E85 - Differential Input Flange ‘Clunk’

[Anonymous]

Hello,

I’ve been doing some reading on the forum recently around an issue I’ve had with my E85 3.0Si since my ownership of 2 years.

Occasionally (3/10 times), when I engage first gear or reverse gear, feather the throttle and or drop/engage the clutch quickly, I get a metallic clunk/tap sound.

I’ve done some research and I think this is the common niggle involving insufficient grease on the differential input flange (there are a few posts on the forum regarding this issue).

I have explained the repair to my local garage and I have been quoted £120 to repair (scope could change depending on seized bolts in the exhaust - which they will be)

I was after some advice, the car is in good order but is now 13 years old. The issue seems minor and I was wondering if it was worth getting this done or not? I’m opposed to shelling out money for the sake of a nice to have.

Any advice would be great.

Cheers,

Strav

 

[AveZ4coop]

I have this issue too (2006 Z4C). General consensus on the forum seems to be it is OK to leave. It really annoys me though, so may look at having it done. £120 seems very reasonable.

 

[Anonymous]

I have this issue too (2006 Z4C). General consensus on the forum seems to be it is OK to leave. It really annoys me though, so may look at having it done. £120 seems very reasonable.

Yeah I know what you mean, it’s fairly annoying when it happens but I soon forget about it. I think the main noise is coming from the heavier flange baseplate contacting the differential rather than the splines inside.

I think £120 is reasonable too, but I’ve had two new control arms and a rear coil spring recently so I need to let the wallet recover.

But, I would have it done if it was adversely affecting the car.

Has anyone on the forum with this issue experienced a failure or the sound progressing?

Cheers,

Strav

 

[AveZ4coop]

No one has mentioned any failures. Most people just live with it. Mine has been doing it for about two years now and it has got no worse.

 

[mr nurburgring]

I just live with it, mine has been doing it 8 years so I’ll not worry.

 

[Anonymous]

That’s good to know, I’ll probably leave it for now unless it get far more frequent and louder.

Thanks for your input.

Strav.

 

[dougie1142]

Trust me, £120 is a bargain! Unless you've had you're exhaust off before, it'll be an absolute ballache and likely cost you that just to remove the exhaust. Bear in mind that replacement stretch bolts are required for the input flange and these aren't super cheap (they are BMW specific ones), so i'd be sceptical the price would be £120 once all is said and done. Annoyingly once you remove the exhaust, the actual job of greasing the input flange is really easy! I had the exact same thing and it took me about 3 days of lying on my back under the car drilling out the Inconel exhaust studs! Once that was done it was alright though.

 

[Anonymous]

I’m pretty sceptical about the £120 quote too. It was based on me describing the work required from a in depth post from on here.

I asked the garage to have a look into it when the car was in for repairs on the control arms and rear spring but they couldn’t replicate the sound, so offered no comment but said they could do it with more info. To be fair to them they did say that the scope could change due to bolts needing heating or removing.

In an ideal world id like it done, but might have to put it off.

Out of interest did the grease sort your clunk?

Cheers,

Strav

 

[Anonymous]

Trust me, £120 is a bargain! Unless you've had you're exhaust off before, it'll be an absolute ballache and likely cost you that just to remove the exhaust. Bear in mind that replacement stretch bolts are required for the input flange and these aren't super cheap (they are BMW specific ones), so i'd be sceptical the price would be £120 once all is said and done. Annoyingly once you remove the exhaust, the actual job of greasing the input flange is really easy! I had the exact same thing and it took me about 3 days of lying on my back under the car drilling out the Inconel exhaust studs! Once that was done it was alright though.

Also since you have done the job yourself (although I like to get stuck in, I don’t have space to safely jack up the car and get stuck in). Out of interest, was the original grease absolutely knackered, partly worn, or pretty good just not enough of it?

And did you notice any of excessive wear on the input splines from lack of grease (I.e metal shards and debris)

Do you also recon the sound was coming from the actual baseplate engaging/disengaging or was it from the splines?

Cheers,

Strav

 

[dougie1142]

Trust me, £120 is a bargain! Unless you've had you're exhaust off before, it'll be an absolute ballache and likely cost you that just to remove the exhaust. Bear in mind that replacement stretch bolts are required for the input flange and these aren't super cheap (they are BMW specific ones), so i'd be sceptical the price would be £120 once all is said and done. Annoyingly once you remove the exhaust, the actual job of greasing the input flange is really easy! I had the exact same thing and it took me about 3 days of lying on my back under the car drilling out the Inconel exhaust studs! Once that was done it was alright though.

Also since you have done the job yourself (although I like to get stuck in, I don’t have space to safely jack up the car and get stuck in). Out of interest, was the original grease absolutely knackered, partly worn, or pretty good just not enough of it?

And did you notice any of excessive wear on the input splines from lack of grease (I.e metal shards and debris)

Do you also recon the sound was coming from the actual baseplate engaging/disengaging or was it from the splines?

Cheers,

Strav

Yeah, not sure it would be a job for axle stands, unless you like being squeezed under a car for hours on end (or unless you've got some wizardry to get the exhaust off quickly). I used a manual lift for mine, so i could get it quite high up.

The grease was just sparse and dried up, there was little left on the contact patch that makes the "clunk".

No excessive wear, everything looked good and nothing for concern at all.

Hard to pinpoint exactly where the noise was coming from, i just greased everything but they recommend you grease the rear of the flange. It definitely resolved the issue, but no doubt will require attention again in the future. Having said that it's an easy job if your exhaust comes off easily, could be done in a couple of hours max. I've replaced my original exhaust studs with just good old fashioned, nuts, bolts and washers so should make removing the exhaust a doddle in the future.

It's not the best, but you can see a couple photos halfway down the page here:

https://z4-forum.com/forum/viewtopic.php?f=2&t=122457

 

[Anonymous]

Trust me, £120 is a bargain! Unless you've had you're exhaust off before, it'll be an absolute ballache and likely cost you that just to remove the exhaust. Bear in mind that replacement stretch bolts are required for the input flange and these aren't super cheap (they are BMW specific ones), so i'd be sceptical the price would be £120 once all is said and done. Annoyingly once you remove the exhaust, the actual job of greasing the input flange is really easy! I had the exact same thing and it took me about 3 days of lying on my back under the car drilling out the Inconel exhaust studs! Once that was done it was alright though.

Also since you have done the job yourself (although I like to get stuck in, I don’t have space to safely jack up the car and get stuck in). Out of interest, was the original grease absolutely knackered, partly worn, or pretty good just not enough of it?

And did you notice any of excessive wear on the input splines from lack of grease (I.e metal shards and debris)

Do you also recon the sound was coming from the actual baseplate engaging/disengaging or was it from the splines?

Cheers,

Strav

Yeah, not sure it would be a job for axle stands, unless you like being squeezed under a car for hours on end (or unless you've got some wizardry to get the exhaust off quickly). I used a manual lift for mine, so i could get it quite high up.

The grease was just sparse and dried up, there was little left on the contact patch that makes the "clunk".

No excessive wear, everything looked good and nothing for concern at all.

Hard to pinpoint exactly where the noise was coming from, i just greased everything but they recommend you grease the rear of the flange. It definitely resolved the issue, but no doubt will require attention again in the future. Having said that it's an easy job if your exhaust comes off easily, could be done in a couple of hours max. I've replaced my original exhaust studs with just good old fashioned, nuts, bolts and washers so should make removing the exhaust a doddle in the future.

It's not the best, but you can see a couple photos halfway down the page here:

https://z4-forum.com/forum/viewtopic.php?f=2&t=122457

Thanks for the info, I’ve decided that I will leave it for now, may address again in the future if it’s still doing my head in.

Cheers,

Strav

 

[Gee]

Yeah, not sure it would be a job for axle stands, unless you like being squeezed under a car for hours on end (or unless you've got some wizardry to get the exhaust off quickly). I used a manual lift for mine, so i could get it quite high up.

The grease was just sparse and dried up, there was little left on the contact patch that makes the "clunk".

No excessive wear, everything looked good and nothing for concern at all.

Hard to pinpoint exactly where the noise was coming from, i just greased everything but they recommend you grease the rear of the flange. It definitely resolved the issue, but no doubt will require attention again in the future. Having said that it's an easy job if your exhaust comes off easily, could be done in a couple of hours max. I've replaced my original exhaust studs with just good old fashioned, nuts, bolts and washers so should make removing the exhaust a doddle in the future.

It's not the best, but you can see a couple photos halfway down the page here:

https://z4-forum.com/forum/viewtopic.php?f=2&t=122457

Slightly off topic but I'm liking that scissor lift!