Weird viabration/jutter on take off

[Matt]

Hi,

Just purchased a fiat 126 personal 4, has not been on the road since 2003 but was in great condition, I have fixed quite a few mechanical issues from the faulty coil through to the gear selector but the only issue left that has me stumped is the weird viabration that feels rather violent only on take off, i have checked  the wheel and brakes and found no problem but not too sure about the CV and weather it would be the issue. Mostly wanting to know what you guys think or have experienced.

Cheers

[findniki]

Clutch shudder is what your experiencing.

[Gadge]

Could be caused by a worn out spigot bearing making the input shaft spin in an oval pattern. I had this happen to me on a ne of mine a few years back

[Pete126]

Few other things to check 🙂

Check the engine and gearbox mounts

With the engine cold take the fan belt off, do a few starts and see if the vibration disappears

[Matt]

Cheers for the for the suggestions,

I have checked the engine/gearbox mounts and they look OK, not amazing but look to be still doing they're job.
Doesn't feel like clutch shutter as it has more noise to it and has a more solid hit to it.
But I have managed to narrow it down to the left rear wheel/driveshaft/gearbox, so a worn out spigot bearing is looking like a culprit.
as the car is not exactly road legal looking atm I haven't taken it for a drive no longer than 100m but after initial take off it mostly goes away but a clunk happens randomly thought out the drive.
one question i have is how much side ways play should the driveshaft have as the right side moves about 20mm and the left has more like 50mm of movement?

Thanks again

[Rusty's Uncle]

Hi Matt
Sounds like you should strip down and inspect the drive shaft coupling assembly on that near side. Do you have a manual to refer to ? 

[Matt]

Hi,

yes i have ordered a Haynes manual and was really hoping it would turn up this weekend but none so far.
but definitely waiting for it so i know what im going into before pulling it apart and try and locate potential worn/damaged bits.

[Rusty's Uncle]

Hi,

yes i have ordered a Haynes manual and was really hoping it would turn up this weekend but none so far.
but definitely waiting for it so i know what im going into before pulling it apart and try and locate potential worn/damaged bits.

I have got the withdrawn copies of the Haynes 500 and 126 manuals from the Rotorua library. Cost me $1 each in their book sale 
Quite surprising that they had the 126 manual as I believe that there were only 97 cars officially imported into NZ I believe.

[Matt]

so,

After this long weekend I have looked though quite a few post on this page and appears that so many people have had the exact problem I am having but once they have found the issue there is nothing to show what they found  but that aside, I now have the holy Haynes manual and without puling the motor and gearbox out as im not too keen on opening the box up i have inspected what i can and checked the bearing on the drive shaft and it is good order, I did notice there was a adjuster on it, so I did an un-kiwi like thing and read about it which the haynes manual says to send it to the local Fiat mechanic (haha). so i adjusted it and it has changed the tone of the jutter and suppressed it slightly but not to a level i find remotely comfortable.

So im thinking my new direction is to start replacing cheap easy parts i can get a hold of like the gearbox mounts and the rear engine mount as no rubber exist on the spring part and see where that gets me and then maybe the wheel bearings, but im keen on hearing any ideas that i have not covered yet that would be great.

THANKS

[Matt]

Update!!

It turns out i was the villain all this time. one of the first things i had to do was replace a rubber seal on the rear belt pulley as instructed by the previous owner. But in doing so i removed the rear engine mount and and found the rubber bushes had deteriorated and thought to myself "the spring is good enough" boy was I wrong after a few test I am pretty sure that it is the problem, so i am currently trying to locate a replacement.

 

[Rusty's Uncle]

Matt I think that you are going to have to go shopping outside of NZ for the engine mount parts. Probably somewhere like Axel Gerstl whose web site can be accessed in the reputable companies section. Probably worth looking other parts you might need if you are putting an order together. Slightly worried about your gearbox adjustment as it sounds like you have altered the setting on the diff bearings which determine the crownwheel and pinion backlash. Where are you located in NZ?

[Matt]

Hey,

Prior to making the adjustment I marked and took note of the original setting and plan to return it to that after work today. I'm located in wanganui. As for the part over talked to ant from bambina parts here and hes doing a order and is hopefully getting the part with that order which should save on that expensive shipping cost   

[Rusty's Uncle]

Hey,

Prior to making the adjustment I marked and took note of the original setting and plan to return it to that after work today. I'm located in wanganui. As for the part over talked to ant from bambina parts here and hes doing a order and is hopefully getting the part with that order which should save on that expensive shipping cost   

Hi Matt sounds like you have been very sensible there with that adjustment. If there was a lot of movement on the adjuster then it could indicate worn bearings. What was the oil level like in the gearbox?
I spent a day in Wanganui a while back. Particularly remember the river and the high street, nice place. There is an owner of a Classic Fiat 500, I think with a 650 engine, that lives there. He regularly posts on the Fiat Forum in the 500 Classic section with the user name timgarman. Could be a useful local contact for you