Lotus Elan

Release Bearing Woes

PostPost by: david.g.chapman » Tue Nov 28, 2006 7:33 pm

I have a screeching noise coming from the release (throw-out) bearing on my +2 when starting out on a journey. It happens when the clutch is depressed as you change gear. It sounds as if the bearing is getting dry.

What is strange is that I replaced this bearing no more than 15K miles ago when the clutch was replaced. Last winter (5K miles ago) I had the engine out and looked closely at the clutch - all seemed well with the bearing rotating freely. It felt like new.

I then did something "clever" that might be not so clever! I smeared some LM grease on the bearing and heated it with a blowlamp just enough to melt the grease so it ran inside. When the bearing cooled, it felt fine, although stiffer with the LM grease.

I am wondering if the LM grease is not flowing inside the bearing, so the rollers are running dry while surrounded by grease. What was the bearing filled with when new?

I will try and grind or drill a small hole in the side of the bearing casing through the opening in the bell housing. Hopefully I can fit an extension to my dremel to do this! :lol: Anything but pull the engine for just a bearing! I just need to find out what to pump in. I can then degrease and close the hole with a blob of epoxy.

Dave Chapman.
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PostPost by: types26/36 » Tue Nov 28, 2006 8:07 pm

david.g.chapman wrote:What is strange is that I replaced this bearing no more than 15K miles ago when the clutch was replaced. Last winter (5K miles ago) I


David,
Did you replace the spigot bearing in the end of the crankshaft ? if not my guess it is that and not the release bearing.
Brian
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PostPost by: david.g.chapman » Tue Nov 28, 2006 10:56 pm

I did not replace this, but stuck a clutch centralising tool in to check the operation of the spigot bearing rollers crudely. There was no play I could detect. I then packed this bearing with LM grease as well before assembly.

I get the noise as I apply pressure to the clutch pedal. It is always quiet when the clutch is engaged, and after a minute or so it is quiet all the time while driving. if the car is used every few days or more often than that there is no noise at all.

I sprayed the release bearing with WD40 (carefully)! some months ago, and the noise diappeared for several weeks.

Dave Chapman.
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PostPost by: 1964 S1 » Wed Nov 29, 2006 2:32 am

One or two possibly relevant points... WD40 cleans surfaces after intially lubricating, I would not use it on bearings as it will dilute any grease and create dry running.
I've got a Peugeot 505 with nearly identical behavior, it's been acting that way for years and more than ten thousand city miles. It's never gotten any worse.
Please let us know if you get the hole drilled with the dremel.
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PostPost by: ppnelan » Thu Nov 30, 2006 9:56 am

Drilling into the bearing sounds near-impossible to me. If you did succeed, the bearing grease would pick up all the bits of hard steel you just ground off and they would ruin the bearing as soon as it turned :cry:
So I say DON'T DO IT :!:

I assume you have the correct clutch cover & bearing - the 4-speed has a flat plate on the diaphragm spring fingers for the flat-faced release bearing to press against, while the 5-speed just has a rounded release bearing pressing directly on the spring fingers.

:arrow: Matthew
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PostPost by: david.g.chapman » Thu Nov 30, 2006 12:14 pm

You are quite right, there is a risk of swarf getting into the bearing. :shock:

The trick would be to nearly drill or grind through, a diamond-dust studded ball tip could be the thing to use. You then try to punch through the last bit. You are left with a ragged hole with no swarf inside the bearing. Sounds easy but I will just have to try it to see.

I will do it in a few weeks time over Xmas.

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PostPost by: JJDraper » Sat Dec 02, 2006 7:30 pm

I had a noisey rease bearing - lasted around 20-25k miles in my +2 before disintegrating. No damage when it finally went, just very noisey - clutch still worked! Here is a picture of the aftermath - note the nylon bearing cage. Heat sensitive - re blowtorch?!

Jeremy
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PostPost by: john.p.clegg » Sun Dec 03, 2006 7:35 am

Dave
I honestly don't believe that you are going to try to create a hole in the bearing housing IN SITU to pump in some grease.....You must be madder than me....and that is going some.......I'd only try that in a warm shed with it held in the vice......But Good Luck.

John :wink:
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