Welcome to our resource for MG Car Information.
|
MG MGB Technical - Bad noises from clutch?
I was helping a friend of mine move flat today and when ferrying various bits and pieces to her new place my car started making ominous noises. Sometimes now, but not all the time, when I lift off the clutch I get a weird sort of graunching sound. It is hard to describe the sound but it is like a grinding, rubbing sort of sound. It happens on every gear, only when releasing the clutch and it doesn't always do it. So far it doesn't feel any different, it just makes that awful noise. Could it be the release bearing or clutch giving out? I've only had the car for 9 months or so. It's a 1970 GT and has done 150000+ miles and I have no idea when the release bearing/clutch would have last been looked at. Is there anything simple I can check out myself before taking it to my mechanic? I'd love to pull the engine myself to take a look but unfortunately space and time are against me right now! Simon |
Simon Jansen |
Simon. If you do not know the history of the clutch and throw out bearing, it would be a good time to replace them. At the same time, have the transmission re-sealed, and replace the front and rear seals on the engine. While you are at it, have the clutch hydraulic system rebuilt, including replacement of the flex hose from the hard line to the master cylinder to the slave cylinder. Then, you will be working from a known good system and can monitor the performance. Normally, the clutch and throw out bearing are good for about 80K miles for most people. This may well mean that your clutch system has been replaced once and is beginning to go out for the second time. Without some form of maintenance history, it is difficult to give a definitive answer. Les |
Les Bengtson |
Simon - It is probably one of two things. Either the clutch release bearing or the spigot bush. The release bearing on the B is a simple carbon thrust device and it either works or it doesn't -as yours is only making intermittent noises I don't think it will be this. The second is a small phosphor bronze guide bush which locates the end of the gearbox mainshaft in the end of the crankshaft. This does produce an intermittent grumbling sort of noise (usually when the clutch is fully depressed) as it sometimes turns in its housing in the crank. It's a very simple thing to replace (once the engine is out) and will only cost you two or three dollars. If you are taking the engine out take the opportunity to change the clutch as well. |
John Barton |
Simon, Have a look at the U-joints first, and also look at where the driveshaft flanges bolt up. Sometimes a worn U-J will make noise that sounds like it is in the tranny/clutch. On one of my B's the PO had reused the Nylock nuts too many times, and they started to back off. This caused a similar noise to what you describe. |
Paul K |
Hi, thanks for all the suggestions! I called my mechanic yesterday and he also suggested what Paul says - check my u-joints. I'll have a look this weekend. Went for a drive last night and everything was fine so I guess I just need to keep an eye on things. My mechanic says if he could hear the sound he'd tell right away but of course now it doesn't make it! Thanks for all the help guys. Simon |
Simon Jansen |
This thread was discussed between 28/07/2002 and 29/07/2002
MG MGB Technical index
This thread is from the archive. The Live MG MGB Technical BBS is active now.