Help. Cyclic driveline vibration.

[Wertles]

2006 3500 SRW Mega Cab 4X4. 90,000 miles. Bilstein shocks/struts. 2008 steering update 15,000 miles ago. Stock rims, with fairly new tires (Kelly TSR's with 5000 miles). Tires balanced last week, 4 wheel alignment by dealer as well.



At 60 mph and above, I get this very slight, cyclical vibration. I can see it in the rear view mirror as the headlights fron cars goes blurry then clear again and I can feel it in my butt. It "feels" like it is coming from behind the drivers seat but not certain. It is about 2 seconds on then two seconds off. I have noticed this just recently as I haven't been towing and it did it nonstop today on out 300 mile trip. I can't figure for the life of me where to even start looking. Center support bearing, exhaust drone, u joints, wheel bearings???

 

[NIsaacs]

I would say a u-joint. To make sure it is drive train related, in neutral, not park, rev the rpm's up real slow and check for engine vibration.

Nick

 

[JR]

Possibly carrier bearing / ujoint. Generally when something in the driveshaft goes, it gets worse as you put the driveshaft under more load (more throttle).

 

[HBarlow]

Kelly's are not great tires and I have no idea what the tread pattern is on the ones you have. You stated they've got 5000 miles on them. When did the cyclic resonance begin?

 

[Wertles]

It was present with my 19. 5's as well. It is just more noticeable now because these are quieter and softer than the 19. 5's. this is just so odd because it is not a constant vibration at a certain speed or load. It is like someone is turning a rheostat on and off every 2 seconds.

 

[HBarlow]

It's a resonance. You might try having the driveshafts balanced by a good driveline shop. Inspect all the u joints while the shafts are out.

 

[Mark31]

It's a resonance. You might try having the driveshafts balanced by a good driveline shop. Inspect all the u joints while the shafts are out.

I also have picked up a resonance. U joints looked good when shaft was just out. Wonder if the Balance Masters drive shaft balancers work and might be a solution to our problem?

 

[Wingate]

if you feel it in the seat and see it in the mirror, its most likely a driveline issue... To completely rule out the tires/wheels, swap the fronts and backs. . If the issue goes away and/or starts appearing in the steering wheel, then you have a tire issue.
that being said, Some things you can do include removing the front driveshaft from the transfer case to front differential. . That should isolate the driveline and front diff... If the ujoints are stock, while the driveline is out, disassemble and inspect. . Also check the pinion bearing while the driveline is out. .

 

[g_dog1]

The fact that it is cyclic is very strange... . If it comes and goes, maybe the AC compressor engages then dissengages, and the compressor is screwed. Maybe the Torque converter is locking then unlocking. Maybe you have an exhaust brake that kick on and off. I was also thinking a rad fan that is faulty by engaging and disengaging. When the vibration goes away for 2 second, does it dissapear instantly, or does it fade away? If your answer is "intantly" I would say it might be one of these things. If the vibriation fades in and out, maybe something is vibratint with a forced frequency... like water in a driveshaft and sloshing around.

 

[Wertles]

This is definitely not a compressor switching on/off. It's like your 4 year old found out how to work the dining room lights dimmer knob. It fades off and on predictably. I will shift into neutral at 70 next time out and see if it continues.

 

[JFought]

i notice that when i get close to time to rotate the tires i get exactly what he describes. however my frt tires are always a little cupped from fast stops, an lots of cit driving with trailers and lots of turns.

Usually after rotating the tires the flat rears (mover to the frt) pretty much make the noise go away-barring the normal noise from nit to terra graplers at 70mph road wine

 

[Wertles]

Well I just got back from another drive. I put it in neutral at 68 mph and the vibration goes away. I am starting to think it may be a wierd exhaust drone. I can't replicate it at 2100 rpm in 3rd or at 68 mph in 3rd either. Maybe it's time to look at the harmonic damper.

 

[B.G. Smith]

When you go into neutral the angle of the differential in relation to the support bearing on the drive shaft changes, bet it,s drive line related, maybe a "U" joiont getting stiff or could be the splines binding at the slip joint. bg

 

[sag2]

Search on drive line vibration and you should find some of my posts detailing this drone/vibration. It is normally caused by the intersection of two vibrations, one being the 3rd order engine firing frequency (normal six cylinder engine firing pulses) in combination with a first order drive line vibration. You need to go back to what you did to break the truck. If it was never there and just appeared it is most likely caused by someone pulling a drive line and not replacing it in exactly the same position. If that isn't it, the motor mounts, exhaust hangers, u-joints, and drive line balance are most likely the source. Once you have it, it can be very difficult to isolate and correct. Replacing lots of parts is usually a waste of time and money.

 

[ColemanR]

I would pull the front driveline then go drive your truck. I'm going to bet the vibe will be gone. Which means you have a bad joint. I chased a vibe around could not find it. I kept checking with a temp gun nothing seemed abnormal till the vibe went crazy I changed lanes on the freeway cause I thought it was the road I didnt get to the shoulder fast enough. 7 k later I was back on the road yes I said 7k driveline came loose tore the transfercase out of the truck. The other thought is if the rear driveline has been out of the truck unbolt it and turn it 90 degrees and reinstall do this till vibe is gone. Good Luck Randy

 

[avidfan]

I had the same problem. It is the confounded American Axle driveshafts. American Axle balances the driveshafts AFTER the slip yoke/balance & differential flange are installed. The U-joint caps are held in place with injected neoprene (or nylon). What this means is you will probably have to rebalance your driveshafts after you change your u-joints. My first u-joint went out at 48,000 miles. The dry u-joint caused a bad vibration in the drivetrain. I had the u-joints replaced by a reputable driveline shop in Lexington, KY. The problem is the shop did not have a driveshaft balancer. The shop manager assured me that he measures the u-joints with a very accurate dial caliper before he replace them and puts the new u-joints in with the exact same location as the old. Wrong. The truck vibrated as soon as I got it back. It was not as bad as the dry u-joint but still bad enough to drive you nuts at highway speed. I took the drive shaft out and took it to Republic Diesel in Lexington, KY. They have a driveshaft balancer. After 2 tries at balancing, it still vibrated, just at different rpm/mph. At this point I mistaking thought it was something else. Maybe the front driveshaft had bad u-joints as well and they were vibrating? I had the front u-joints replaced. Still vibrated. Now I am getting mad. I had both drive shafts rebalanced by a heavy diesel driveline shop in Cincinatti. Still vibrated. I had the driveshaft rebalanced by Joint Clutch & gear in Detroit. Still vibrated. OK. Now I removed the front driveshaft: truck still vibrates. I order a custom made aluminum drive shaft from Drive Shaft Super Store in Phoenix, AZ.

The vibration stopped. When I re-installed the front drive shaft the vibration resumed. Yes, both driveshafts were now out of balance. After much head scratching, cussing, searching, etc. , etc. , etc. I was recommended to Jim's Drivetrain Specialities in Garden City, ID (yes, thats IDAHO). Jim explained to me that none of the heavy diesel drivetrain shops have the proper differential flanges to mate the drive shaft into the balancing machine. He has custom made his own. I sent him my front driveshaft. He replaced the u-joints (again) and had to cut and re-weld the shaft to the slip yoke collar. If it is more than . 060" off center it is difficult to balance: mine was over . 060" off. Sloppy American Axle junk. When I got it back from Jim it worked perfectly. NO VIBRATION!!! Jim explained to me that I did not need a new rear aluminum driveshaft, it was just that no one had the proper balancer with adapters to do it the right way. He has balanced hundreds of driveshafts for the local Dodge dealer. Other have told me they have replaced their u-joints with no problem. Maybe. Maybe not. I have a buddy that replaced his u-joints and his truck now vibrates. He refuses to believe the aforementioned is the problem. I read countless articles on "Third order vibrations", out of sync drive line components, improper driveline angles, etc. I was just the an improperly balanced driveshaft. We do not live in a perfect world. While American Axle has it's faults, it is still better than the old Dana 70: it is stronger. I burned up the inside carrier bearing on my 95 Dodge diesel and had to replace the whole rear end. (At least with the Dana you do not have to rebalance the driveshaft after replacing the u-joints!)



Jim's Drive Train Specialities

113 E. 41st Street

Garden City, ID 83714

208-384-0477



P. S. The American Axle front hubs on you 4 wheel drive are also generic junk. They last about 100K. Lube them through the anti lock pick sensor hole in the top of the spindle and they will last. The stock Dodge front ball joints are good for about 100K. I replaced mine with Dyna Trac. Much better. Moogs are OK, but not as good as the Dyna's. O'Reilly's will give you lifetime warranty on the Moog's, but you have to replace them more often than the Dyna's. If you have a "death wobble" in your front end it is most likely the ball joints. Other widly advertised remedies do not permanently solve the problem.



John S.

2006 2500 Qaud Cab

1995 3500 Chassis Cab w/flat bed

 

[Alan Reagan]

I also have picked up a resonance. U joints looked good when shaft was just out. Wonder if the Balance Masters drive shaft balancers work and might be a solution to our problem?

I had a vibration at 70. I rotated the drive shaft on the rear 180 degrees and that helped significantly. I found when I did that that there is a little tolerance in the yoke, so I aligned the shaft and rear yoke and that took a lot of it out. Then I added the balance master to the rear and the problem is solved. Mine would shake the passenger seat and irritate the devil out of me on long drives. Also, I have the Balance Masters on all four wheels now and it has made a significant difference. If you added them to the wheels, make sure you pull off the wheel weights. I didn't and it shook the truck pretty bad. Don't bother with a Balance Master on the front shaft. I tried to do that and it won't fit over the u-joints.