Prop shaft nock

[lee1981]

Afternoon all,

Just a quick question. I've the common clunck coming from what sounds like the gearbox/propshaft which is heard mainly when driving, not just changing gear at a standstill.

I've read somewhere in the past that it's quite a common noise with the grease on the propshaft? Specialised grease or something?

Wondering how much of a difficult job it is getting the propshaft off to do the work? I've had the exhaust off from the manifold back of late so shouldn't be too much hassle removing it which I'm guessing I will need too to gain access.

Any info would me much appreciated.

Cheers,

Lee.

 

[buzyg]

Doesn't sound common or right to me. Hopefully I have that wrong.

 

[mjennings23]

Once the exhaust is off it's pretty much just the heatshield to remove I believe.

 

[skelters]

Heard of this happening in the past on some cars. Quite possibly the Flex Disc.....

Driveshaft clunking when pulling away. Flex disc and cs bearing shot?
https://z4-forum.com/forum/viewtopic.php?t=97640

BMW Giubo Flex Disc + Driveshaft + Transmission Mounts Install DIY
[youtube]8E5Mg9MX7C8[/youtube]

 

[JamieZ4C]

I have this "clunk" and I'm fairly sure it is quite common.

If it's the guibo or 'donut' you would normally get a clunk when selecting first gear from neutral (and perhaps reverse too). Mine doesn't do this and I know the previous owner replaced the guibo.

I can get mine to make the clunk if I blip the accelerator whilst pootling along in first or second not much above idle. It's a metallic clink/clunk coming from directly beneath/behind me and I believe it is where the prop enters the diff and indeed it just needs regreasing. The grease is 83230417754.

Hoping to get mine done this year. A member on here (Markos_Z4) had the same issue fixed and advised me it probably wasn't worth trying to DIY and to just pay a garage to do it. Of course, very good advice which I'll probably ignore :lol:

The good news is I don't think much harm is being done, it just doesn't sound great. Hope that helps and good luck diagnosing and fixing your clunk

 

[Ewazix]

An old thread worth reading

https://z4-forum.com/forum/viewtopic.php?f=3&t=97640&start=15

 

[Chris_D]

An old thread worth reading

https://z4-forum.com/forum/viewtopic.php?f=3&t=97640&start=15

Ive yet to conclude that thread with fix followup.
I'll be tackling it when the warmer weather hits.
Hasnt given me any issue or concern since and as others say it sounds worse than it is.
:roll:

 

[paddy wright]

As said above it’s the prop shaft doughnut by the sounds of it.

 

[MACK]

I had the propshaft clunk when I first got mine. I used the loctite grease/liquid metal on the splines and never had an issue since. However this sounds more like the doughnut is the issue, as the spines only really present when selecting first/reverse from stationary, not on the move.

 

[lee1981]

That's brilliant,

Thanks for the replies guys. I'll look at doing the splines and the doughnut and order them next week.

Might as well so them both while I'm at it.

I'll update upon completion or if I find anything else that's causing the noise. Hopefully it's nothing to do with the gear box itself.

Cheers again,

Lee