Vibration between 50 & 70 mph

[markw24]

Just dropped mine off. first time they wanted it left there. lets see what how it goes this time. Hopefully when they call and I drive back up to test drive, it's fixed.

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[Unadilla248]

I attempted to balancing my stock shaft today with no luck, I installed one clamp at the rear of shaft same location the other members have gone with and made many small adjustments all the way around shaft and vibration only got worse no matter were I located clamp, The least vibration I felt was with no clamp at all.

 

[markw24]

I attempted to balancing my stock shaft today with no luck, I installed one clamp at the rear of shaft same location the other members have gone with and made many small adjustments all the way around shaft and vibration only got worse no matter were I located clamp, The least vibration I felt was with no clamp at all.

Perhaps you need to locate the clamp on the other end of the same shaft or on the other shaft. So with that said there are four locations that could be used to balance it out.

 

[ABS550]

Hose Clamps

I attempted to balancing my stock shaft today with no luck, I installed one clamp at the rear of shaft same location the other members have gone with and made many small adjustments all the way around shaft and vibration only got worse no matter were I located clamp, The least vibration I felt was with no clamp at all.

It is quite possible that one hose clamp is either too much weight (making it worse) or, not enough weight. (vibration still there)
This is why a second hose clamp likely needs to be used. By spreading the clamps apart or moving them together, you are able to go from effectively having zero added weight to having the weight of two hose clamps.
By your description, I would guess that one clamp is too much weight. So you need to add a second one and separate them.
(This is all supposing that DS balance is the source of your problem)

See the website links below.

http://www.demandaam.com/technical-support/aam-technical-tips/driveshaft-balancing

[ame]

Also look at posts 1767 and 1773 on this forum.

 

[speedfrk]

I attempted to balancing my stock shaft today with no luck, I installed one clamp at the rear of shaft same location the other members have gone with and made many small adjustments all the way around shaft and vibration only got worse no matter were I located clamp, The least vibration I felt was with no clamp at all.

You also should try just indexing the DS/pinion flange one bolt hole at a time and see if you can find a location that lowers or eliminates the vibration. Some guys do the 180deg position immediately but that's like playing the lottery. I don't remember how many bolts there are (6, maybe) but moving it one bolt hole at a time and noting the vib level at each location will give you good data.

 

[Unadilla248]

Thanks for all the info guys, Ran out of time today but my next attempt I will for shure try some of these different methods, What makes me think its the shaft is by adding a clamp I get the same feeling vibration just worse.

 

[Dominant1]

Mine never vibrated with stock shaft but did with aftermarket going tomorrow to get it flipped 180 degrees will report back!

****update the ds clocking fixed my dynotech ds vibration the car is perfectly smooth now at all speeds***** very happy with the results!

 

[markw24]

****update the ds clocking fixed my dynotech ds vibration the car is perfectly smooth now at all speeds***** very happy with the results!

That's great. Waiting for a report back on mine.

 

[Lo Pony]

Thanks for all the info guys, Ran out of time today but my next attempt I will for shure try some of these different methods, What makes me think its the shaft is by adding a clamp I get the same feeling vibration just worse.

That means the clamp is too heavy. FIrst, index the shaft at each bolt hole. If no improvement, add washers under the pinion flange bolts. I would choose a washer that is half the weight of the hoseclamp adjustment assembly, and move it around to each bolt.

How heavy is the hose clamp adjustment screw and assembly? You can find out for yourself by taking a hose clamp and cutting the metal band off it and weighing the "adjuster" part on a balance that will give you an accurate reading down to hundredths of a gram.

No easy way without an EVA. Sorry guys - text me if you want to work through this - I can tell you how to do it.

 

[Dominant1]

(Tip): If you guys decide to get a one piece Aluminum ds to fix your vibration issues with the stock ds, I would recommend the dynotech drive shaft for this reason. It comes with two bolts that go into the rear flange first separate from the actual mounting bolts. They are used as locating pins for the shaft to rear end connection. They are 180 degrees apart from each other which means you have a 50/50 shot of clocking it right. Mine was in the off position so it vibrated. I had it re-clocked 180 degrees and now its perfect. If you have vibration with another brand 1 piece ds that has no locating pins you have to keep turning the shaft until you get it in the perfect setting that produces no vibration. It takes alot more time to get it right!

FF to 3:23 in this video:

 

[GT Pony]

Look how sloppy the center carrier bearing rubber mount is on the OEM 2-piece driveshaft (go to time 2:55). Wondering if that contributes to the vibration problem. If the rubber is so compliant, it seems it could cause the driveshaft to go into some kind of harmonic vibration if the shaft isn't perfectly balanced.

 

[Dominant1]

There's so much rubber and movement in the stock ds it makes it susceptible to vibrations and adds to parasitic loss of power!

 

[LumenCordis]

Well just got mine documented by my lawyer's specialist. He detected vibrations from 20-85mph biggest spikes being from 40-49 and 60-65. Sitting tight and having to wait from here on, but ill update as i can.

 

[speedfrk]

(Tip): If you guys decide to get a one piece Aluminum ds to fix your vibration issues with the stock ds, I would recommend the dynotech drive shaft for this reason. It comes with two bolts that go into the rear flange first separate from the actual mounting bolts. They are used as locating pins for the shaft to rear end connection. They are 180 degrees apart from each other which means you have a 50/50 shot of clocking it right. Mine was in the off position so it vibrated. I had it re-clocked 180 degrees and now its perfect. If you have vibration with another brand 1 piece ds that has no locating pins you have to keep turning the shaft until you get it in the perfect setting that produces no vibration. It takes alot more time to get it right!

FF to 3:23 in this video:

not exactly right... you got lucky with the 180deg change but the imbalance can be at any clock angle. Could have been at 90deg or 120 and then you would have been doing the hose clamp trick too. The balance is affected by the pinion flange and gear since it is all rotating together and at the same speed. I suspect that what you ended up with is good enough for you to be happy, but with accelerometers mounted on the car, you could keep tweaking by adding weight at different clock angles until it is basically zero. This is what should be happening at the factory but obviously isn't!

 

[Dominant1]

not exactly right... you got lucky with the 180deg change but the imbalance can be at any clock angle. Could have been at 90deg or 120 and then you would have been doing the hose clamp trick too. The balance is affected by the pinion flange and gear since it is all rotating together and at the same speed. I suspect that what you ended up with is good enough for you to be happy, but with accelerometers mounted on the car, you could keep tweaking by adding weight at different clock angles until it is basically zero. This is what should be happening at the factory but obviously isn't!

I see what your saying: its not all the way perfect, but i don't feel anything at all now at any speed. That's acceptable to me..and yes i understand that its not really perfect over all until you start putting the devices on it that can locate the specific areas of imbalance and then eliminate the things you cant feel.

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