I think I might need a new gearbox - nasty noise
Discussion
After 6 hours of relatively fast motorway miles driving from Calais to the Ring my gearbox started to make a horrible noise (very bad timing, I was not happy).
I've read a hundred and one forum topics about various clutch and gearbox noises but none of them seem quite the same as mine so I wanted some opinion. Symptoms are:
On idle with the clutch engaged there is a light whirring noise from the clutch/gearbox area. Like a metallic version of an untuned radio.
When I press the clutch in the noise quickly drops off (most people at this point say clutch release bearing).
With the clutch engaged again and still in idle the noise increases with engine revs when I press the accelerator.
When I'm driving along the whirring/whomping/grinding noise increases in speed and noise as I accelerate through 1st, 2nd and 3rd. (Noise is in-line with the engine, not road speed)
4th gear does not seem to make the noise (the 1:1 ratio gear). I can't tell whether 5th makes the noise or not. Possibly due to engine/road noise.
Does anyone have any ideas and know of any good (and reasonably priced) garages in North-West London?
Cheers,
Mike
I've read a hundred and one forum topics about various clutch and gearbox noises but none of them seem quite the same as mine so I wanted some opinion. Symptoms are:
On idle with the clutch engaged there is a light whirring noise from the clutch/gearbox area. Like a metallic version of an untuned radio.
When I press the clutch in the noise quickly drops off (most people at this point say clutch release bearing).
With the clutch engaged again and still in idle the noise increases with engine revs when I press the accelerator.
When I'm driving along the whirring/whomping/grinding noise increases in speed and noise as I accelerate through 1st, 2nd and 3rd. (Noise is in-line with the engine, not road speed)
4th gear does not seem to make the noise (the 1:1 ratio gear). I can't tell whether 5th makes the noise or not. Possibly due to engine/road noise.
Does anyone have any ideas and know of any good (and reasonably priced) garages in North-West London?
Cheers,
Mike
There is a release bearing and a spigot bearing. I'm not sure but I think the release bearing is sometimes called the thrust bearing.
It could be that or it could be a gearbox bearing or even something nasty like gear or synchromesh damage. Does the gear change feel fine or has it changed since it started making noises?
It could be that or it could be a gearbox bearing or even something nasty like gear or synchromesh damage. Does the gear change feel fine or has it changed since it started making noises?
MX-5 Lazza said:
There is a release bearing and a spigot bearing. I'm not sure but I think the release bearing is sometimes called the thrust bearing.
It could be that or it could be a gearbox bearing or even something nasty like gear or synchromesh damage. Does the gear change feel fine or has it changed since it started making noises?
If it were the spigot bearing wouldn't it just make a noise all the time no matter what you did with the pedal?It could be that or it could be a gearbox bearing or even something nasty like gear or synchromesh damage. Does the gear change feel fine or has it changed since it started making noises?
I could be wrong, its happened before.....once.....1984 I think it was
Mark
The gear change is absolutely fine as is the engaging and disengaging of the clutch.
Some have suggested it could be the layshaft in the gearbox is buggered. Unfortunately I'm not in a position to easily lift the car up and drop out the gearbox to have a look before purchasing parts (Live on a relatively busy road with only street parking.)
Some have suggested it could be the layshaft in the gearbox is buggered. Unfortunately I'm not in a position to easily lift the car up and drop out the gearbox to have a look before purchasing parts (Live on a relatively busy road with only street parking.)
I wasn't suggesting it could be the spigot bearing, just pointing out what bearings were there and which is considered the "thrust" bearing 
Sounds like the gearbox is probably fine then though the input shaft bearing is still a possible. The most likely thing is the release bearing though.
Good news is that it shouldn't spoil your Ring fun (ooh err). It might be noisy but it shouldn't cause any damage.
Sounds like the gearbox is probably fine then though the input shaft bearing is still a possible. The most likely thing is the release bearing though.
Good news is that it shouldn't spoil your Ring fun (ooh err). It might be noisy but it shouldn't cause any damage.
How can it be the release bearing (thrust bearing), if the noise disappears when he presses the clutch?. With the clutch pedal up, the gearbox input shaft is still spinning, even in neutral.
When you press the clutch, this shaft will stop turning. Therefore this does point to something unside the gearbox. A further clue is the fact the noise disappears in 4th. Depending on the gearbox layout, the 1:1 ratio takes no path through the layshaft, therefore on such boxes, quiet operation in 4th only could be a sign of worn layshaft bearings.
You'd be best to get an opinion off a good gearbox specialist, and then take it from there.
When you press the clutch, this shaft will stop turning. Therefore this does point to something unside the gearbox. A further clue is the fact the noise disappears in 4th. Depending on the gearbox layout, the 1:1 ratio takes no path through the layshaft, therefore on such boxes, quiet operation in 4th only could be a sign of worn layshaft bearings.
You'd be best to get an opinion off a good gearbox specialist, and then take it from there.
Unfortunately it did spoil my ring fun. As we weren't 100% sure what it was I did 1 casual lap (as I'd replaced all the springs and dampers and driven 6 hours just for the Ring) then sat in the car park for the rest of the day not wanted to break down on the continent 
.
Bearings it is then. Guess I can start there and see what happens.
Cheers for the replies.
.Bearings it is then. Guess I can start there and see what happens.
Cheers for the replies.
Id willing to bet 100% that its the input shaft on the G.Box. My 5 had exactly the same symptoms. I changed the clutch release bearing and it was still there. Changed the box and it was gone.
If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
seismic22 said:
Id willing to bet 100% that its the input shaft on the G.Box. My 5 had exactly the same symptoms. I changed the clutch release bearing and it was still there. Changed the box and it was gone.
If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
Yep, that is what others have suggested and I'm glad I've found someone that has had exactly the same problems (even if it does point to needing a new gearbox.)If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
Out of interest how long did it take and how much did it cost? Did you do it yourself or get a garage to do it?
seismic22 said:
Id willing to bet 100% that its the input shaft on the G.Box. My 5 had exactly the same symptoms. I changed the clutch release bearing and it was still there. Changed the box and it was gone.
If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
Yep, that is what others have suggested and I'm glad I've found someone that has had exactly the same problems (even if it does point to needing a new gearbox.)If you think about it and if when the clutch is depressed the noise dissappears, its the only common and logical thing it can be.
I drove mine making the noise for quite a while it got worse and worse to the point that i ended up being scared that it was going to explode. All that time it selected gears perfectly.
Out of interest how long did it take and how much did it cost? Did you do it yourself or get a garage to do it?
I am not a mechanic but I have self taught basic skills with cars (im 23).
The car was a daily driver so i was concerned i wouldnt get it done in a weekend and initally when i changed the clutch thinking it was the release bearing I paid somebody to help me do it on axel stands. Took a day and a half on the road side but we had issues with the exhaust down pipe bracket getting in the way, eventually cut it off.
Second time i needed to do it after I realised it was the box that had the issue I did it myself on axel stands on my drive. Got the 5 in the air as high as I could. With a second set of hands to help me guide the new box into position (v.tricky on your own on stands and with the PPF still in place) I did it in one day with limited tools. Your need some extension bars to reach the Gearbox/bell housing bolts!
Cost: S/H known G.box - £40
Exedy Clutch kit - £110 (i think)
Add in some gearbox oil on top of that!
The car was a daily driver so i was concerned i wouldnt get it done in a weekend and initally when i changed the clutch thinking it was the release bearing I paid somebody to help me do it on axel stands. Took a day and a half on the road side but we had issues with the exhaust down pipe bracket getting in the way, eventually cut it off.
Second time i needed to do it after I realised it was the box that had the issue I did it myself on axel stands on my drive. Got the 5 in the air as high as I could. With a second set of hands to help me guide the new box into position (v.tricky on your own on stands and with the PPF still in place) I did it in one day with limited tools. Your need some extension bars to reach the Gearbox/bell housing bolts!
Cost: S/H known G.box - £40
Exedy Clutch kit - £110 (i think)
Add in some gearbox oil on top of that!
seismic22 said:
I am not a mechanic but I have self taught basic skills with cars (im 23).
The car was a daily driver so i was concerned i wouldnt get it done in a weekend and initally when i changed the clutch thinking it was the release bearing I paid somebody to help me do it on axel stands. Took a day and a half on the road side but we had issues with the exhaust down pipe bracket getting in the way, eventually cut it off.
Second time i needed to do it after I realised it was the box that had the issue I did it myself on axel stands on my drive. Got the 5 in the air as high as I could. With a second set of hands to help me guide the new box into position (v.tricky on your own on stands and with the PPF still in place) I did it in one day with limited tools. Your need some extension bars to reach the Gearbox/bell housing bolts!
Cost: S/H known G.box - £40
Exedy Clutch kit - £110 (i think)
Add in some gearbox oil on top of that!
Out of interest how high did you get your 5 to work on it?The car was a daily driver so i was concerned i wouldnt get it done in a weekend and initally when i changed the clutch thinking it was the release bearing I paid somebody to help me do it on axel stands. Took a day and a half on the road side but we had issues with the exhaust down pipe bracket getting in the way, eventually cut it off.
Second time i needed to do it after I realised it was the box that had the issue I did it myself on axel stands on my drive. Got the 5 in the air as high as I could. With a second set of hands to help me guide the new box into position (v.tricky on your own on stands and with the PPF still in place) I did it in one day with limited tools. Your need some extension bars to reach the Gearbox/bell housing bolts!
Cost: S/H known G.box - £40
Exedy Clutch kit - £110 (i think)
Add in some gearbox oil on top of that!
I've read an article about changing the gearbox that states you need to get it about 20-28 inches off the floor. That is waaaaay higher then any axle stands. The only ones I have are pretty standard sized so I'm concerned about not being able to get the 5 high enough. It needs to be fairly high just to slide the gearbox underneath the car.
mikey_p said:
That is waaaaay higher then any axle stands. The only ones I have are pretty standard
18-20 inches or so sounds about right for a small gearbox like the MX. Once the gearbox is dropped down, you can usually tip them over on their side to get out out from under the car. It is a bit much for ordinary little axle stands, but you can get taller ones for not much cash.I've got a pair of these and they are excellent, max height is around 20 inches. I think they were 20'odd quid.
http://www.halfords.com/webapp/wcs/stores/servlet/...
If you've not already got one, its worth investing in a decent low-entry high lift trolley jack, for working on a car like the MX5. Something like this
http://www.ebay.co.uk/itm/ARCAN-3-TON-PROFESSIONAL...
I don't know about a Mk1, but on the Mk2 some of the bellhousing bolts were quite hard to get to, especially the ones on the right hand side, as the inlet plenum gets in the way.
Gearbox is do-able with pretty standard stands, I did my clutch in the garage. You will need a mate though.
some bellhousing bolts are awkward but all reachable with a variety of extensions. hardest bit is lining everything up when re-assembling without trapping anything.
Remove the centre console and s
t boots and use rope round the gearbox through the shifter hole, to support the weight of the box.
You can push the front of the engine up a touch too to angle the gearbox down, making it easier to get to.
some bellhousing bolts are awkward but all reachable with a variety of extensions. hardest bit is lining everything up when re-assembling without trapping anything.
Remove the centre console and s
t boots and use rope round the gearbox through the shifter hole, to support the weight of the box.You can push the front of the engine up a touch too to angle the gearbox down, making it easier to get to.
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