Technical Awful sound after 500 -> 650 conversion

Graabein

New member
Joined
Jul 28, 2016
Messages
10
Hi all!

I recently did a conversion from 500 cc to 650 cc on my -69 Fiat 500L.

Both engine and transmission was replaced.

At first there was a not to obvious knocking sound when I was driving. But after a while, it got really bad. I have added a link to a movie filmed inside the car when cruising with the engine off.

The sound is related to speed, and not rpm. The sound is there in all gears.

Does anybody have an idea about what this might be?

I cannot replicate the sound with the car jacked up.

Sorry about the english, I'm from Norway :)

https://dl.dropboxusercontent.com/u/152310/IMG_2178.MOV
 

fiat500

Patinated Peter
Joined
Mar 7, 2005
Messages
5,792
Location
Nairn
I would check that the 4 hub-flange bolts are tight and think, is the circlip on the end of the driveshafts? Have you possibly got a stone stuck in the area around the alloy coupling?
 

thepuddlejumper

New member
Joined
Sep 3, 2016
Messages
101
Location
Airdrie
Hi, during the conversion did you swap over the 500 drive shafts. The 500 drive shafts are I think 18 mm shorter than the 126 shaft so they must be changed over. This causes a knocking during driving as the gap between the end of the drive shaft and stub axle is almost zero. Another cause could be broken or missing springs between the shaft and stub axle allowing the shaft and axle to make contact.

Ralph
 
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