dseid2

Has anyone else installed an aluminum driveshaft and found it was out of balance at high speed?

Installed 4.10's about a month ago and foundthat the OEM driveshaft had a light vibration at high speed so figured I would go with an aluminum driveshaft. Installed a PowerHouse 4" aluminum driveshaft Friday night and it vibrates worse than the OEM unit.Anyone know where to get a driveshaft balanced in Southern California?

On another note, has anyone found that their exhaust sounds louder after installing an aluminum driveshaft? Mine seem to be a bit louder. I was thinking that the big 4" tubemight beresonating the exhaust note.

Thanks in advance for any input.



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Mpaint99

Dont ask me why, But unbolt your driveshaft from rear axle and spin it 180 degrees and reattach it. For some reason this cures that vibration. Good luck!

sd07gt

dseid2

Mpaint99, tried the 180 flip the 90 and the 270. Unfortunately none worked.

sd07gt, the PowerHouse driveshaft comes with a flange adapter and there is no play between the flange and the bolts, although I did rotate the flange adapter this morning to see if it would make a difference.Whilethe carwas on the jack stands this morning, Istarted the car and put it into gear to observe the driveshaft’s rotation. It is hard to tell because the U-Joints may be causing some distortion,but I thinkthe end of the driveshaft, where the U-Joint mounts, is not spinning perfectly round.Like the weld at the end of the shaft was a little crooked. I have an email into CHE asking them to send me another driveshaft and RMA this one. Waiting to see what they say on Tuesday. Thanks for the lead on Morena Driveline. If CHE does not come through I will give them a call.

Much thanks to both Mpaint99 and sd07gt for the help

Best Regards

dseid2

If anyone needs a driveline shop in SoCal I found a good link.

http://www.yellowbot.com/tags/drives...0CA/page1.html

moosestang

U-joints spin in an elipse pattern, so it will not look perfectly round when spinning. If you haven't allready, try adjusting your pinion angle. Since you had the vibration with the stock driveshaft, it may not be the driveshaft at all, but rather your pinion flange or transmission output shaft. I have a vibration at 3200rpms, but not at high speeds, go figure. Mine was enough to vibrate my rearview mirror with my aftermarket shaft, but not with the stocker.

Yes my exhaust sounded louder with a 1 piece driveshaft, I believe that's the nature of the beast.

dseid2

moosetang:

Thanks for the input.

You are probably right in that the distortion I am seeing is caused by the u-jointellipse pattern. I did some more checking on the net and found that there are two types of driveshaft vibrations. One is transverse the other is torsional.

Torsional vibrations are caused by improper u-joint angles. This vibration causes a noticeable sound disturbance and occasionally transmits a mechanical shaking. These vibrations tend to be more severe at lower speeds and changes in torque load usually affect this vibration.

Transverse vibrations are caused by a driveshaft out-of-balance. This vibration emits sound waves you can hear and mechanical shaking you can feel. The force from out-of-balance increases with speed, not torque load. The best way to check for this vibration is to take the car up to operating speed, disengage the engine and check the vibration while coasting.

My symptoms are a vibration at high speed not torque load and are present when coasting, so I think it is a transverse vibration, but I have not ruled out pinion angle. I lowered the car 3 months before the 4.10's went in anddid not have a driveshaft vibration. Onlyafter the 4.10 install did I get a vibration. Still one of the options on the table right now is to add an adjustable UCA to my suspension set-up(the car already has adjustable LCA's) to fine tune the pinion angle.

Hopefully tomorrow I will find out what CHE is going to do about this problem. If CHE does not come through, I willmake an appointment with a driveline shop to bring the car in.

Thanks again.

Skarkull

Ok, here is what I know about balance, vibrations, and weight.

I know that as the weight of something goes down the easier it is to effect its balance. On some cars they put a 3-5 lb. weight behind the airbag to reduce the steering wheel vibrations, and on some cars they add weight to shifter arms on trannies to reduce vibrations and gear selector shake.

You noticed the shake before you added the aluminum drive shaft, so lets just say it isn't the problem, it just made it seem worse due to the reduced weight. With the reduced weight the % off your driveline is increases, same amount off balance, but less mass involved increases the effect. I would start with your rear end, something happened with your 4.10 install.

sd07gt

Hi there,

This is what I would do .....take the shaft to a drive line shop that works on aluminum d/s @ and has a high speed balancer....make sure the adapter plate is bolted to the drive shaft when checking the balance, see where your at if its way out a wack have it balanced @ and talk to che/ or powerhouse for a refund on your balance job ?... if it's not the shaft then you know it's you gears for sure.

you already ready have adj lca..so I wouldnt get a uca to mess with the pinion angle, plus as you throw new parts into the problem it start to get really hard to find out whats really the problem...plus you dont want to mask the problem either !

just to let you know I had the same problem you are having on my mustangs years back... I put in 4.10 gears and I had a slite vibration at high speed...ok I bought a ford racing driveshaft (aluminum)..before I put it on I took the drive shaft over to have it checked out (morena st. San Diego ....the saft was in spec so I put it on and the vibration got worse...so you always go back to the last thing you changed on your car ! yep it was the gears...so I had them redone at a highly recomended shop in S.D. and problem was gone forever

good luck !

dseid2

sd07gt:

Did just what you suggested and left my Stang with a driveline shop in Vista after work today. They are going to check the car out tomorrow. I certianly hope it is not the gears as I have had them done twice now. The second time by my local Ford dealer. We shall see.

Thanks for the advice.