MGB GT 1.8 sudden Transmission whine
Discussion
My brother has a 73 gt which has suddenly developed a whine under load - no previous symptoms. Overdrive in or out makes no difference, and coming off the throttle massively reduces it. More speed, more noise, and is louder with speed. We are away in Yorkshire for a week, and no ramps to check diff oil, although will check box oil tomorrow when it is light.
Has anyone experienced sudden diff or box failure (seemed More speed sensitive so diff perhaps main suspect) with little warning, or a similar sudden increase in mechanical noise? Any knowledgeable opinions on the diff or box being susceptible to sudden failure, or how strong either is? It's 250 miles home, so weighing up the options...
I realise it's a rough description, but experiences of similar, and if it left you stranded 50 miles (or however long!) later much appreciated.
Cheers,
ian
Has anyone experienced sudden diff or box failure (seemed More speed sensitive so diff perhaps main suspect) with little warning, or a similar sudden increase in mechanical noise? Any knowledgeable opinions on the diff or box being susceptible to sudden failure, or how strong either is? It's 250 miles home, so weighing up the options...
I realise it's a rough description, but experiences of similar, and if it left you stranded 50 miles (or however long!) later much appreciated.
Cheers,
ian
Ian,
As you say, difficult to tell at a distance, but from what you describe as a whining noise that changes with speed and load it generally points to something up with the box or the diff, although these are normally robust and long lasting units - haven't heard of sudeen failures, other in racing. I am a bit surprised that the location of the noise is not making it fairly apparent whether it is the box or the diff? If the gearbox is working fine and the overdrive going in and out OK, then I would suspect the diff more than the box. Sudden onset rather than gradual onset could point to a thrust washer or the like failing, rather than just wearing gradually.
Any idea whether they are rebuilt units or the originals? There have been some pretty horrendous cheap pattern parts, such as layshafts, made in the past.
Check the oil levels, and even if you can't check the oil level in the diff without a ramp, at least look under and check that the drain plug is still there! Leaks are usually drips though, that are apparent whenever you park, rather than complete sudden oil losses.
One thought if you are there for a week is to trawl the web, MG and/or classic car related etc to find a local specialist up there who you could drive it to and check it over. Don't know the area from that point of view, but google seems to bring up quite a few http://www.google.co.uk/search?hl=en&q=classic...
MG Mark
As you say, difficult to tell at a distance, but from what you describe as a whining noise that changes with speed and load it generally points to something up with the box or the diff, although these are normally robust and long lasting units - haven't heard of sudeen failures, other in racing. I am a bit surprised that the location of the noise is not making it fairly apparent whether it is the box or the diff? If the gearbox is working fine and the overdrive going in and out OK, then I would suspect the diff more than the box. Sudden onset rather than gradual onset could point to a thrust washer or the like failing, rather than just wearing gradually.
Any idea whether they are rebuilt units or the originals? There have been some pretty horrendous cheap pattern parts, such as layshafts, made in the past.
Check the oil levels, and even if you can't check the oil level in the diff without a ramp, at least look under and check that the drain plug is still there! Leaks are usually drips though, that are apparent whenever you park, rather than complete sudden oil losses.
One thought if you are there for a week is to trawl the web, MG and/or classic car related etc to find a local specialist up there who you could drive it to and check it over. Don't know the area from that point of view, but google seems to bring up quite a few http://www.google.co.uk/search?hl=en&q=classic...
MG Mark
Edited by MG Mark on Wednesday 16th September 23:42
Edited by MG Mark on Wednesday 16th September 23:43
Thanks for the help chaps. We isolated it to diff noise this morning, and a local garage put it on their ramps to check diff oil - of which there was very little (could not feel any through the filler plug). It was topped up, taking a fair amount, and the whine now significantly reduced.
Wildoliver - we are near kirbymoorside (Fadmoor).. My brother has posted on here before and mentioned someone around here he chatted with (his login is neilr) which sounds like you! Many thanks for the offer, but we look good to get back tomorrow now.
When on the garage ramps the front diff seal could be seen to have seeped oil, with some spray around the battery boxes - the moral here I guess is more regular checks.
Cheers,
Ian.
Wildoliver - we are near kirbymoorside (Fadmoor).. My brother has posted on here before and mentioned someone around here he chatted with (his login is neilr) which sounds like you! Many thanks for the offer, but we look good to get back tomorrow now.
When on the garage ramps the front diff seal could be seen to have seeped oil, with some spray around the battery boxes - the moral here I guess is more regular checks.
Cheers,
Ian.
I once had a (previously noisy) diff on a Cortina just go bang as I was driving....sounded like a couple of elephants having a scrap under the car ! 
Let it cool, and was able to crawl a few miles home. Replacement axle then fitted.
On another Cortina the pinion seal (front of diff) went and diff flange flapping about; hugely noisy whereas previously quiet. Another replacement axle.
Both had plenty of oil in, but the second one I'd fitted with a 3 litre Capri motor, so possibly the extra torque.
Let it cool, and was able to crawl a few miles home. Replacement axle then fitted.
On another Cortina the pinion seal (front of diff) went and diff flange flapping about; hugely noisy whereas previously quiet. Another replacement axle.
Both had plenty of oil in, but the second one I'd fitted with a 3 litre Capri motor, so possibly the extra torque.
Thanks for the help chaps. We isolated it to diff noise this morning, and a local garage put it on their ramps to check diff oil - of which there was very little (could not feel any through the filler plug). It was topped up, taking a fair amount, and the whine now significantly reduced.
Wildoliver - we are near kirbymoorside (Fadmoor).. My brother has posted on here before and mentioned someone around here he chatted with (his login is neilr) which sounds like you! Many thanks for the offer, but we look good to get back tomorrow now.
When on the garage ramps the front diff seal could be seen to have seeped oil, with some spray around the battery boxes - the moral here I guess is more regular checks.
Cheers,
Ian.
Wildoliver - we are near kirbymoorside (Fadmoor).. My brother has posted on here before and mentioned someone around here he chatted with (his login is neilr) which sounds like you! Many thanks for the offer, but we look good to get back tomorrow now.
When on the garage ramps the front diff seal could be seen to have seeped oil, with some spray around the battery boxes - the moral here I guess is more regular checks.
Cheers,
Ian.
Noisy diff's on MGB's are not uncommon even at relatively low mileages.
If you have a noisy diff the best thing to do is check the level and take the opportunity to top it up with some Molyslip G gearbox and axle treatment. Fantastic stuff!
If you have a noisy diff the best thing to do is check the level and take the opportunity to top it up with some Molyslip G gearbox and axle treatment. Fantastic stuff!
Edited by Kentish on Monday 28th September 22:20
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