ZT gear change clunk/knock

[grendel]

Posted this on MG.org site yesterday but had no response, hoping maybe someone here can give me some advice.

Noticed a bit of a "clunk" (only way I can describe it) on gear change. From 1st to 2nd there is a pronounced clunking/knocking as you drop into gear, it's also there, but not so obvious, from 3rd gear into 4th. Into 1st, 3rd and 5th it's fine, just going into 2nd (especially) and 4th there's this knocking sound, I also get it changing down from 3rd into 2nd.

It sounds like it's coming from just in front of the drivers position, in front of the bulkhead, and seems, from what I can hear inside the car, as if it's nearer the back of the engine. It's not just when you're on the move or even with the engine running. Sit in traffic and run through the gears and it clunks away, even sitting with the engine off it's there when you select 2nd/4th.

Any ideas?

[Phil]

Hi, get someone to run through the gears with the engine off and look under the bonnet underneath the battery and you'll see the gear selector leavers on top of the gearbox moving you should be able to see if anything is itting them. On mine it was the hydraulic clutch pipe that had been routed incorrectly.

[Rich]

Yup, my money is on Phil's suggestion too :)

[Lates]

Evening Grendel, this may sound odd but have we looked after your car before ? I kinda recognise the user name if need be let me know the invoice number and I will see if I made any notes on your car.

Failing that check the lower rear pendulum mount for wear - heavy / sharp take off produces one hell of a knock through the bulkhead.

[Dave Goody]

Evening Grendel, this may sound odd but have we looked after your car before ? I kinda recognise the user name if need be let me know the invoice number and I will see if I made any notes on your car.

Failing that check the lower rear pendulum mount for wear - heavy / sharp take off produces one hell of a knock through the bulkhead.

I will second that, had a sharp clonk on changing gear, the only way to stop it was ride the clutch, turned out to be gearbox mounting, Dave

[grendel]

Had a quick look last night while someone was shifting gears for me, the noise isn't from the gear selector but seems to be coming from somewhere between the engine bay and the inside of the car, right in front of the drivers position, almost around the wiper motor area.

Like I said, it isn't a knock on movement of the car, ie when you take up the drive, it's there just by shifting gears when the engine isn't even running.

And Mr Lates, yes, you've looked after my car before, thermostat housing last year, which reminds me, must book in for a service with you.

[Lates]

Definate pendulum mounting. Lead time around 4/5 weeks atm mate.

[Mike]

Definate pendulum mounting. Lead time around 4/5 weeks atm mate.


Have you seen more than a few of these go Lates?

[Lates]

To be honest mike not that many this year to date. More assertvie drivers will suffer more than most.

[Rich]

More assertvie drivers will suffer more than most.

How very politically correct :D

[Lates]

;) as always Mr Rich. Sounded a little better than somebody who rags the a$$ out of their car :p:

[grendel]

;) as always Mr Rich. Sounded a little better than somebody who rags the a$$ out of their car :p:

That'll be me then!! :D

I think I prefer the "assertive driver" term, seems far more refined! Actually don't abuse the car (if that's the right word), most of my driving is stop/start traffic non-movement, though I do take the odd opportunity to give it a bit of a run out, whenever possible, but I'd hardly say I was the "boy-racer redline all the way" type.

So, pendulum mount seems to be the diagnosis, if it's nothing too serious I can live with it for a while until service time Mr Lates, unless you suggest otherwise. Service/MOT is due around June, so I'll get onto you soon for a booking date and a cost estimate if that's ok mate.

[Lates]

No problem bcfc ;) Your more than welcome. You may notice I dont delete emails :p:

[e668ecp]

Would you here this noise when the car is idling and/or at low revs?

I've still got a knocking noise.. appears to be when you decelerate and at 800 revs!

[e668ecp]

anyone?????

[Mike]

Hi mate, how are you doing and how's the car? :)

The noise described above you'd here most of the time, whether moving or stationary, because it is the pendulum mount and not a gearbox issue. I'm sure Lates 'll be along to advise, but if your noise is heard only under very specific conditions then it may be something else.

[e668ecp]

Hi Mike,

Car is fine.. passed its MOT but needed two new tyres as they had tears in them! NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- commuting and silly Leeds drivers on the A61!

The knocking noise can be heard almost all the time except when on the move. In the morning reversing out the garage you can heard it and when coasting or pulling up to or setting off at the lights i.e. basically at low speeds. Can hear it on block paved roads too

[Mike]

Ok. Are you sure it's the gearbox? I'd be checking for a broken spring meself - was the source of my knocking noise.

Good luck :)

ps I remember the A61 at Leeds and agree that it has some pretty stupid drivers using it :eek:

[e668ecp]

I've checked for a broken spring and its not that.... it appears to come from just underneath the transmission tunnel near to the bulk head

[Lates]

Has the vehicle had a none genuine exhaust fitted ?

[e668ecp]

Has the vehicle had a none genuine exhaust fitted ?

Yes but only the front section inc the cat. Was welded in.

Why?

[Lates]

Just a theory, I have seen one KV6 that with the engine moving under load the silencer boxes were knocking against the stiffener bars that run across the tunnel.

[e668ecp]

Just a theory, I have seen one KV6 that with the engine moving under load the silencer boxes were knocking against the stiffener bars that run across the tunnel.


I'll have a look.. Thank you

[maciejk]

i got a knock/clunk when down shifting to lower gears especially from 3rd to 2nd, it seems to be there even before i release the clutch all the way at times, the noise sounds like its coming from the back of the car any ideas?

[DMGRS]

From the back of the car, or the back of the engine?
I'm betting either this engine mount, or the exhaust knocking on something.

[maciejk]

its more of a clunk coming from the back of the car it seems rear suspension

[maciejk]

I noticed the clunk is getting worse now also happens when just letting off the gas pedal, when the car suddenly slows down & on downshifting gears, sometimes on pulling away, I now hear it coming from the front as well as the back, whole front suspension has been done, my lower engine mount looks good so does the upper, the round shaped rubber mount near the upper one looks ok too, don't know about the transmission mount, rear wishbone bushes look ok, & the back links don't seem to to have any freeplay that's with the car raised, could it be anything else?

[mrufff]

Macieju
try to check whole exhaust for movement .
I had same or similar clunk when foot of pedal and it was corroded exhaust mount.


Pozdrawiam kolege z Polski/ Greetings for a user from my Homeland

[maciejk]

I had my brake line replaced today, so I checked the exhaust today for play & noise it sounds ok, this sound is very specific to stabalizer link sound

[maciejk]

the clunk turned out to be a loose wheel nut, the one that holds the cv joint in place 32mm
#11 on the picture http://www.rimmerbros.co.uk/ItemImages/Large/GRID001540.gif
my mechanics changed the whole suspension plus front disc brakes, I asked them if they tightened the big nut, they said no because they didn't need to in order to take the disc off, so I didn't pay much attention to it, the wheel soon started making clunking noises when going over pot holes & bumps & more clunk with gear changes, thought my CV joint was bad, tightened the nut & the clunking went away, I wonder how these morons did the alignment with that nut loose, perhaps it wasn't that loose when they did it.

[DMGRS]

The nut being loose wouldn't affect the alignment - it's only to hold the shaft into the hub and provide drive to the wheels. It'd certainly cause a 'clunk' if it was loose, though!

Glad it's all sorted. :)