Front Driveshaft Vibration

[jdross440]

I have a vibration in the front end of my 2007 3500 dually. It appears about 55 and almost goes away by 75. It has been there for some time (Probably 70K miles at least). I have had all 6 tires balanced several times. Rotating doesn't change location. I took it to the 4 wheel drive shop to get new gears put in (going from 3.73 to 4.10 for towing). They noticed the vibration and have been trying for a week to find the cause and cure it. All the u-joints were replaced 15K miles ago (both front and rear driveshafts) with no change. They took the front shaft out and the vibration is gone. They sent it out and had it balanced with no change. They put it up on jack stands and ran it that way and vibration is there. They noticed the yoke on the front differential had some run-out in it so replaced that with a little change.
Is this vibration normal for these trucks?

 

[Motorhead]

You should not feel any vibration. Did they replace the Cardan joint? Apparently there is a centering ball that goes bad too.

https://www.youtube.com/watch?v=Bou5VwXPR_0

 

[ranger 393]

Have they tried adjusting the caster on the axle?

 

[AEdelheit]

Should not have any vibration but if there is excessive castor that puts the front flange at a steeper angle and can cause vibrations.

 

[jdross440]

The front end alignment is good. I had it checked 10K miles ago. The centering ball was changed when the u-joints were replaced and the driveshaft shop said it was good as they checked it before balancing. If you take the shaft out, the vibration goes away. It's strange to me why it shows up at about 55 and mostly goes away near 75. I just talked to them and they are rechecking the setup on the new gears.

 

[Motorhead]

What would be nice would be if you knew someone that had a truck with the same drive line. Try the other drive line and see if the vibration persists. Could there be any issues with the transfer case?
Only other suggestion would be to remove the front drive shaft, put the truck in 4 high so the front drive of the transfer case is turning and see if you have the vibration.

 

[sag2]

Have they checked the run out of the front shaft with it installed? It has to be less than .015 or it can vibrate. I have balanced quite a few on the truck with hose clamps. If you search you will find detailed instructions I posted several times.

 

[Motorhead]

sag2, Good point. Put the truck SAFELY on JACK STANDS so the load of the truck is on the axles and the suspension compressed. Set up a dial indicator on the front drive line, turn it and see if it has excessive run-out.

 

[jdross440]

I went and drove the truck. The vibration I had before the gear change was more like a tire out of balance. Could barely feel it in drivers seat but could feel more in passenger seat. Now at 55 and above it shakes the whole truck. The mirrors shake so bad everything is a blur. They pulled the driveshaft and I drove it and it is smooth. I don't know what changing gears would do to make it shake like this and they are totally puzzled too. They specialize in 4 wheel drives. They are going to send the shaft back to the balance shop tomorrow and have them redo it. They said my shaft originally had 4 weights on it from the factory, and they weren't lined up. Like the factory did a hit and miss approach at balancing. They said if it comes to it they will build a shaft similar to what the 2016 trucks have (slip joint like the older ones and no Cardan joint). They checked the transfer case and checked for any roughness in the output bearing, run-out in the flange and for any looseness. I did bring the truck home to put miles on the gears without the shaft.

 

[Chip Hayden]

Just a shot in the dark but, I struggled with a vibration issue for a couple of years [u-joints, center bearing, etc.]. It came to a head when a shock started leaking fluid. As i replaced all four, not one of them had any resistance[dampening] left in them. Four new shocks later and not a trace of vibration[so far]. I did also buy four new track arms but have not installed them yet.

 

[Motorhead]

The weights on a drive line won't be inline with each other. Have the 4 wheel shop that did your ratio change, check the front differential yoke or plate that the pinion mounts too for straightness.

 

[jdross440]

They installed a new yoke on the differential trying to find where it's coming from. Like I said, it was a very small vibration before changing the gears, like a tire out of balance. It seems to me it would be the new gears/bearings causing it since that's the only change made. But with the driveshaft unbolted (or totally removed) from differential there is no vibration. If you put the truck up on 4 jack stands, the vibration is there just like when driving it.

 

[sag2]

Are they sure the ratios are the same front and rear? Just a long shot. Putting it in 4H would prove that out pretty quickly.

 

[GrantP]

4.10's are going to make that front driveshaft spin faster at a given speed vs 3.73's, that may be why you've noticed a difference in vibration after the swap. Is the suspension stock? There should be near zero angle between the front pinion and driveshaft in a cardan style setup. Since it quits vibrating when the front DS is removed I think I'd just send it off to a reputable DS shop like Tom Woods to have it checked. I've had good luck with them (and some horrible experiences with some others). It sounds like your local shop is just guessing at this point.

 

[seafish]

First step would be to get the DS inspected and balanced at a reputable shop and then reinstall and see if the problem goes away. That being said, if it is not a huge vibe, it is possible that a balancing ring from Balance Masters might fix it--

http://balancemasters.com/driveshafts/index.html

http://store.balancemasters.com/osC...th=28&osCsid=ec086d9726923a6a224b9b207d44ad8f

 

[jdross440]

We have a shop that specializes in balancing DS. That's where they sent it. They said that Dodge front DS are bad to get out of balance when changing u-joints. It was out of balance. The vibration went from one I could feel slightly in driver side to shaking the whole truck when they changed the gears. It does it whether you are driving it our have the whole truck on jack stands. They are going to send the shaft back to the balance shop today and have them recheck it.

 

[jdross440]

They sent the driveshaft to a shop here that specializes in balancing driveshafts. They checked all u-joints and center ball. They checked the driveshaft for straightness. Then they balanced it. It was quite a bit out. The shop put it back in and no change. Still vibrates violently from about 55 mph. This vibration wasn't there until they changed the ring and pinion. I am now driving the truck without the DS while they are trying to figure out what to do next (and this lets me put the break-in miles on the gears and bearings). They do plan on sending it back to the driveshaft shop and have them strip all weights off and re-balance.

 

[lpennock]

have you checked the u-joint angle? Anything over about 3 degrees is going to vibrate.

 

[jdross440]

The truck is stock height. Nothing has changed except the gears.

 

[AEdelheit]

Pinion angle is actually dictated by castor so even at stock height if you have too much castor it can cause drive line vibrations, FYI.