Hello All,
I didn't want to jack 2hot2trot's thread, but I have a bad vibration issue in my car too. I just recently did a T5 conversion and I didn't change anything else on the car. The car does have a pretty mildly rough cam, but it never vibrated the way it does now even when I had a C4. In a nut shell, the car vibrates like hell between 2200 - 3,000 rpm with or without the clutch engaged and in all gears too. Under 2200 and above 3000 rpm, the vibrations go away. I believe it might be the POS flywheel that I bought from a "reputable" EBay race parts dealer, and was wondering if there was any way to check the flywheel without having to buy a new one.

My other guess is that it could be where the T5 shifter comes through the tunnel because it is in the shifter hole with little clearance.

Any ideas or suggestions?


Thanks

 

did you get the proper balance factor? 28oz?

If it does it dead stopped with the clutch in its not a driveline issue or trans issue.
so its correct to suspect the flywheel.

-Gun

 

Yes. I got a 28oz flywheel with a 28oz balancer.

I too think it's the flywheel, but not ready to drop the whole tranny again.... I already missed the majority of the summer cruises.

 

Does the vibration ever reoccur after 3000 is it back at 4000?

are you running a rubber or polyurethane trans mount?

 

I used my stock C4 mount on the T5 because it fit perfectly with the Ron Morris cross members that i am using and bolted right up to the t5.

The vibration is only noticeable between 2,200 and 3,000 rpm. vibration below or above that rpm level is non-existent.

I would think that if the flywheel was the issue then the vibration would get worse as rpms increase. Correct?

 

I have been battling this same vibration with my 66 after th t5 install. It is very common and i cant find a solution. I evn installed a 2nd t5 and it is still there.

 

I would think if it were a flywheel it would get increasingly worse.

Check to make sure the trans isn't touching anything like the tunnel especially where the shift housing comes into the car. If the trans touches a piece of the car it could make it feel like something were out of balance.

 

Have the same issue with a T5. I think it did it with the 4spd toploader I had installed previously. I will be interesting to see what solves it in your case.

 

mustang monthly did a real informative article on driveline and angles. Though it doesn't specifically apply to your car the information overall is relative. is the tranny mount height the same for both the C4 and T5? raising and lowering the tranny tail is going to effect the drive line angle. Also, have you lowered the car at all using mid eye or reverse eye springs. this would also change the driveshaft angle. Before you go pulling your tranny, I think you might consider taking some measurements, especially since this sounds like a T5 issue, not just your car.

 

The car vibrates in gear and out of gear and at a dead stop so it sounds like perhaps a pressure plate or flywheel imbalance or something like that.