Driveline Vibrations---Possible Driveshaft Issues?

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alignman88

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It's been over 25 years since I did a lot of balancing, so take that into account. For cars I think 2.5 oz was our max and for trucks we typically considered 5 oz too much. However, deflating, breaking the bead, and turning the tire 180° is a lot of work. I think the modern strategy is just to throw more weight on it and hope it balances.

Our race trailer got a load of balancing beads in the tires, and they made a huge difference in how smooth the trailer towed empty. If it's so effective, I wonder why the industry at large hasn't adopted balancing beads.
Weight limits typically are established by the tire manufacturers as percentages of the tire weight and mass. Most shops those amounts stated are pretty standard to monitor good practices.

The balance beads/media aren’t so much balancing beads as they are a dampening agent that slightly changes the frequency of the tire at speed. Think about this, is it a harmonic balancer on the crankshaft or is it really a harmonic dampener that is balanced on a crankshaft????

Tires and suspensions share the same frequency ranges. 10-15 Hertz for both if I remember right. Disturbance + frequency of tire matches frequency of suspension you get a point of resonance letting the disturbance transfer through the chassis. We all know a vibration we feel at 60-65 mph may go away at 67 mph and up. Increase in speed changes frequency of tire, suspension frequency stays the same so no point of resonance to excite the transfer components to cabin. I’ve got spreadsheets from tire manufacturers with frequencies at different speeds. Real propeller head stuff LOL.

It all has an “effect” but balance isn’t it, more like it calms the forces so they don’t match up and get to the cabin that you feel. It’s magic dust. Put one of those tires on any computer balancer and you’ll have a wheel weight rodeo.

I think the reason it doesn’t see more traction in the market is because tire manufacturers don’t want anything inside the tire because inner liner “could” see minor degradation which is a safety hazard, as well as can you imagine how many different sized bags of media it would take for a dealer to cover all the passenger tire variations. Plus now it’s one more thing that Stumpy the tire tech could do wrong, maybe cut the bag blast the bead in place and create an air leak from media + lube between bead and rim (seen that one back in the 90’s on commercial trucks)

No doubt the trailer pulls smoother the tires are dampened slightly and not matching point of resonance with transfer components. I always balanced my trailer tires, and would easily get 100,000 miles out of them, and to boot change less light bulbs on the trailer and no fatigue cracks or failures anywhere on the trailers.

Me and my TED Talks… jeeeezzzzz what a dork.
 

Hipster

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I think the reason it doesn’t see more traction in the market is because tire manufacturers don’t want anything inside the tire because inner liner “could” see minor degradation



Me and my TED Talks… jeeeezzzzz what a dork.
I've seen it in MC tires. The "sheen" is long gone. Been through the balancer rodeo. Just really question their effectiveness.
 
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454cid

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The new zinc weights are going to be bigger in size/volume for a given mass, right? So "big weights" aren't really as big as they look, if you're used to lead.
 

Intragration

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I read the whole thing, don't know if this will be of any use. Someone mentioned drums, and this is important. I just did mine, and ended up with the wrong drums the first time. The two drum types appear outwardly almost identical, except that one has a larger hub hole, and the other a smaller one. (The only reason I can figure they did this was to differentiate between 2 1/2" and 3 1/2" brakes, maybe there are other differences, but outwardly, other than this, they seemed nearly indistinguishable to me.) If a mistake was made here, you could potentially have the bigger center hole drums with the smaller hub, which would cause them to not be hub-centric, or you might have the smaller center hole drum with the larger hub, which would also not be hub-centric, and would also force the drum further out. I think either situation could be interpreted by someone who didn't know any better (nice way of putting it) as being "close", but both would be dead wrong. This problem may not apply to inboard drums, mine are outboard.

Another thing, which I didn't see anyone mention, and may or may not apply, is hub torque. When doing seals, the axles have to come out, and the hubs are removed and reinstalled on the axle tube. A lot of the information out there seems to come CLOSE to the correct torquing procedure, but some is pretty far off, and very little seems exact. If the hubs are over- or under-torqued (or if the bearings were put in the hub in the wrong order or direction, or if the outer [?] race was inadvertently left out...you didn't mention anything about bearings so I don't know if they were touched) this MIGHT cause something like this. If anyone else totally disagrees, please correct me, I'm just throwing ideas out.
 

BBslider001

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Hey everyone, sorry I have been out of pocket. It's been a busy few days.

I hate to inform you, but my neighbor made me a fantastic offer and I accepted. It doesn't cover all of the work, but it was more than I paid originally. With all I have going on work, family, and other side gigs, I just needed my life back.

I am very very grateful for all of the help. The search begins for a replacement. You guys have seriously been great and I really do appreciate the time you took to help.

Now let the roasting begin!
 

Hipster

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Hey everyone, sorry I have been out of pocket. It's been a busy few days.

I hate to inform you, but my neighbor made me a fantastic offer and I accepted. It doesn't cover all of the work, but it was more than I paid originally. With all I have going on work, family, and other side gigs, I just needed my life back.

I am very very grateful for all of the help. The search begins for a replacement. You guys have seriously been great and I really do appreciate the time you took to help.

Now let the roasting begin
Code Red... You bailed on your unit.
 

Caman96

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Hey everyone, sorry I have been out of pocket. It's been a busy few days.

I hate to inform you, but my neighbor made me a fantastic offer and I accepted. It doesn't cover all of the work, but it was more than I paid originally. With all I have going on work, family, and other side gigs, I just needed my life back.

I am very very grateful for all of the help. The search begins for a replacement. You guys have seriously been great and I really do appreciate the time you took to help.

Now let the roasting begin!
Good luck BB! Hopefully you’ll get another. Soon.
 
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