Is my diff gone?

Gustavo7

Member
 London
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.

[youtube]kiyc2d0akjo[/youtube]
 
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.
 
Simon 3.2M said:
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
 
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.
 
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.
 
I am no expert but ouch that does sound expensive. I hope for your wallets sake I am wrong though.
 
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.
 
Gustavo7 said:
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.

[youtube]kiyc2d0akjo[/youtube]

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)
 
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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