, could i have damaged anything by driving in 4HI for 5-10min at 60mph on a pretty straight HWY? I have not checked 4X operation since then. Thanks -Jake

Jambbii

hmmm doesnt sound right. I race in 4wd and I am around 90mph in 4wd drive with not vib at all. I woudl start at the drive shaft though to see if that is the culprit.

TxDiesel007

Probably not,

The reason im speculating you had trouble gettin out of 4Hi was because you didnt slow down early enough, Surely if you were turning out of the lease or huntin camp you noticed that it was kinda bouncy, an indicator 4x4 is on, i would say.. It has happened to me before, what i do to make sure that the 4x4 isnt engaged anymore is simply shift into it when i need, it, when i dont, i stop, get my foot off the throttle, tranny in neutral, take it out, and dab the throttle a couple of times, then i drive forward and it seems to work, Apparently if you get it out of 4 wheel drive, it wont disengage till you get your foot off the throttle, at least ive been told, ive been tryin this before, and it seems to work fairly well, so i just let it be.. AS far as damaging parts, i dont think anything got damaged, the transfer case is tough enough to take a little abuse here and there, your u joints might be bad, or you might have some play in the axle, not very likely but it is possible...

TxDiesel007

DZLPWR

Im not realy too worried about the vibration being in 4x4 caused since i never use it on pavement. And it realy only vibrated at 40mph. But, i was wondering, does the front drive shaft turn all of the time? Or just in 4x4?

cumminsdriver635

Front driveshaft ONLY turns when in 4x4

Eric

TxDiesel007

Vaccum actuator,

only engages in 4x4 when the vaccums engage the front axle to lock, very similar to chevy operation...

TxDiesel007

DZLPWR

Okay. Well i guess the shaft may be unbalanced because it is sort of rusty. Maybe the joints are bad? Is it realy something to go-ahead and fix or just let it be since i only use it as reasonalble speeds off-road or in snow?

TxDiesel007

Depends on your comfort level,

Usually, i like to check and fix all U joints as soon as i get a new vehicle, but the previous owner of this truck gave it the royal treatment before i got it, i have reciepts and all, I was having a problem with my 4x4, it would take forever to engage, but i just replaced the vaccum hoses and it worked lik new... I guess a good baseline would be, if you use the 4 wheel drive that often, fix it, but since you are at moderate speeds, and use it with care, let it be, if it gets worse, then jump on it, dont be like me and wait till somethin breaks... Because my experience has told me, one thing breaks, and others are sure to follow and quick.. Best of luck and hope all works out well..

TxDiesel007

MikeR

You could have a front axle U joint going bad.

DZLPWR

Okay. Thanks for the info