70 mph vibration

[JDKammin]

I bought my 05 4x4 dually about a year ago. I flew to Dallas/Ft Worth and drove it home to Iowa. I noticed it had a vibration that started at 70 mph. If I kept it just below 70 mph, the vibration was not there. After getting it home, I replaced all 6 tires, rebuilt front driveshaft, replaced RH ball joints, axle shaft joint and changed all of the fluids. I recently had a 2 week job that took me 6 hours away from home. During that trip, I realized how annoying the vibration was. I took the truck to a local HD truck repair shop to have them look at it. Since I had a rear driveshaft balance issue with my previous 04 Dodge, I was thinking the 05 had the same problem. After a test drive, the owner was leaning towards a rear driveshaft issue, too. They pulled the shaft and put it on a balancer. One u-joint was causing the indicator to move around. After that was replaced, the driveshaft ran smooth. With the shaft was reinstalled, I drove it around, but still has the vibration. The repair shop is thinking the problem is deeper in the rear axle or transfer case. He did drain and checked the rear axle oil for any filings, but did not find anything. I have rotated the two front tires to the rear, which still leaves two wheels on the rear of the truck, as I bought it. I am going to make time to replace the LH ball joints and axleshaft joint, but don't think that is the issue. Anyone have any ideas? I could swap the two non-rotated wheels to the front, try some other wheels, or pull the differential. Any help would be greatly appreciated. Thanks.

 

[RVTRKN]

I had the same issue, and the drive line shop removed one of the drive shafts to at least illuminate the front or rear causing the vibration, it turned out to be a U-joint in the rear and was relaced, even though it was under warranty. I paid for it due to being on the road and not trusting a Dealer I didn't know. Later the vibration came back just before the warranty was up, but this time I was at home and my dealer just ordered a whole new drive shaft for the rear, and problem went away.

 

[Wingate]

where do you feel the vibration? can you feel it in the steering wheel or in you seat? One thing you might do is to pull the front driveline and physically check the u-joints. . this sounds like a seized u-joint... Remember, since the front end and rear are connected by driveshafts, sometimes, a vibration that is actually coming from the front end may seem to be coming from the rear...

I have only heard of one AAM differential failure... . not saying it cant happen, just saying it would be rare.

 

[steved]

Pull the front driveshaft and see if it goes away... I had the 70mph vibes, took a set of lockout hubs to cure. Its something in the front driveline, and I convinced its the transferscase.

 

[JDKammin]

I cannot feel any vibration in the steering wheel. I think I drove the truck with the front driveshaft removed and did find a u-joint that felt a little notchy and had the complete front shaft rebuilt. I wish the shop I had it at would of replaced all of the u-joints and hanger bearing, while it was off of the truck. Thanks for the input.

 

[Hoefler]

Check the phasing in your rear drive shaft, make sure all the joints line up. If it is in phase, re-clock it 180*. Did the drive line shop balance both shafts as an assembly?? If not, find a shop that can. Also have them check for a egged tube, twisted tube, or any dents.

 

[ssanders60]

I had the 70 mph (2000-2100 rpm) vibration in my 2003 4x4, dealer blamed it on the tires, etc, you feel the slight vibration thru the accelerator and steering wheel, gave up

on it, finally at near 100,000 miles it started rattling or chirping. I took it to the dealer

and he said all of the u-joints were good, drove it another 2 weeks and entire truck started vibrating. I took it back and told them to take the front drive shaft off and examine it. The problem was not any of the ujoints, but concealed in the portion that fits next to the transfer case, specifically that portion between the two ujoints, whatever that might be called (continuous velocity ?). It was binding on every revolution. Freight, labor, and the new drive shaft was $629. 00, money well spent.

I never knew my truck could ride and drive so good.

 

[rscurtis]

Put a free-spin kit on it and it'll drive even better. You'll also save a little fuel.

 

[sag2]

First pull the front shaft to eliminate it as the source.

Next go down to Home Depot or Lowes and buy two hose clamps that fit your rear shaft near the rear axle. Usually 3 1/2- 4" diameter. Put one clamp on the rear of the rear shaft with the head of the clamp next to an existing weight (does not really matter where you start) and go drive it. I try and find two off ramps about 1 mile apart with a safe spot to pull over. Bring a piece of cardboard to lay on and a 5/16 nut driver.

You are looking for better/worse. Drive it, decide if your assometer thinks it is better or worse. Stop and move clamp 90 degrees, drive, B/W? Move 90 degrees, drive, B/W? Repeat until you have moved it three times.

Decide where it was better, then mark that spot and move the clamp 30 degrees either side of that spot and again determine B/W.

If you find the sweet spot, add a second clamp with the head in the same spot as the first. Determine B/W. It will normally be worse. Mark that sweet spot for reference and split the two clamps either side of the sweet spot until you get it better or perfect. Move them about 1" at a time from the sweet spot.

You should be able to make it considerably better or fix it completely. It helps if you have a vibration analyzer, but I have done probably hundreds of them with and dozens without, and the old assometer is a pretty good judge.

 

[Sandflea]

Another possibility is the transfer case output shaft bushing. I went through the same issues with the bad vibration: balanced the drive shaft (it was off somewhat), replaced the u joints front and rear, and still had the problem. The repair shop really did a great job in finally locating the problem. There was a very very small but noticeable wear pattern in the transfer case output shaft bushing. Once it was replaced, the 70mph vibe was gone. Don't have a clue what caused it, but if it comes back, I'll know where to look.