Ford Mustang Forum banner
Status
Not open for further replies.
1 - 5 of 5 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
I think I've determined the source of the vibration, but would appreciate any confirmation or other suggestions based on your experience.

The vibration is a slight rumbling that occurs under load between 60-64mph, and also coasting out of gear from 60+ down to 40mph or so. I can feel it vibrating through the shifter, which in combination with the load vs no-load factor leads me to believe it's a drivetrain issue.

It's been present for quite a few years now and I've suspected the driveshaft from early on (but obviously haven't done anything about it yet). We had a driveshaft fabricated by a shop (in retrospect, of questionable expertise) and at the time we tried adjusting the pinion angles (rear end & transmission), thinking that might be the problem. Through many adjustments using wedge blocks on the rear axle, we were never able to eliminate the problem. We also thought it could be the rear end. Since then, an observant friend noticed that the universal yokes don't match one another from one end of the drive shaft to the other. They're about 5 degrees offset. I don't have experience to know whether or not this is a problem, but it brought into question the integrity of the driveshaft and raised suspicion that it could be the source of the vibration problem.

Again, any suggestions from your experience would be greatly appreciated!

Also, if you agree that the problem is likely the driveshaft, can I have this fixed (universal yoke removed and reattached), or is it something you have to replace? ..or should replace just to avoid another miscue?

Peace!
Nick
 

·
Registered
Joined
·
211 Posts
What you can do is take the car on the highway and pop it into neutral, if the vibration remains constant it's the drivetrain. I'm willing to bet, based on your explanation, that the driveshaft is out of balance. You can also try using a hose clamp on the driveshaft and rotating around until the vibration goes away.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #3 ·
Drt, thanks for the tips.

Yes, the vibration does remain constant in neutral rolling on the highway.

Do you think yokes not lining up is a problem in and of itself? (does my explanation of that make sense?) Or do you think that regardless of the alignment, it's simply a balancing issue that can be fixed by rebalancing?

I guess it's worth a shot... if it works it works. :)

I've assumed all along that the driveshaft was properly balanced but the yokes were just not aligned. I guess it's possible that it's just been out of balance from day 1.

Thanks,
Nick
 

·
Registered
Joined
·
211 Posts
Well, typically the yokes line up. Though with a custom built driveshaft from a less than reputable company, if they didn't take the time to line up the yokes who's to say they cared about the balance? I'd try to simply have it balanced. I'd be willing to bet that will take care of it.
 

·
Registered
Joined
·
51 Posts
the yokes of the driveshaft must line up exactly. or be in "phase" other wise you will never eliminate all vibrations. balance may well improve it but it must be in phase
gtss
 
1 - 5 of 5 Posts
Status
Not open for further replies.
Top