Is my gearbox about to explode???
Discussion
I have a 92 mk1 (165k kms on it) which I've run for about 10,000kms of 10-mile commutes, with no issues - to start with the gearbox was very rattly when engine braking but it quietened down over time. I put in new gearbox oil, a new clutch and new spigot bearing when I bought it.
Last weekend it did a 150-mile trip to Scotland and by the time it got there the box was sounding very rattly when gently accelerating or engine-braking. During the week it seemed to get louder, with a sort of brief metallic grating when changing gear.
On Friday after 70 miles of being really careful and listening to some terrible noises at low revs I finally thought 'screw-it' and absolutely caned it home for the remaining 70 miles through Kielder and gradually it seemed to quiten down again, by the time I got home it was back to the typical fairly loud stones-in-a-tin noises when engne braking or accelerating between about 1500 and 300rpms. Over 3000rpms it seems to shut up.
It's got to do another round trip to Scotland this week, so any ideas whether it's about to die on me or are these just the typical noises the transmission makes? Did my short-range commuting just gum it up or something and now I've unclogged it?
Last weekend it did a 150-mile trip to Scotland and by the time it got there the box was sounding very rattly when gently accelerating or engine-braking. During the week it seemed to get louder, with a sort of brief metallic grating when changing gear.
On Friday after 70 miles of being really careful and listening to some terrible noises at low revs I finally thought 'screw-it' and absolutely caned it home for the remaining 70 miles through Kielder and gradually it seemed to quiten down again, by the time I got home it was back to the typical fairly loud stones-in-a-tin noises when engne braking or accelerating between about 1500 and 300rpms. Over 3000rpms it seems to shut up.
It's got to do another round trip to Scotland this week, so any ideas whether it's about to die on me or are these just the typical noises the transmission makes? Did my short-range commuting just gum it up or something and now I've unclogged it?
Sounds a bit like my '91 1.6 with a similar mileage. The noise on mine is at its worst around 3000 to 4000 rpm on the overrun but it can also make some noise under power. Trouble is, I can't be sure where it's coming from: diff, gearbox or clutch. (It had a replacement clutch with a lightened flywheel about 6 months ago, before I bought it.) I sometimes wonder if it's even just exhaust resonance. I've changed all the oils but to no effect and I'm reluctant to start what would be a major job to replace gearbox or diff until I'm sure what the problem is. I've therefore resolved just to keep using it until it get's worse and the source becomes clear. From experience of other cars though, provided they're well lubricated, things like noisy axles can keep going for ever!
There should be no noise as std.
Notchy when cold is pretty common and can be helped by various oils.
Noise is pretty rare from the box but fairly common from the diff (with a 1.6)
Personally I'd want it checked out and fixed as its either going to cost you now (and you can get use from it) or when you sell it as buyers will want a big discount.
Boxes are cheap at sub £100 and I usually put Mk2 boxes in as they don't tend to heave the 'notchy when cold' issues.
Notchy when cold is pretty common and can be helped by various oils.
Noise is pretty rare from the box but fairly common from the diff (with a 1.6)
Personally I'd want it checked out and fixed as its either going to cost you now (and you can get use from it) or when you sell it as buyers will want a big discount.
Boxes are cheap at sub £100 and I usually put Mk2 boxes in as they don't tend to heave the 'notchy when cold' issues.
I'm pretty sure the gearbox oil is full as I changed it last year and it doesn't leak. No idea about the diff, but the noise is definately coming from the front of the car, in the passenger footwell / tunnel area when sitting in the drivers seat.
I'm not bothered about resale value etc.. as the car is very tatty and I'm going to completely rebuild it as a project next year, I just need it to make one more round trip to Scotland of about 500 miles in total.
Rading the various forums there seems to be a very common issue with rattling within the gearbox following clutch changes, possibly rattling selector forks, making a noise that sounds like stones being poured down a metal pipe, which is how mine sounds. Some people say their car is very loud, but I don't know how relative "loud" is - my rattle sounds very loud at low revs when there's no engine noise, but above about 3000rpm you can't hear it unless on the overrun.
I'm not bothered about resale value etc.. as the car is very tatty and I'm going to completely rebuild it as a project next year, I just need it to make one more round trip to Scotland of about 500 miles in total.
Rading the various forums there seems to be a very common issue with rattling within the gearbox following clutch changes, possibly rattling selector forks, making a noise that sounds like stones being poured down a metal pipe, which is how mine sounds. Some people say their car is very loud, but I don't know how relative "loud" is - my rattle sounds very loud at low revs when there's no engine noise, but above about 3000rpm you can't hear it unless on the overrun.
Edited by anonymous-user on Sunday 26th July 11:57
I've just checked the various oil levels - the gearbox oil is just about full up (as best as I can judge on a sloping drive) and is clear and yellow, and the diff oil is full and is a funny bright purple colour.
I've loosened the PPF bolts, jacked up the rear of the gearbox a little and retighten the PPF to see if that helps, as recommended on the owners club forums...a test drive will see if it made any difference.
I've loosened the PPF bolts, jacked up the rear of the gearbox a little and retighten the PPF to see if that helps, as recommended on the owners club forums...a test drive will see if it made any difference.
Just been for a 30km test drive and it sounds pretty quiet - with the windows and roof up I can hear a quiet rattle when engine braking on the overrun, and there is a slight rattle when accelerating gently either at low revs or in too high a gear, and a just-audible whine in 2nd and 3rd when accelerating gently between about 1500 and 2500 rpm. Above 3000 or with the drivers window open 3 inches I can't hear any sounds at all.
The car has a stripped interior with just a thin piece of carpet and no sound proofing, so chances are it would sound noisier anyway.
I'll take a chance and see if it gets me to Scotland tomorrow.
The car has a stripped interior with just a thin piece of carpet and no sound proofing, so chances are it would sound noisier anyway.
I'll take a chance and see if it gets me to Scotland tomorrow.
Edited by anonymous-user on Sunday 26th July 15:03
Basically its if the PPF wasn't put back into the correct position (and most people let it drop) then you should realign it.
As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
Yeah, that's what i did - shove a jack under the tail of the gearbox, loosen the bolts at that end of the ppf, then jacked the box up about an inch, pushed the ppf towards the centre and tightened the bolts back up. I didn't loosen the bolts at the rear of the PPF.
Anyway, it made it to Scotland and it still sounds exactly the same, with just that same rattling under deceleration and rattling and whine under gentle acceleration at low revs. It's being retired at the end of this week to become a winter rebuild project (before the sills drop off) so it's got about 400 miles left to do, fingers crossed it makes it!!!
Anyway, it made it to Scotland and it still sounds exactly the same, with just that same rattling under deceleration and rattling and whine under gentle acceleration at low revs. It's being retired at the end of this week to become a winter rebuild project (before the sills drop off) so it's got about 400 miles left to do, fingers crossed it makes it!!!
Edited by anonymous-user on Monday 27th July 13:36
OnlyMX5ives said:
Basically its if the PPF wasn't put back into the correct position (and most people let it drop) then you should realign it.
As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
I've found a massive thread on this on one of the US forums. There's clearly more than one kind of noise being discussed but a fairly common theme that emerges is that the noise that I think I have appears after a clutch replacement has been done and especially if a non standard clutch was fitted. However, the issue seems to be not so much the clutch itself as the fact that the PPF has been disturbed. The thinking is that if it's not replaced in exact alignement then it preloads the drivetrain, causing the noise that I have between 3,000 to 4,000 (typically) on the overrun. A light weight clutch (as mine was fitted with before I bought it) tends to exaggerate the effect. People on the forum describe living with the noise for years, despite replacing virtually every imaginable component in the transmission and exhaust.As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
This seems to fit my symptoms but my question is how can the PPF be fitted out of alignment? I've not done any work on it yet but given its multiple attachment bolts at both gearbox and diff casings, is it not by definition, aligned? I intend to have a closer look in a week or so when I get back from hols but any comments will be welcome!
gdaybruce said:
OnlyMX5ives said:
Basically its if the PPF wasn't put back into the correct position (and most people let it drop) then you should realign it.
As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
I've found a massive thread on this on one of the US forums. There's clearly more than one kind of noise being discussed but a fairly common theme that emerges is that the noise that I think I have appears after a clutch replacement has been done and especially if a non standard clutch was fitted. However, the issue seems to be not so much the clutch itself as the fact that the PPF has been disturbed. The thinking is that if it's not replaced in exact alignement then it preloads the drivetrain, causing the noise that I have between 3,000 to 4,000 (typically) on the overrun. A light weight clutch (as mine was fitted with before I bought it) tends to exaggerate the effect. People on the forum describe living with the noise for years, despite replacing virtually every imaginable component in the transmission and exhaust.As the spec is pretty high (and requires a ramp) most simply loosen the box and diff PPF mounting bolts jack the PPF up and retighten.
Crude but seemingly effective.
This seems to fit my symptoms but my question is how can the PPF be fitted out of alignment? I've not done any work on it yet but given its multiple attachment bolts at both gearbox and diff casings, is it not by definition, aligned? I intend to have a closer look in a week or so when I get back from hols but any comments will be welcome!
I have done quite a few clutches / gearboxes and always simply used the obvious witness marks on the ppf to re align the bolts where they came from, its hardly rocket science.
I have never had any noise / vibration problems and I've fitted various clutches and flywheels.
However don't ask me to do yours, as I hate the job.
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