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MG Midget and Sprite Technical - Standard gearbox adviice
Hi all, I have a 1275 RWA midget in standard trim. I have a condition with the gearbox which is very common. There is a loud whine on the overun which I find disturbing. I have looked at the 5 speed option , I do not want to go this route as I like originality.and its is very expensive. My question is, if I replace the standard gearbox will I find a big improvment or are they all the same? I have also been advised to use a large measure of Molyslip to quieten the promle,m. As the syncromesh is perfect I am reluctant to try this as I have heard it stops the syncro working. I would value some aadvice please Thanks Bryan |
B Gore |
Probably layshaft bearings. Does it make this noise in direct drive(top) or only in the lower gears? |
Art Pearse |
My Midget 'box did exactly the same. It worked perfectly but made a loud noise. Shortly after I sold the car I gather it started jumping out of gear. These gearboxes are never completely quiet, but if the noise is obtrusive, something is amiss, probably the layshaft bearings. |
Mike Howlett |
always a good idea to check the oil level and quality of the oil in there or a thorough drain and refill with fresh good quality oil have the oil as hot as possible at drain and leave to drain for as long as reasonably required to get out as much of the old oil and muck as reasonably possible you can also check the quality of the old oil and see if too many and different bits are in it which may help you decide your next course of action |
Nigel Atkins |
ETA: I meant to also put checking the oil is a no cost thing to do and changing the oil is very inexpensive and advisable if you don't know when it was last done checking g/box oil level is a 6 months/6k-mile service check but is often never done at all same as changing the oil is often never done unless the g/box is worked on I doubt changing the oil will give you much improvement but it might give you some (as would topping it up if it was very low but if it's vet low that suggests lack of servicing checks - or a sudden big leak) same with r/axle I'd changing the oil if I didn't know when it was last done and then there's the matter of what's loud to one is near normal to another |
Nigel Atkins |
Do you have a leak from the rear of the gearbox at all? If you do then the noise could be related to the rear oil seal. Mine was noisy until the seal failed! Relatively easy to fix and cheap compared to a new box and the related labour costs. |
Dave Squire (1500) |
Thanks for replies but ewhere are they? I have logged in etc Bryan |
B:J: Gore |
Thanks for replies guys, i will put new oil but i,m sure its ok. So far nobody commented on usung Molyslip, has no one tried it? Bryan |
B:J: Gore |
I rebuilt in my road Sprite a couple of years ago with all new bearings and it still makes a a bit of noise particularly on the overrun when really hot. I have only used Molyslip in my racing Sprite which despite some really hard use over several seasons never let me down. Can't tell if it was any quieter though as it was straight cut. I changed the oil every other race. |
Bob Beaumont |
I've used Molyslip before and not really noticed a difference, it seems to remain suspended in the g/box oil a mate tried it in his B and said it quieten things down that's why I tried I'd suggest a thorough oil change first and if that doesn't work you could suck some of the fresh oil out and add Molyslip doing it in stages will let you know what's most effective and save you moving to the next stage if it's not required |
Nigel Atkins |
This thread was discussed between 31/03/2013 and 01/04/2013
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