Drivetrain vibration

[INSANEBA]

So My car used to have a noticable vibration at about 110-125mph. You could feel it first in the shifter,, then the faster you go you could start to feel it in the floor. Since I put the 4:10's in it, its now at more like 65-70mph when it starts and is far more noticable now. I've got the clutch cable as loose as it will let me, meaning it has full pressure, the cars u joints looked brand new when I got it, the shaft isint bent, and the trans seems fine. Any ideas where to look? I wanna get this thing down the track on spray this year, but feel a lil nervous to do it like this...

[penceracing]

i had a 91 lx that did the same thing by what a friend told me at 115 to 130. he said he could feel it in the shifter. so he changed the tranny and it went away. it had the world class t-5 in it. I hate to say it but it could be your tranny. but u never know good luck with it

[mustangrfast88]

my buddy had the same problem and it was the clutch had a broken spring in it

[inferno50]

mine does it too. sounds like me and you have about the same car by all the posts. i was guessing it was my stock drivshaft out of balance but my trans is also wore out really bad. its a ford, it will grow back.

[INSANEBA]

mine does it too. sounds like me and you have about the same car by all the posts. i was guessing it was my stock drivshaft out of balance but my trans is also wore out really bad. its a ford, it will grow back.

Lol, I've been noticing that too. I dont think I'm gonna wait for it to grow, think I'm gonna pull the trans and check stuff out. Maybe toss in a centerforce and see about trying out another t5 in the process

[03z06vette]

Is the vibration there when its coasting? if not its in the trans. if not prob a tight u joint.

[Mbubby61]

I had my drive shaft balanced,, ended up being up front,, the welded about a pretty good sized weight on it. helped alot...

[INSANEBA]

Is the vibration there when its coasting? if not its in the trans. if not prob a tight u joint.

Its still tehre when you clutch it and let it coast, it goes away after the car falls back down around 60 or so. I have aanother drive shaft, think I'm gonna throw it in there and see if it makes a difference.... Cant run it down the track til this is fixed, and deffinitely cant spray it til then lol...

[mustang8998]

I would be looking at the rearend, myself (I always do, on women). I say this, because you stated that the vibration changed, after a gear swap. That leads me to believe it's in that area. Pinion, yoke, rear u-joint, etc....

[cobra429boss]

Gear could be off not calibrated right. would cause it to have a vibration

[INSANEBA]

I would be looking at the rearend, myself (I always do, on women). I say this, because you stated that the vibration changed, after a gear swap. That leads me to believe it's in that area. Pinion, yoke, rear u-joint, etc....

Thats a good idea, but it actually had it before the rear swap, but it was alot higher then. Before with the 2:73's it was at about 100mph or so, now with the 4:10's its around 65-70. Makes sense because it's winding up much higher and quicker now then with the old gears.

[03z06vette]

Gear could be off not calibrated right. would cause it to have a vibration

and mabie some noise also?

[cobra429boss]

cousin did a gear swap and it done the same thing at 65-70 mph , gear wasnt done right

[draggin50]

Thats a good idea, but it actually had it before the rear swap, but it was alot higher then. Before with the 2:73's it was at about 100mph or so, now with the 4:10's its around 65-70. Makes sense because it's winding up much higher and quicker now then with the old gears.

At those mph's was the rpm's the same?

[INSANEBA]

Seems like it might be a lil lower in the revvs now, I just figured that since it was higher before the axle, that it would drop since the drastic gear change. Did you have any vibration with this in your car Brian?

[draggin50]

Seems like it might be a lil lower in the revvs now, I just figured that since it was higher before the axle, that it would drop since the drastic gear change. Did you have any vibration with this in your car Brian?

No it was smooth as hell. It has some age to it but no noise or vibration. Have you tried to clock the driveshaft differently? I have done that before and made it smoother. I have also heard that if its the driveshaft that you can put a hose clamp on loosely and somehow that tells you if its the driveshaft. I dont know if or how it works but some old guy told me that.

[INSANEBA]

Yea I didnt think it was the axle, this was here long before the gears. I think the clamps supposed to find the off balance spot and hang out there. I'm gonna swap shafts out and see what happens next...

[draggin50]

Keep us posted on it. Id like to know.

[NXcoupe]

It's the driveshaft is out of balance or has been beat on when the u joints were installed. The reason the vibration changed mph is because with the gear you are at a higher rpm per given mph. feeling it in the floor and you'll see it in the headrests too probably. Just throw another driveshaft in it and inspect the yoke, there's your problem.

[INSANEBA]

Thanks Mike, once again providing great info! I'm gonna try another one this weekend, soon as I get this mess of a garage cleaned up lol... I'll keep ya'll posted

[mustang8998]

I'd try turning the driveshaft 1/4 turn on the yoke, too. Draggin50 suggested it, but you didn't say whether you had tried it, or not.

[draggin50]

I'd try turning the driveshaft 1/4 turn on the yoke, too. Draggin50 suggested it, but you didn't say whether you had tried it, or not.

Yeah I had tried that before and the vibration went completely away. Then I just marked the driveshaft and pinion yoke when I pulled it out again and it never came back.

[INSANEBA]

I havent tried that yet actually, it can only go 4 ways so next decent afternoon I'll give it a shot. I'll post up the results, thanks everyone...

[tangerinebeast]

does it still ahve the flange on the rear ? one thing you can do is make sure the surface of the flange is perfectly flat and the corners are not chewed up and causing the flange to not lay flat that will cause an issue. but has for turning flange on the pinion yoke i have never heard of that working but maybe i am wrong ? on our machine is doesnt affect it at all

any questions message me i work for b t shaft

[motox159]

Tangerinebeast, you wouldn't happen to be the guy I got the 90' GT roller from a few years ago????

[mustang8998]

does it still ahve the flange on the rear ? one thing you can do is make sure the surface of the flange is perfectly flat and the corners are not chewed up and causing the flange to not lay flat that will cause an issue. but has for turning flange on the pinion yoke i have never heard of that working but maybe i am wrong ? on our machine is doesnt affect it at all

any questions message me i work for b t shaft

Turn the drive shaft, 1/4 turn on the flange, not the flange on the pinion. :bigthumb