I have pulled my engine out to try to locate the source of a strange whine which has been occuring when I take my foot off the accelerator. I noticed what appears to be a fine crack underneath the throw out bearing. I have noticed on a spare box I have marks in exactly the same place and I was kind of hoping someone will tell me everything is ok thats normal

EDIT: With the resizing to get the image to upload the area gets hard to see but it is squarish and travels through that area that looks like gear oil is weeping out.

I think u will find its in the thrust beqring

yep

mmm whine in a bearing thats not where i get my wine from

if it occurs when you lift of the throttle it's not the throw out bearing, it should not be spinning until you depress the clutch, it could be in your box

Yeah it is more when I lift off the throttle as I experimented with keeping the revs up while depressing the clutch and it didnt seem to happen then. I guess that means trying out the other box.

The couple of throwout bearings I've had go it's more of a squeal than a whine... similar volume to disk brake squeal, but a bit lower pitch.

Bit late now that the engine is already out, but some tests to possibly try and narrow it down:

1. Sitting stationary... rev in Neutral and let foot off... does it whine ???
2. Sitting stationary... in gear but clutch in... rev it and let your foot off... does it whine ???
3. Car moving, put into neutral... rev it and then let foot off... does it whine ???
4. Car moving, accelerate and then let foot off... keeping it in gear and the clutch out... does it whine ???
5. Car moving, put into neutral and switch off engine... does it whine ???

If it whines for test 1, I'd be thinking maybe the bearing in the gland nut.
If it whines for test 2, throw out bearing.
If it whines for test 3 or 4, box or diff maybe.
If it whines for test 5, I'd be thinking brakes or maybe tyres rubbing or something.

Thanks Sides I will try those out. I thought of a possibility as well, when I put the cluch back in I eye balled it could this be causing the whine/squeal? just to be safe I will loosen the clutch off and realign it on the engine.

Just spin that thrust bearing by hand and you will know if its stuffed. Besides that, put a new one in anyway, and a new clutch and presure plate.

While you have it apart like that, its easy to replace the consumables.

Also back to my origional question (which I forgot to ask) is there a square casting mark that travels under the thrust bearing or are both my boxes cracked. I will try to upload the photo elsewhere to explain what I mean.

looks like a casting flash.

From a engineering point of view I doubt the box would ever crack like that as the loading on them
does not make any logical sense to cause a crack in that pattern.

yes that square pattern is normal in the casting

Thanks thats what I was hoping to hear.

Quote:

Originally posted by Arpspasm I have pulled my engine out to try to locate the source of a strange whine which has been occuring when I take my foot off the accelerator. I noticed what appears to be a fine crack underneath the throw out bearing. I have noticed on a spare box I have marks in exactly the same place and I was kind of hoping someone will tell me everything is ok thats normal EDIT: With the resizing to get the image to upload the area gets hard to see but it is squarish and travels through that area that looks like gear oil is weeping out.