well today when i took the truck out on the highway, it seems to have a really bad vibration at around 120 kmh that feels pritty unsafe, what could the problems possibly be? the tires were just mounted but im taking them off at school and balancing them my self, u joints were all replaced a whew months ago with little drive time on them as well as all bearings, what elese could there be?

 

Bent or a really unbalanced rim.

 

A bent drive shaft?

 

the back drivers wheel seemed to wobble a little, drive shafts dident seem to be bent when i had it out that i could notice.

 

Hubs locked? Did you replace the 2 u-joints in the front driveshaft at the t-case ('c-v' joint, I think)?

 

Have you looked at the crankshaft harmonic balancer? A friend of mine just had this problem and fixed it by replacing this part. The rubber between the two pieces deteorated.

good luck

 

hubs werent locked and the 2 u joint closest to the transfer case have not been replaced but they are tight also, have not checked the harmonic balancer but will anyway, but it did not vibrate going slower up the hill and full out but it's just when the trucks reaches 120kmh or just up to it it will vibrate where i need to slow down, whitch is nothing wrong with that because thats not the speed limit anyway, ill look into the tires and see if i can find if the rim is bent.

 

120 kmh whats that speed in mph?? I know most tire vibrations come in around 50-60 mph and the drive line (drive shaft ect.) come in around 35-45 mph.

 

Ever been to Canada? They have road signs near the border that remind Americans that 55mph = 90 kmh

 

Nope never been there......wouldn't mind going up there some time sight seeing or something but don't plan on it in the near future.

 

Jack the rear end of your truck up and start it and put it in drive and watch the driveshaft to see if its bent, your wheel wobblin around is probably the problem

 

Could also be that the a u-bolt on the new u-joints worked loose allowing a u-joint to slide off center.

 

hmm , alright, well the trucks in the nice dry shop at school so ill do that and see where the problem is at.

 

I've got a vibration right around 48 mph, and again around 72-74 mph (right at 120kph). I know where my problem is though . Les Schwab has been doing my tires since I got the truck, and all wheels were straight when I got it, but have developed funny looking little round marks in between the lugs. Looks to me like they lugged up the wheels without lining up the dowel pin first... . Of course they won't admit to it, but they will SELL me new wheels to fix the problem. ]

I'm still watching the local wrecking yards for a set of dually 16" wheels that don't have divits in them. Thought I'd found a set on a Dodge motorhome, but they turned out to be 16.5's. Darn the luck...

 

I just went after my vibration that started at 80-90km and again at about 110-120km. At my work we have a force balancer that matches the the rim out of round to the tire out of round. Then you spin the tire to match the rim. They call this road force and is measured in lb. You can balance a tire all you want but if this measurement is high you'll still have a vibration. When I started I had 1 tire a 11lb which is good. (About 20lb and less is acceptable for this trucks) I had to reset 2 and got them under 10lb but 1 was at 45lb and could not be balanced that way. The machine measures the rim and calculates if the tire or the rim is the cause. Turns out that the tire is bad from the factory (good brand but these things happen) So I matched it up as best i could and got it down to 35lb, then I balanced it. Now its on the back and I cant feel it anymore.

If you now of a shop that can force match and balance the tire go there and if the tires are new and it finds 1 that is bad take it back. These machines don't lie and at my work we send alot of tires back.

Good luck