Lately my truck has developed a vibration at 40mph, it goes away then comes back at 65-75 mph.
So far I've replaced the rear tires and rebalanced them since.
Replaced all three u joints and carrier bearing.
New front rotors.
New front wheel bearings.

Vibration is still there...

Front tires look good, normal wear.
I don't feel a shake or shimmy in the wheel, so I'm thinking driveline.

While the drive shaft was out I checked the pinion for play. It was tight...
Rubber vibration ring on rear drive shaft is tight also.

This is driving me nuts, mirrors, cup holder, pass seat all shake going down the road and I cannot figure this out.

Do you think if I put the rear up on jack stands and carfully take it up to 40 mph I would be able to visually find an out of balance driveline?

 

Frank, does the vibration occur when towing, unloaded or both?

We had a bad vibration issue with one of our work trucks and it turned out that both inner rear wheels were bent. It took two different visits to the tire shop to locate the problem.

 

Frank have you check the phase alignment on the drive shaft. If the phasing is off it will cause vibrations at different speeds depending how far it is out of phase.

 

Greg, I don't feel it with my 5'r in tow, but I did feel it with a bumper pull.
It's worth looking into, plus My boss just replaced his F350 wheels with aftermarkets. Maybe I can score the rear aluminums from him to replace my inner steels.


Bob, everything is in phase. Maybe I'll try a 180 and see if anything changes.

 

Isn't it a NO NO to run a mix of steel and aluminum rims together on a dually?

 

clem,
Are duallys come factory with steel inner rims and aluminum outters.

 

I have been told by experts that a torque converter can give the symptoms you describe.

 

Bump.
I've been trying to track down a similar issue with my truck. Nasty vibration from 30-38. Then back at 60-65. I've rotated then swapped wheels/tires with a spare set (all 4) with no help. I'll be replacing the center support bearing tonight.

 

I went thru this very thing this past weekend. Weekend before last i towed a gooseneck with load and noticed a vibration. Thought it was ujoints, and since ive got over 250k on the gal, maybe a carrier bearing. Bought 3 ujoints and a carrier bearing on Saturday and decided to get dirty. After inspection Im confident it was the bearing that was my original culprit. After reassembly, went for a test drive and notice a vibration at about 40 and got worse as my speed increased. Drove me nuts. Yesterday I decided the only thing that could have been different was when i pulled the yoke to change the carrier. When reassembling everything back together under the truck on Sat i noticed that it didnt correctly all line back up, it was ever so slightly off, but i didnt think anything of it, thought that maybe the truck rolled or something. But afterward when i had the vibrations, I wondered if the balance could be messed up with flipping the yoke 180*. What i learned was that by flipping the yoke, it is not an identical flip. What i mean is when i had the vibration my two yokes on the front shaft were in line with each other, when flipping 180 they were ever so slightely out of alignment. I rotated over one spline, ever so slightly out in the other direction, went back and forth and flipped a few times to verify, then realized it was my own dumb@$$ fault for not marking it when taking apart. But after reinstalling in the ever so slightly off position my vibration went away. After doing this i helped a friend haul some 5th wheel rvs back to his shop from an rv show and no vibrations. So I would suggest looking to see how the yoke is lined back up after the carrier bearing installation. I hope this is your issue as well as this was easy and not something more involved.

 

If it doesn't do it with the 5ver on maybe it's a driveline angle problem that can be solved with shims at the center carrier bearing , just another idea did you check your exhaust to make sure there is no contact anywhere ? Also I don't think the studs are long enough to run aluminum inner and outers thats why there is a steel inside wheel.

 

This.

Also, weird that the vibration doesn't happen at harmonic speed intervals (i.e. 35 and 70, 30 and 60, etc.). They usually do.

I had one at exactly 23 and 46 mph after new u-joints, after everyone with any say in the matter swore that my driveshaft didn't need to be balanced. A couple big hose clamps near the front of the rear shaft slowly rotated around until everything was smooth proved otherwise. I still get a little hum at 70 (3 x 23 = 69), but not enough to probably warrant further tweaking.

I haven't had it to the shop yet to get it officially balanced. Brian thought my redneck engineering a bit strange when he was dropping parts to pull my tranny last month.

Also, even with new(ish) u-joints, don't discount a bearing failure on one that might be throwing it just off balance.

 

Damon I'll be pulling the shafts this week sometime. I marked everything before replacing the u joints etc, but I had quite a few transmissions in and out of my truck so there is really good possibility that something wasn't put back together right at some point.

1996pwrstrk, I've also come across the same solution while researching this issue. I may try a small shim on the carrier bearing if my shaft alignment is correct. It's worth a try at this point.
Also Richard (Deluxe06) has four stock aluminums on the rear of his truck. I think the studs are just long enough.
MTalley, I'll check the joints while the shaft is off. I did notice a very small amount of play on the rear u joint. Not side to side, but almost like one or both of the caps aren't seated. I removed the clips and seated the caps with a socket but it didn't seem to help.
I have read about a round shim that can be placed inside the bearing cup to stop that play, so I guess its something to double check. I love your hose clamp idea BTW.

 

Been going through this same thing! I have a manual trany I keep noticing the gear shifter would move right to left while driving and hitting bumps. So I figured I would replace the trany mount. When I compared the new one with the old one the new mount was about a 1/4" taller than the old mount and the rubber was stiffer. Took a lot more vibration out of the ride. It is about 90% cured from what I have done. I will be checking the motor mounts this weekend.

 

As for the shim you refer to putting into the ujoint bearing cap, i had a similar issue on my jeep a few years back. Took some shears and trimmed out a piece to fit from a soda can. Work perfectly.

EDIT: I reread your post and you mention inside the bearing cups, i was referring to the yoke fit of the back ujoint, if it seems loose, you can shim with a soda can, fyi.

 

(HI-JACK ALERT!!!)


The drive-shafts were marked and reassembled exactly as they were.
We replaced the center support bearing and the u-joints. The center support bearing (isolator) was definitely worn, and the u-joints were ready for replacement. Vibration from 30-38 is gone.

But it comes on STRONG from 47+ We re-balanced the wheels with no change. Then we ran the truck up to speed with the rear end in the air - the vibration is extremely noticeably. We shimmed the carrier bearing about 3/8" with no change. We're going to try to 180 the drive-shafts tonight.