Grating 1st gear

[fasthamster]

Hi,
Engaging 1st gear is occasionally making a grating noise.
The gearbox oil level is fine and the clutch was a new installation in July 2015.
The car has not driven that many miles since July 2015, most recent history being October - yesterday mainly standing because of a lack of opportunity to drive and a grumpy brake disc upgrade.
The grating noise, first experienced yesterday, was not evident in October 2016.
My opinion is that this has happened because of a lack of being used.
Can anyone estimate what the problem could be, and a fix ?

Thanks

[mogbob]

Did you or the garage adjust the clutch pedal after fitting the new clutch and how many miles since the clutch change please ?
Was the clutch a full renewal , i.e a set , clutch housing , friction plate and release bearing.

Is the grating noise there when , with the car in neutral , dipping the clutch down and holding it there , for a moment or two ? Does it disappear when you release the pressure on the clutch pedal ?

If you could report back we can give you a more educated guess as to cause and cure. Thanks.
Bob

[liammonty]

Please don't be offended if you already know this, but there have been cases on here in the past where people didn't realise that 1st gear has no synchromesh in a Minor. As such, it will grate if you engage it when moving (even if only slightly) and indeed if you engage it quickly when stationary. It's normal practice to wait a moment after depressing the clutch before engaging 1st in order to let the gearbox innards stop moving, and subsequently crunching. Some people find that briefly engaging another (synchronised) gear, for example, second, before engaging first helps, as it stops the gears revolving prior to engaging gear. I'm not saying it's good practice, before anyone chastises me.

Assuming that the above isn't the case (you could be a champion double-declutcher for all I know, but i can't tell - hence please don't be offended if the above is obvious!), then I agree with all of mogbob's points!

[Boomlander]

Is there a small amount of play in the clutch pedal movement before the pedal encounters resistance from the clutch?
If not the clutch may not be disengaging fully when the pedal is depressed and this will result in difficulty selecting gears, especially 1st and reverse which have no synchromesh, and cause gear grating.

[liammonty]

Is there a small amount of play in the clutch pedal movement before the pedal encounters resistance from the clutch?
If not the clutch may not be disengaging fully when the pedal is depressed and this will result in difficulty selecting gears, especially 1st and reverse which have no synchromesh, and cause gear grating.

Wouldn't a large amount of play in the pedal, rather than a small amount, lead to this? If there's no play, it would lead to it disengaging too far. I think that for a 1098, the play should be around 1 1/2", and on a 948 around 3/4".

[Boomlander]

Agreed - too much play will lead to crunching gearchanges - - 1/2" would be fine.

[philthehill]

The correct pedal free movement is given in the BMC wksp manual as:-

948cc..........................3/4"

1098cc........................1 3/8" - 1 1/2"

Too much free movement may not allow the clutch to disengage (resulting in clutch drag) making it difficult to engage gear.

Too little free movement may result in the clutch over-centering resulting in the clutch fingers fouling the clutch centre plate assy.

It is best not to vary the pedal free movement far from that specified in the BMC wksp manual.

Unless you are very good at double declutching it is preferable to allow the 1st gear to stop rotating before engaging 1st gear.

One of the benefits of fitting a Ford gearbox is it has synchromesh on first gear so no crunching of gears on engaging first gear.

[fasthamster]

Thanks, thanks, thanks everyone.
I adjusted the free movement within the BMC specified range, and 1st gear engagement is better.
Must start double de-clutching, the benefits are worth considering.

[Nickol]

Check also if you can, the condition of the (original) rubber bearing on the clutch "layshaft" where it is secured to the Chassis rail. It tends to perish over time and is best replaced with a Nylon bush. In poor condition it leads to excessive Play in the clutch Operation which you do not notice on the pedal itself but by resticted movement on the clutch arm coming out of the bellhousing andhence difficulty in gettng into especially 1st gear.

[biomed32uk]

There is a poly bush available for that bush against the leg, it's worth checking the condition of the whole linkage assembly. The two bits of tin with the clevis pins through them are dreadful, the pins will wear through very well. A bit of wear everywhere adds up to quite a lot in total.

Next time I do something there I am going to fit Declans rose jointed assembly.

[ampwhu]

i have this same issue. today I fitted new gearbox and clutch. I can select 2, 3, 4 and drive in these gears. I can also change down 4, 3, 2 ok.

when stationary, I cannot select 1st or reverse. if I switch engine off, select gear and then start engine, I can pull away fine. clutch biting point is around halfway.

what am I missing?

[oliver90owner]

what am I missing?

Clutch adjustment, bent clutch centre disc, clutch cover arms not set properly, rough edges not yet worn off, wrong clutch assembly, wrong grade of oil.

Plenty to consider and may be more....

[ampwhu]

all except clutch adjustment can be ruled out. I've adjusted it to what the manual says.

[ampwhu]

as mentioned above, the car drives fine in 2,3 ,4 gears. just wont let me select 1st and reverse when stationary

[philthehill]

I suspect that the clutch is dragging i.e. clutch centre plate not completely disengaging from the flywheel/pressure plate.
Try reducing the free play in stages and see what happens.
The manual does not take into allowance individual clutches and their operation just assumes one size fits all.
Worth a try.

[oliver90owner]

How about another? Tight spigot bearing.

[ampwhu]

I suspect that the clutch is dragging i.e. clutch centre plate not completely disengaging from the flywheel/pressure plate.
Try reducing the free play in stages and see what happens.
The manual does not take into allowance individual clutches and their operation just assumes one size fits all.
Worth a try.

I think you were correct. I adjusted again this morning by trial and error. as its a new clutch, I'd not taken this into account. I now have all gears working. thanks for pointing me the right way.

[philthehill]

Well done

[dalebrignall]

another little trick is to lean the gear shift against 2nd to slow the gaerbox down before selecting 1st gear .