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Drive shaft weight
Kieran - 16/8/07 at 12:09 PM

Whats the purpose of the big heavy block clamped half way along my fiesta driveshaft?? Im putting the diff and shafts in the back of my car (mid engined bec chain driven diff) and the longer shaft as a (well had, i've taken it off now) big heavy block clamped to the shaft. Balance weight?? Vibration damper??

Any ideas??

Kieran

nick205 - 16/8/07 at 12:26 PM

Most FWD cars have unequal length driveshafts or to be more accurate a driveshaft extension on one side. FWD transaxles are generally bolted to the end of the engine meaning one driveshaft has to run along the back of the engine block then out to the hub. Theis extension piece is usually supported by a bearing in a carrier bolted to the back of the engine block. So the lump you refer to is probably the mounting for the bearing.

JohnN - 16/8/07 at 12:35 PM

I don't know the technical explanation, but it is some form of vibration damper. You could try the car without it and if there is no discernable vibration, chuck it away

DarrenW - 16/8/07 at 12:48 PM

On some steering systems they have a rubber joint, Toyota term is a CNI (Compound Noise Isolator). not sure if this si the same on driveshafts or not.

mcerd1 - 16/8/07 at 03:47 PM

quote:
Originally posted by Kieran
Whats the purpose of the big heavy block clamped half way along my fiesta driveshaft??

I think I know the thing that you mean

a metal disc in two halfs, clamped round 1 of the driveshafts (I can't remember if its the short or the long one)
its about 90mm dia. and 15mm to 20mm think ??
I had one of these on my mk1 fiesta too

sorry I don't know exactly what its for - but I wondered if it was possibly a weight to balance the moment of inertia of the two unequal shafts (assuming its on the short one)

-robert

[Edited on 16/8/07 by mcerd1]

NS Dev - 16/8/07 at 05:31 PM

Last reply is spot on except that it'll be on the long shaft

[Edited on 16/8/07 by NS Dev]

chriscook - 16/8/07 at 07:09 PM

Its for NVH (Noise, Vibration & Harshness) - bin it! You are building a '7'.

mcerd1 - 17/8/07 at 07:46 AM

quote:
Originally posted by NS Dev
Last reply is spot on except that it'll be on the long shaft


well that was from memory and I sold the cas nearly 4 years ago, I almost kept too it as a resto project - but kitcars are more fun

I suppose the big question about the weight is - what happens if you take it off ?? - only one way to find out

[Edited on 17/8/07 by mcerd1]