1980 Euro vibrations
01-25-2005, 11:41 PM
#1
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1980 Euro vibrations
The car is a 1980 Euro 928 5 speed. 42k kilometers.
I am having some problems with vibrations from 3200 RPM and up (in 5th gear only) and need some help to know what to order to fix the beast.
The vibrations are not in the steering wheel but more ïn the seat". I have replaced the tires, had them balanced (twice) had two alignments and no success.
The items I have seen posted include:
a) motor mounts (the 80 has solid mounts with the small shcok absorbers)
b) CV halfshaft issues
c) tanny mounts
d) torque tube
My questions are how do you eliminate these short of dismantle and replacement or at least narrow down the problem.
My motor sits about 1/2 an inch lower than the crossmember and I read that on later models it should be 1/2 inch higher. The motor shocks look like they have never been replaced.
Any help is appreciated.
Thanks
Canadian in Qatar.
I am having some problems with vibrations from 3200 RPM and up (in 5th gear only) and need some help to know what to order to fix the beast.
The vibrations are not in the steering wheel but more ïn the seat". I have replaced the tires, had them balanced (twice) had two alignments and no success.
The items I have seen posted include:
a) motor mounts (the 80 has solid mounts with the small shcok absorbers)
b) CV halfshaft issues
c) tanny mounts
d) torque tube
My questions are how do you eliminate these short of dismantle and replacement or at least narrow down the problem.
My motor sits about 1/2 an inch lower than the crossmember and I read that on later models it should be 1/2 inch higher. The motor shocks look like they have never been replaced.
Any help is appreciated.
Thanks
Canadian in Qatar.
01-26-2005, 01:38 AM
#2
Drifting
"5th gear only".. that kinda rules out the torque tube, motor mounts, motor, clutch. CV joints usually make clicking or rattling noises at low speeds.
Have you checked the shocks? Improper toe in/out would also cause this type of vibration.
Have you checked the shocks? Improper toe in/out would also cause this type of vibration.
01-26-2005, 01:42 AM
#3
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i just did my mini-shocks and it smoothed things out a bit, but it was most noticeable at idle which doesn't sound like your problem. For about $70 I would still recommend it for an older car, it it a really easy job. The solid motor mounts on the old cars don't really compress so I would guess that it may be more likely something like the torque tube.
01-26-2005, 09:38 AM
#4
Supercharged
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Ok... 5th gear only at 3200 RPMs. Hmmmmm.... Let's see, that means you're going about 100-110 MPH!
My guess is that you have a bent rim, or that the place that is doing your balancing has a machine that is out of spec. Take it to a place (if you can find one in Qatar) that does "road-force balancing." This machine has a roller that imitates real road conditions. It will also measure the run-out and trueness on the rims/wheels.
How do I know? I had a similar problem - vibration showed up at about 100mph and then went awat at 110mph. Kept re-balacing the wheels to no avail. Then I discovered road-force balacing. Turned out one of the rims was not true. I now have a beautiful set of cup-wheels that are straight and true! The ride has never been so smooth!
Good luck! Let us know what you find out.
My guess is that you have a bent rim, or that the place that is doing your balancing has a machine that is out of spec. Take it to a place (if you can find one in Qatar) that does "road-force balancing." This machine has a roller that imitates real road conditions. It will also measure the run-out and trueness on the rims/wheels.
How do I know? I had a similar problem - vibration showed up at about 100mph and then went awat at 110mph. Kept re-balacing the wheels to no avail. Then I discovered road-force balacing. Turned out one of the rims was not true. I now have a beautiful set of cup-wheels that are straight and true! The ride has never been so smooth!
Good luck! Let us know what you find out.
01-26-2005, 09:50 AM
#5
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I had a similar problem with my 81s about 2.5 years ago - rebalanced all wheels several times.
My garagiste said he would try changing the fluid in the diff, he had seen this problem before. I collected the car and paid for the new fluid in the diff and it has not vibrated since. seems hard to believe but he swears that is all that he did.
Also had a friend had a similar problem with an S4 , in his case the wheel spacers were out of true. He had them trued up on a lathe and that fixed the problem.
My garagiste said he would try changing the fluid in the diff, he had seen this problem before. I collected the car and paid for the new fluid in the diff and it has not vibrated since. seems hard to believe but he swears that is all that he did.
Also had a friend had a similar problem with an S4 , in his case the wheel spacers were out of true. He had them trued up on a lathe and that fixed the problem.