I have a strange noise coming from the gearbox. When the clutch is depressed the noise disappears. It sounds like a bearing rattle. I do not think its the
trust race. Has anyone any ideas before I drop the gearbox to investigate?
Gearbox noise
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 rover1021 |
Gearbox noise |
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Posts: 1 Sun, 3-Jan-2010 14:49 |
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OldNoccer |
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Posts: 896 Sun, 3-Jan-2010 15:58 |
I guess dipping the clutch stops the gearbox input shaft, and the internal gearbox pump, and I think the layshaft turns in neutral too.
Presumably it is an LT77 box. Mine sometimes makes odd noises when very cold - usually pulling away after backing out of the drive, as if the SMX oil is a bit too viscous and is whizzing an undriven gear around, maybe the reverse idler gear. It is OK after 100 yards, or maybe its fixed by changing into third. Also gearboxes can make alarming noises if something wedges between them and the bodywork as the normal noises are amplified - I wouldn't have thought that very likely in the Marcos. You could try warming the box, and you could drop the oil and see if there are any clues. However I did have an LT77 in a Rover eat its bearings once, but it had been noisy for some time (except in 4th - which is straight through). Can't think of anything else - is there room on the Mantula to get the box out, or do you have to resort to heaving the engine out complete ? Steve
In seeking to undo one riddle, and find the true, I knit a hundred others new.
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rover1021 |
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Posts: 2 Sun, 3-Jan-2010 17:40 |
Thanks Steve
Yes it is a LT77 gearbox, sorry I forgot to mention that. The strange thing with my noise is that it completely disappears when being driven. It only occurs when the engine is idling with the clutch out. Temperature seems to have no effect. I havent dropped the oil yet to look for clues as I was hoping to drop the box and have a look. Rory tells me its a pain to drop without a ramp hence I may need to use the local garage hence if I have located the problem before hand I can supply the new bearings and not have the car taking up ramp space whilst these are ordered. I tend to think its the taper bearings on the input and layshaft. I was wondering if anyone else has had the same problems. What bearings did your previous Rover eat? Ade |
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OldNoccer |
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Posts: 898 Wed, 6-Jan-2010 00:17 |
If it is OK when being driven then drive it !! I reckon most gearbox problems grow and you get aware of them over time (unless you are playing deafening
stereo). So the news is good if it drives OK - really good !! In my experience a shagged LT77 will be really noisy in 3rd and much quieter in 4th.
I reckon it is a fair chance it is the clutch thrust bearing rattling, which is not a good sign, but far cheaper than a gearbox overhaul. Steve
There's a lot of talk these days about green transport. Well, I am ahead of the game, I already have green transport ... British racing green.
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rover1021 |
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Posts: 3 Wed, 6-Jan-2010 21:30 |
Hi Steve Thrust bearing was my original thought but when the clutch is disengaged it will not be turning but this is a constant bearing rattle hence I am
thinking its the taper bearings. Ade
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