Mustang_Sally01

My 2001 Cobra has been having this issue for a while. As I get up to 70-75, there is a vibration when I take my foot off the gas, and when I put it back on. When under power, there is no vibration. When coasting, no vibration. When I hit 80, it's vibrating hard enough to shake the mirrors. I don't dare take her any faster.

New brakes and tires last year, just turned over 100,000 miles.

Any clues as to what this could be?

Thanks in advance

Z28KLR

Engine or trans mount maybe? I was originally thinking tires or driveshaft balancing issue but since it doesn't do it when applying throttle then I think that kinda maybe rules those out for now.

Mustang_Sally01

Thanks, I was told by a mechanic that it could be the u joint. I just don't want to get 'taken for a ride' by the local garages.

Z28KLR

Definitely could be U-joint, but I would think that it would cause the vibration at speed regardless of whether or not you were into the throttle. Would be worth your while to inspect.

It's an inexpensive and easy part to replace if you wanna do it yourself. A set of snap ring pliers will make it much easier, but I've fought my way through removing snap rings with needlenose pliers and a flat screwdriver before.

DRAGUL

I fought the same problem on my 01. In my case I finally found the tail shaft bushing on the transmission was worn causing the vibration.

fastbackford351

If you're going to replace your u-joints yourself, keep an eye on the needle bearings.

When my brother and I were much younger we were replacing the u-joints in the fastback and were playing hell trying to get one of the caps squished down far enough to put the snap ring back in. Being the geniuses we were we figured that we needed more oomph on the situation so my brother got a 4' cheater bar and put it over the handle on Pops vise and proceeded to squish the hell out of it until, BAM! He busted dads vise in two. Man, was he pissed. Several lessons were learned that day.

Found out that one of the needle bearings had fallen out of place and was keeping the cap from fitting properly.

WhiteFoxGT

Could be u-joint, d-shaft loose in tail shaft like mentioned above, or a bad cv axle if your car still has the irs in the rear

Mustang_Sally01

Thanks for the replies!

Had the oil changed on Friday, and the 'mechanic' checked the drive shaft, the u joints and found nothing worn. I got under the car while it was up, and the u joints seem fine. Couldn't see anything unusual. It was very clean, normal wear and tear considering some of those 100k miles were very hard miles at the track.

Tail shaft bushing sounds possible, also cv axle. Problem now is I need to find a good mechanic, the oil-changer guys I don't trust.

Looks like I'll be on the hunt for a new Mustang Man lol.

WhiteFoxGT

where at in maryland are you? I live in DE literally 300ft from the MD line on rt40, Id happily be your mustang guy if its feasible distance

wsherrard

Beware of strangers claiming to be Mustang guys