Installed Shaftmaster Aluminum Driveshaft, Serious Vibration Problem

[Digital_Synapse]

wow

 

[COYO TT]

My shaftmasters doesnt vibrate, turns out it was an exhaust hanger. I think yours must have gotten dropped during shipping

 

[RedMustang]

keep us posted

 

[rsb5772]

Mine arrived today. I won't have a chance to install it until Sunday at the earliest, but I'll let y'all know how it works out.

 

[levelbelow2000]

PST is who we use for our driveshafts. We have used them for the last 7-8 years.

They will take care of you, and you will not be let down with what they offer.

Calvin, I hope you get this resolved.

I shipped my Shaftmaster driveshaft back today. Im going to go with the PST driveshaft, I talked to them today. I have to take a measurement then going to get it ordered up.

Kelly, can u pm me a price on the BMR driveshaft safety loop. Thanks

 

[GeorgeInNePa]

I shipped my Shaftmaster driveshaft back today. Im going to go with the PST driveshaft, I talked to them today. I have to take a measurement then going to get it ordered up.

Kelly, can u pm me a price on the BMR driveshaft safety loop. Thanks

Aluminum or CF?

 

[levelbelow2000]

Aluminum or CF?

Im going with the Aluminum one. The CF one is big money.

 

[Mike@PowerHouse]

Not sure I buy this....

I personally feel it has more to do with the slip yoke design vs. a CV joint design.

Pinion angle is the key and may be beneficial to set it properly for this piece to work as intended.

Im not trying to sell it, but it is basic engineering math.

Low critcal speeds are cause by a combination of the following:
Length of tube, the longer the lower the c.s.
Diameter of tube, The smaller dia the lower the c.s.
Weight of material, The heavier the the lower the c.s
Tube wall thickness, The thinner the lower the c.s.

I agree that pinion angle is a factor but its not the exact cause. you'll likely not run into a driveline angle issue with a mostly stock arrangement car.

Now as far as the slip yoke goes, We use a spicer brand slip yoke. These slip yokes are similar to what is found on hundreds of thousands of production vehicles across the country. Assuming that they are using the same slip yoke as our 05-09 shaft I will have to say that it is not the slip yoke.

 

[908ssp]

I ordered my PST 3.5" aluminum drive shaft yesterday morning. I talked to the engineer there and he confirmed my anyalsis the combination of having the differential and the engine not parrellel and the splined shaft. If there is enough play in the spline for it to move then it is possible for it to bend at the spline. Not a permanent bend just the slop on the spline not being straight so that the drive shaft is out of balance. That can change just by stopping and backing up or hitting a bump so you might have it one time and not another.

 

[wbt]

I shipped my Shaftmaster driveshaft back today. Im going to go with the PST driveshaft, I talked to them today. I have to take a measurement then going to get it ordered up.

Kelly, can u pm me a price on the BMR driveshaft safety loop. Thanks

CHE has the best D/S loop on the market IMO:

http://www.cheperformance.com/CartGenie/prod-313.htm

No drilling and a direct bolt-on.

 

[wbt]

Im not trying to sell it, but it is basic engineering math.

Low critcal speeds are cause by a combination of the following:
Length of tube, the longer the lower the c.s.
Diameter of tube, The smaller dia the lower the c.s.
Weight of material, The heavier the the lower the c.s
Tube wall thickness, The thinner the lower the c.s.

I agree that pinion angle is a factor but its not the exact cause. you'll likely not run into a driveline angle issue with a mostly stock arrangement car.

Now as far as the slip yoke goes, We use a spicer brand slip yoke. These slip yokes are similar to what is found on hundreds of thousands of production vehicles across the country. Assuming that they are using the same slip yoke as our 05-09 shaft I will have to say that it is not the slip yoke.

Bottom line is 3.5" is fine. D/S diameter is not the issue here...

 

[KJGT]

Bottom line is 3.5" is fine. D/S diameter is not the issue here...

It could be, especially with an aluminum shaft.

lot of factors involved, I kind of look at it this way though. If Ford could have figured out how to do it with a simpler and CHEAPER one piece driveshaft with no NVH issues, and they have some pretty good engineers, then it would have been done from the factory.

Has anyone broke a stock 2011 GT driveshaft yet? Just curious.

 

[wbt]

It could be, especially with an aluminum shaft.

lot of factors involved, I kind of look at it this way though. If Ford could have figured out how to do it with a simpler and CHEAPER one piece driveshaft with no NVH issues, and they have some pretty good engineers, then it would have been done from the factory.

Has anyone broke a stock 2011 GT driveshaft yet? Just curious.

You bet. The tend to fail at the CV joint and then candy cane.

Attached are pics of one off a low 12 sec. car.

 

[KJGT]

You bet. The tend to fail at the CV joint and then candy cane.

Attached are pics of one off a low 12 sec. car.

Hmm, I havent seen a 2011 break myself yet. I assume it was a stick shift car.

I seen the 2011 V6 one on the dyno explosion thread but the V6 has a different driveshaft.

I have gone 10.80s on the stocker and have no plans on changing it again after dealing with the first one piece I bought. If I was racing the car every weekend I might but i doubt I'll hit the track more than a couple times a year. I drive the car every day so no vibration is more important to me right now. I know someone makes an aftermarket 2 piece for the GT500s, not sure for the GTs, but its pricy.

I have seen a lot of stock GT500s at the track getting beat up and I never seen a driveshaft fail so I assumed they were fairly strong. Granted they are heavy and the center bearing is just another thing to eat up power..

 

[wbt]

Hmm, I havent seen a 2011 break myself yet. I assume it was a stick shift car.

I seen the 2011 V6 one on the dyno explosion thread but the V6 has a different driveshaft.

I have gone 10.80s on the stocker and have no plans on changing it again after dealing with the first one piece I bought. If I was racing the car every weekend I might but i doubt I'll hit the track more than a couple times a year. I drive the car every day so no vibration is more important to me right now. I know someone makes an aftermarket 2 piece for the GT500s, not sure for the GTs, but its pricy.

I have seen a lot of stock GT500s at the track getting beat up and I never seen a driveshaft fail so I assumed they were fairly strong. Granted they are heavy and the center bearing is just another thing to eat up power..

Yes was a stick car and for sure have more driveline shock than an auto.

I will be installing my D/S in the near future and will post if I experience any issues. I think the Shaftmaster piece is the best 1 piece alum. design on the market. If something is wrong after install I will have them send me a replacement.

 

[KJGT]

Yes was a stick car and for sure have more driveline shock than an auto.

I will be installing my D/S in the near future and will post if I experience any issues. I think the Shaftmaster piece is the best 1 piece alum. design on the market. If something is wrong after install I will have them send me a replacement.

I agree, plus some guys manual trans can tear a 9" ring and pinion and spit aftermarket chrome moly driveshafts out of fairly stock horsepower cars. Not to mention all it takes is one little ding in the tube and a driveshaft can fail. I just havent heard about a ton of failures. I can really care less about the power loss with the heavier shaft, but I also dont want to break a tailshaft on the trans or tear up the fuel tanks if the rear half lets go.

Seems like every one piece manufacture has people say they have zero vibration and others that say they vibrate. If they were 100.00 I would order one of everyone and see, but at 6-800.00 its something you would hope would work the first time..

 

[levelbelow2000]

They got back to me with what was wrong with it. They installed it on their balancer and checked the runnout and balance. Their not quite sure how it happened but the runnout at the trans. end was excessive causing an imbalance issue even at low rpm's which is very unusual. These things happen, there customer service is excellant.

 

[BMR Tech]

That is great to hear.

I assume you are getting another back, correct? Keep us updated.

 

[Mishri]

I also have a shaftmasters, but it's on my 2007, i get vibration starting at 85mph and gets pretty bad at 100mph.. so i dont go above 80 i'm removing and selling it since i'm getting a 2012 anyway.. not sure if it's a driveshaft issue or an installation issue (maybe some bolts aren't torqued tight enough?)

 

[kdanner]

FWIW, at the Texas Mile last weekend I repeatedly took a Dynotech 3.5" aluminum shaft to 8500 driveshaft RPM, no vibes even at that speed.