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I replaced the rear crank seal on my 1750 a few years (and approximately 4k miles) ago. I did it with the engine in the car and used a third party seal supplied by a respected UK specialist.

Ever since then the car has made a strange squeeling noise like an espresso machine above tickover. Below 1200 rpm it stops suddenly and it rises in pitch with revs. I was told that this can happen when you change the seal and eventually dissapears.

I know that there can be other sources of this type of noise (brake servo lines? and carb seals? etc) but I've checked these and in any case i don't remember there being a noise before I changed the seal. I know that rear seals can be an issue and that replacing them in situ isn't recommended (I didn't know that at the time or I'd have left it alone!), but it seems to be holding so far and I haven't noticed any major leakage. I hope that if it was going to fail it would have happened by now?...

Any ideas?
 

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It's kind of hard to imagine the seal itself making noise, but I guess it's possible. I had the front seal on the trans on a TI torn, the internal spring was rubbing on the shaft, but it didn't make any noise, just leaked like crazy.

I wonder about the "spash ring" behind the seal, if maybe that's somehow caught and turning? It would tear up the seal bore somewhat if true. Alas, may have to dig in, remove engine or trans to find out what's wrong. You can remove the trans and run the engine in place if you jury-rig the starter, it'll balance reasonably on the motor mounts, to watch for what might be happening. Flywheel of course is still in the way though.

Andrew
 

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maybe the bronze bush in the rear crank, where the transmission shaft fits into?

Like Andrew, I can't imagine the seal squeaking, tbh.....if it did it wouldn't squeak for 4 years.....if not inserted correctly, it would more likely wear and then leak.
 

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When the clutch pedal is released, that is, the clutch is engaged, in gear or in neutral, the crankshaft and trans input shaft are locked together, so a noisy pilot bushing wouldn't likely make any sound then. Only when clutch is disengaged, or when releasing and the two shafts spin up or down to match. Though they can squeal, yes. But it's only when the clutch is engaging/disengaging, generally.

Andrew
 

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I replaced the rear crank seal on my 1750 a few years (and approximately 4k miles) ago......but it seems to be holding so far and I haven't noticed any major leakage. I hope that if it was going to fail it would have happened by now?...
I agree with what others have written. In summary:

- Hard to imagine how the seal alone could cause a squealing sound, and if it did, how it would continue sealing after 4K miles.

- Pilot bushing probably not the cause.

What about other parts that were disassembled/re-assembled when the seal was replaced? The throw-out bearing comes to mind; might it be causing the squeal? Does the squealing stop/start when you depress/release the clutch pedal? Anything else inside the bellhousing that might have gotten mis-aligned?
 
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