Propshafts

[BMG]

So there is all different lengths of prop for the various engine , gearbox and diff options, but is this achieved by by both parts being unique or is one half a common part ?
Thanks

[Brianmoooore]

The rear sections of of E30 propshafts are all the same length, but the front and rear parts are balanced as one, so if you change the front half for another one, the assembly will need balancing.
The balance needs to be accurate, because of the design of the centre bearing mount.

[BMG]

Thanks for the answer. I suspected the rear half would a common part. Any chance the M3 front half is shared with anything else ? I'm guessing not as the complete prop part number is saying M3's only.

[Brianmoooore]

M3 prop. will be unique, if for no other reason than it uses a larger guibo than other E30s.

[BMG]

Thanks

[Yeti]

but if you get just the front there are white dots onm the shafts to keep them in sync and balanced so just line the dots up to keep balanced its what i did and its been all good so far no vibration etc

[Brianmoooore]

A universal joint, running at an angle is NOT a constant velocity joint - with the input shaft turning at a constant speed, the output shaft continually accelerates and decelerates slightly as it turns. This is largely irrelevant, because when this eccentric motion reaches the second universal joint in the prop, the opposite happens, and the rotational motion is converted back to a constant speed again, provided that the extreme ends of the prop. are parallel with each other, and it has been assembled with the two universal joints lying in the same plane.
Assembling a prop. with the two white dots in line (or 180 degrees out) will achieve this, but that is not the same thing as balancing, and two halves of a prop. from difference sources, will not be properly balanced, except by possible coincidence.
It's possible do do a DIY balance job with two large jubilee clips clamped onto the prop. side by side. When the two worm drives are positioned together, it will have the maximum effect, and when the worm drives are opposite each other, they will have no effect.

[Demlotcrew]

Pretty sure the bearing is on the rear section of an e30 M3 prop and the regular E30's have the bearing on the front section. So not compatible......

[BMG]

Ok, thanks. Small repair needed on the front end then after letting a propshaft 'specialist' work on both bits.

[Demlotcrew]

What is the damage?

[BMG]

In removing the pressed fitting on the front end with the rubber fitting inside, they've made a right mess of it and chewed the hell out of it.

[Demlotcrew]

I see

[jmc330i]

Pretty sure the bearing is on the rear section of an e30 M3 prop and the regular E30's have the bearing on the front section. So not compatible......

Yup. 325i top, E30 M3 bottom...

[Demlotcrew]

Must save that photo as I couldnt remember 100% which way round the configuration was

[BMG]

Sorry, don't have a pic of their 'workmanship' , but couldn't believe the mess they made of it. I thought it would be a simple job for them.

[jmc330i]

Must save that photo as I couldnt remember 100% which way round the configuration was

I only took the photo so I could remember