I have a high speed vibration that starts around 90 mph and gets worse the faster I go. So I haven't been driving that fast anymore because I don't want to damage anything. I have had two JPC driveshafts, three spyder shafts and I currently have a shaftmasters on there now. The vibration wasn't there with the factory shaft. I recently install a detriot truetrac with a new FRPP 4.10 gearset. I install all new bearings except for the axle bearings. The gears are quiet and the pattern was great, the preload was spot on. I thought it was the driveshaft originally because I got most of the vibration out of it with hose clamps on the JPC shaft. Since I sent the other JPC shaft back I got a sydershaft. I waited to install the shaft because I was going to do it all at once when I did the reared build. I have checked the pinion angle I have tried -2 and -1. The pinion angle didn't change the vibration at all. The first driveshaft from spyder was really bad at 60. The second shaft was better and the third shaft was great to 90. This lead me to think that the problem was with the driveshaft, after installing the shaftmasters driveshaft the vibration had seemed to be less but it is still there. I have checked the balance and road force variation and rotated the tires. Still no change, I inspected the axleshafts when I did the install of the rearend. But I never checked them with a straight edge. I am really at wits end here. I will be installing new axle bearing soon and checking the integrity of the axle shafts. Any suggests?

 

Wow...you have had more driveshafts than most of us have had girlfriends. Just a stupid question...Are you sure it not your wheels and tires that are the issue?? The reason I ask is because I had a set of stock wheels and tires that shimmied like a *****!! I had the car undercoated and it was on the inside of the rims which caused my vibrations...just a thought!
BTW...welcome to the forum!!
Scott

 

Is it really worth all that to have an aftermarket driveshaft? If it were me I would just put the stock shaft back in...

 

I have checked the road force variation and rotated the tires. I am starting to the think that I may have a slightly bent axle shaft.

 

I had that problem on my old gt. The bearing in the tail shaft on the trans was bad. I would put the stock shaft back in first then go from that.

 

I had no problems with the stock shaft because the stock shaft hides somethings.

 

This is Robert from Shaftmasters. I want to try and help out but I have a few questions that will help me understand what your saying. After which driveshaft did you do the ratio change? Is the vibration you are experiencing a shaking type vibration or is it harmonic(noise)?
Robert

 

Robert I have been in contact with David. I already had 4.10 gear in the car with the factory shaft. I rebuilt the rearend with a trutrac and a new FRPP gear set (4.10 with the "A" in the part number). All new bearings except for the axle bearings. The vibration is more of a humming noise, but you can still feel the vibration. The vibration seems to be there in 4th and 5th gears. The JPC shafts (I got some of the vibration out of the JPC shafts with hose clamps) and the first and second sydershaft were horrible. The third shaft from LRP was much better and the shaftmaster shaft was a small improvement.

 

Well, if you have had vibration with all of these different shafts, I would say it is not a driveshaft problem. Rule that one out.

 

I realize that now, the JPC shafts have had a long history of problems. I also reduced the vibration with hose clamps on the JPC shaft. I sent those back and already had the rearend parts waiting on installation. So I decided on using a spydershaft. The first and second shafts had bad vibraitons(60 and 90 mph), Ron changed somethings and sent the first shaft back. This one was way better but still bad at 90+, I just got fed up and order a shaftmaster shaft and there was only a small improvement. I am going to inspect the axle shafts more closely this week, when I replace the axle bearings.

 

Since the vibration you are experiencing is a harmonic vibration the only solution would be to go to the source of the harmonics which is more than likely coming from a problem in the rear-end. The big reason that the factory two-piece driveshaft was quieter than the aftermarket aluminum driveshafts you have tried is the rubber element sound deadener that is inside the OEM driveshaft. It is also the main reason why the OEM shaft weighs so much. The reason why our aluminum driveshaft transmitted less harmonic vibration for you than the other manufacturer's aluminum shafts you have tried is because in our 3.5 inch driveshaft we install a full length foam insert inside of it. The 4 inch cut-down Ranger shaft that most other manufacturer's use to make these Mustang shafts have a cardboard insert inside to try and dampen any harmonics. In our opinion the foam works better than the cardboard but also not as well as the OEM rubber element sound deadener which defeats the purpose of the aluminum driveshaft, which is mainly to reduce rotational weight. I hope you are able to find the source of the harmonics and if you need any assistance don't hesitate to call us.
Robert

 

Just this morning while driving to work, I noticed an intermittent clicking noise from the rear axle (while coasting to a stop). Which really sounds like a bad axle bearing.

 

First, welcome to the forum. You've been over on Stangnet before, right?

I'd listen to Robert, he knows what he's talking about.

 

Yes I am also over at stangnet, I figured I would use the same name.

 

Thought so..... good to have you here.

 

well Jared how'd it turn out? i already know but I'd like you to inform everyone as to what the real problem was.

 

Me too!!

 

So do tell.This guy has more driveshafts than I've had cars.

 

His last activity was on 3/10/08. I would like to know what the problem or outcome really was.
Scott

 

Well it sounds like something that Ron helped him out with


Nice avatar of your 70 Mach Scott.