guys i'll tell u a story of a problem happening in my car(fiat 127 MK3 903cc) since the last 5 months! and i really need ur help!

5 months ago the car suddenly started to shake at high speeds (100-120km/h)...i expected it was wheel balance and alignment....but i was intending to change the original wheels with new alloy ones with wider tires...so no need for balancing the original wheels now...a week after i installed the new shoes ...and the shaking was still present even after balancing all the 4 wheels and alignment of them for 2 times!!

i did every thing u could imagine to eliminate this shaking but nothing happenned:
1-changed front discs and pads
2-changed the long drive shaft, as it was bent( i thought this would be the solution)
3-checked the suspension and everything works fine.
4- for experiment i did the following:
i raised the front of the car and ran it on 120 km/h the shaking was present..
i removed the wheels and ran it again the shaking was still present but very weak..

i drove on a high way till i reached the shaky speed, disengaged the gearbox and switched the engine off...it was still present!!!

knowing that the steering wheel is shaking insanily as well during the shaking of the car..it is something related to the drive line but i dont know what it is...
sorry for talking so much and not being very well organised..
im in favor that some of u guys may have faced this problem before or could know the possible solution fo it..
thanks in advance

Since you have eliminated nearly all the usual culprits I'd say it's something suspension/steering related i.e. something loose or missing i.e. fallen off or your driving on the cats eyes just joking!

Liam

is the weight on the long driveshaft?
how did the D/shaft get bent?
possible damage to the gearbox/shaft mount or bent wishbone

How did you drive without wheels?

Maybe you buckled your wheels or they need balancing.

If you can borrow a set of four wheels you could try changing them all and see if your shaking goes away.

Trancendental said:

How did you drive without wheels?

Maybe you buckled your wheels or they need balancing.

If you can borrow a set of four wheels you could try changing them all and see if your shaking goes away.

Click to expand...

it was on stands

custard boy said:

it was on stands

Click to expand...

Ah, when he said raised I thought he meant suspension

Could still be the wheels though.

Trancendental said:

If you can borrow a set of four wheels you could try changing them all and see if your shaking goes away.

Click to expand...

the problem is that the shaking was in my stock wheel/tyres..and now the same shaking in my new wheels and tyres!!

im thinking of the wheel bearing,..could it be?

could be but i would expect noise as well.

try rear trailing arm bushes

I had a similar 'insane shaking' when I had an Uno with a severely damaged tripode joint (inner driveshaft joint). It was missing all the needle rollers and two of the rings!

I suggest you pull the other driveshaft and inspect the tripode joint (runs in the differential).

-Alex

well, i think im going to inspect it myself ..as i just recieved the haynes manual...but im afraid i could not bring it back together ....i'll read in the manual and see the degree of its difficultiness...other wise...im going to swap the engine and gearbox for 1.3 ones..cause they done over 325000km...and never been overhauled or opened before. exept for a head gasket change and clutch ....so i think it is very enough for them...

Let us know what the problem was so we can suggest it to others who have similar problems

yea yea i'll do so...just waiting to finish my final exams ...first thing i'll do is change 2 front wheel bearnings...and let us see...

check tie rods, axle bearings, wheel bearings

I gonna go out on a limb here and say it's your clutch. Had an Uno which had a clutch go slightly out of alignment and shook the hell out of the car. It took a long time to dianose so thats why I'm telling you.

Scott.

if it still happens when the car is in neutral with the clutch pedel pressed at speed it cant be the clutch, it could be the gearbox, or a driveshaft, or a cv joint. thats the parts it is most likely to be in. since you had a bent driveshaft i would guess the gearbox has been damaged from the strain of an unbalanced driveshaft rotating. the force an unbalanced or bent driveshaft creates at speed is a lot more than you'd think. it can easily damage the gearbox.