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Is my diff gone?

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Gustavo7
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Is my diff gone?

Post by Gustavo7 » Wed Sep 26, 2018 3:44 pm

Noticed a clicking noise when driving that increased with speed. Raised the car to see a wetted diff area.

See video for noise when turning one wheel by hand (with the other on the ground).
Seems to have a lot of play too.

What do you guys think? Had to head north this morning so won’t have the opportunity to investigate until the weekend.

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Simon 3.2M
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Is my diff gone?

Post by Simon 3.2M » Wed Sep 26, 2018 4:27 pm

I wouldn't be heading north in that if you were intending to. Sounds like it's dropped all its oil to me. Easy enough to fill on the drive - you may just be looking at a new input shaft seal.
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Is my diff gone?

Post by Gustavo7 » Wed Sep 26, 2018 4:51 pm

Simon 3.2M wrote: Wed Sep 26, 2018 4:27 pm I wouldn't be heading north in that if you were intending to. Sounds like it's dropped all its oil to me. Easy enough to fill on the drive - you may just be looking at a new input shaft seal.
Thanks Simon! Hopefully you are right.

And no, I’m not driving north in the M!! :P
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Is my diff gone?

Post by Yorkie Z » Wed Sep 26, 2018 5:02 pm

Videos are always a bit miss leading but that does sound terrible. I buggered my diff on an Old BMW 330. I broke one of the teeth off the main ring, that sounded like a ticking that increased with speed.
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Is my diff gone?

Post by Z4M-2006 » Wed Sep 26, 2018 5:40 pm

Shat!....

Sounds like the crown wheel is loose!.

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Is my diff gone?

Post by GuidoK » Wed Sep 26, 2018 6:08 pm

Could be your diff but could also be your propshaft.
when the diff turns, the propshaft also turns, and the gearbox has about 1/4 turn play so that could be it. But its more that sound.

And that oil is no good sign.
And do I see a broken CV boot?

Get that thing asap on a ramp and do proper diagnosis. I wouldnt drive a mile with those signs.
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Is my diff gone?

Post by Zoomer » Wed Sep 26, 2018 9:08 pm

I am no expert but ouch that does sound expensive. I hope for your wallets sake I am wrong though.
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Is my diff gone?

Post by bradz » Thu Sep 27, 2018 4:30 pm

That's just the play in the drive train, perfectly normal. My Z4M & M3 are exactly the same and they have both had diff rebuilds.

They are getting to the age where the seals on the Input/output are failing, check it has plenty of oil.

Check prop-shaft doughnut for cracks (Located on end of gearbox) I suspect this is your issue.
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Is my diff gone?

Post by Spaniarduk » Sat Sep 29, 2018 5:13 pm

Gustavo7 wrote: Wed Sep 26, 2018 3:44 pm Noticed a clicking noise when driving that increased with speed. Raised the car to see a wetted diff area.

See video for noise when turning one wheel by hand (with the other on the ground).
Seems to have a lot of play too.

What do you guys think? Had to head north this morning so won’t have the opportunity to investigate until the weekend.

Your video alone and without knowimg exactly the conditions (1 or both wheels up? In gear or neutral?) shows little nothing. I would go as far as to say that what the video shows is absolutely normal. It's what's called 'backslash', which is built-in slack beween the pinion and the crown to allow the teeth to engage at optimum spot while working under load.

With this I am not denying that you have a click and that the click goes up in frequency with speed. Im just saying that ypur video shows something that is perfectly normal.

My suggestion is that you drain the old oil. If there's anything damaged you will soon see metal chips and deposits inbthe oil and the drain plug's magnet (drain plugs normally have a magnet to capture metal bits that otherwise would obliterate the gears in the oil bath)
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Is my diff gone?

Post by Gustavo7 » Sat Oct 06, 2018 12:43 pm

Hey guys, finally had the time to investigate and it’s all good news.

The clicking noise was coming from a wheel spacer (H&R Hubcentric 10mm) which I had fitted recently to replace my 18mm ones.

Turns out the tolerances of one of the spacers was out. The clicking noise was coming from the poor fit between the spacer lip outer diameter and the wheel center inner diameter, even with the wheel bolts torque’d to spec.

Live and learn.

At least it allowed me to spot the sweaty diff before the winter kicked in!
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Is my diff gone?

Post by Z4M-2006 » Sat Oct 06, 2018 1:04 pm

Good news...... :thumbsup:

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Is my diff gone?

Post by Simon 3.2M » Sat Oct 06, 2018 8:04 pm

:thumbsup:
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