Vibration

[jahcompkilla]

Im in need of some help

I have an 84 spider. I have been having a lot of problems with vibration. It comes on at around 2500 on the tach. in all gears
It feels like a side to side movement. It got bad enough that I replaced the drive line, u-joints; motor mounts transmission mounts, and still didn’t get better. So I Check my gear oil and it looked like gold paint. So I tracked down a gear box and swapped it out. Looking at the input shaft I discover that the bearing is missing some balls. So after swapping it out I has hoping that this would solve the problem but I did not
I’ve noticed that the shift lever also vibrates kind of like a pair of hair clippers. I didn’t check the clutch when I removed the transmission ... I was thinking maybe the clutch has been cracked or missing a piece. I would greatly appreciate some input

[Alex Csank]

Vibrations, huh?

Did you have your entire driveshaft (both pieces together) checked for balance?

That can make all the difference in the world!

Cheers,

[120]

the gear lever is just an indicator of movement that could be coming from anywhere. I wouldn't tear into any more components until you are sure it is not something simple.
does it vibrate with the car stooped and out of gear?
coasting?
you prolly already checked those thoughts out. but that should tell you if it is in the driveline or wheels. good luck, got to hand it to you, you have tried a lot of things already.
Bruce

[Roadtrip]

Have you checked that you don't have a bent wheel? Put the car up on securely on jackstands or a hydraulic lift and spin the wheels slowly looking for run-out. If safe and solidly secure to do so, you might even run the gear-train up and see if the vibration is still there, then take the rear wheels off and note any difference. How about the rubber dounuts (guibos) and driveshaft center support bearing/carrier? Are you sure of their integrity?

It may sound stupid, but check the exhaust system to see if it's rubbing against anything. Vibration is a funny thing . . . . sometimes it's coming from where it doesn't make intuitive sense.

Very bad move not to check the clutch while you had the transmission out anyway. Let's eliminate the easy-to-check stuff before we get into the hard stuff.

[jahcompkilla]

Well ive tried every thing I can think of and all of the thing you have mentioned.

Today I went to the local alfa shop to buy a pilot bushing and talked to one of the mechanics and he seems to think it is a pilot bushing. Im going to go for it again and pull the motor out. I have a new clutch and pressure plate and bearing from my 1750 that I havent used so if I need it I will use it. I will post when im finished ..

Thanks for all of the input
JAH

[papajam]

Is the vibration engine speed related or vehicle speed related? If it's engine related, that rules out the drive line. If it's vehicle speed related and happens in all gears, that rules out the pilot bushing which, IMO, couldn't be the cause anyway.
There's a good article on vibration here .

[Roadtrip]

Are you really really sure you've checked everything that could possibly be touching the exhaust pipe or drivetrain? I had a similar problem to that with my '74 and it was only the muffler heat shield had fallen down on the head pipes. At a specific engine rpm, the vibration would loosen your fillings. Really loud and translated into the floor and shift lever especially.

[jahcompkilla]

Hello

I want to say thanks for all of the replies. This is the best board that ive been on!!!

Im going to double check everything before I get into taking the motor out again and thanks for the article on vibration it is very interesting. I will update you guys when I start working on sunday.

Thanks again
jah

[jahcompkilla]

well ive got most of my problems taken care of but there still is a little vibration in 5th gear like a bad ujoint but ive get them and inspected the doughnut they all check out. I was thinking that it may be my rear springs are sagging they are original. Its just a thought

thanks jah

[120]

what was the cure, and what was the culprit?

Bruce

[rbitzer]

Jah,

Yeah let us know what the problem was! Welcome to the board...a few people here actually know what they're talking about too which is a plus. The rest of us pretend.....

[papajam]

Even with sagging rear springs, the suspension should still be within it's normal travel range so I don't think that the springs are the problem. Since everything is new, I'd double check that the front and rear u-joints are in phase. The potential for vibration is there if the front and rear driveshafts are off by only one spline.

[Keven]

Gotta throw my guess out there:

I think you may have a hairline crack in the driveshaft donut. Visual inspection may look normal, but under load it rears its ugly head.
Hmmmm driveshaft donuts aghhhhh(ala Homer Simpson)

Just my .00002c

[WopJob]

This is just unfair - last post in 2003 and we still don;t know what jahcompkilla fised the problem. I have the same symptoms but at 3000 RPM..

[WopJob]

Quote:

Originally Posted by WopJob This is just unfair - last post in 2003 and we still don;t know what jahcompkilla fised the problem. I have the same symptoms but at 3000 RPM..